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Pipeline Pressure Modules

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CALCULATOR MODULE : Line Pipe Wall Thickness And Diameter   ±

Calculate pipe nominal wall thickness, minimum wall thickness and pressure design wall thickness from pipe schedule diameter and wall thickness.

For most pipeline codes the pressure design thickness equals the nominal wall thickness minus the fabrication allowance and the corrosion allowance (use the with tolerance calculator). For some codes the fbrication allowance is ignored and the pressure design thickness equals the nominal wall thickness minus the corrosion allowance.

Use the Result Table option to display the results for the selected pipe schedule and pipe diameter.

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CALCULATOR MODULE : Plastic Pipe Rated Pressure   ±

Calculate plastic pipe maximum allowable design pressure from pipe schedule diameter and wall thickness or dimension ratio.

Use the Result Table option to display the results for the selected pipe diameter. The dimension ratio is based on the Renard R10 series. The standard dimension ratio SDR equals R10 + 1 and is calculated from the outside diameter divided by the pressure design wall thickness. The standard internal dimension ratio SIDR equals R10 - 1 and is calculated from the inside diameter divided by the pressure design wall thickness. The pressure design wall thickness is equal to the nominal wall thickness minus the fabrication allowance and the mechanical allowance. The mechanical allowance includes allowances for threads, machining, glueing, corrosion, erosion, and mechanical damage.

The allowable pressure can be calculated directly from the dimension ratio and the minimum required strength (MRS). A service design coefficient (C value) of 1.25 is suitable for water pipes. For other fluids a higher C value should be used.

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CALCULATOR MODULE : ASME B31.3 Process Piping Line Pipe Schedule   ±

Calculate ASME B31.3 process piping schedule for metal and plastic piping.

The piping minimum wall thickness and hoop stress wall thickness schedule can be calculated from the nominal wall thickness, fabrication tolerance and corrosion allowance.

`tm = tn - fa `
`tm = (1 - fx) tn `
`t = tm - c `

where :

tn = nominal wall thickness
tm = minimum wall thickness
t = hoop stress wall thickness
c = corrosion thickness allowance
fa = negative fabrication thickness allowance
fx = negative fabrication fraction

The minimum wall thickness equals the nominal wall thickness minus the fabrication allowance. The pressure containment wall thickness equals the nominal wall thickness minus the fabrication tolerance, and minus the corrosion allowance. Fabrication tolerance can be defined by either a fabrication allowance, or a fabrication fraction. The pipe diameter can be defined by either the outside diameter or the inside diameter. Use the Result Table option to display a table of pipe dimensions versus wall thickness, wall tolerance, or piping diameter for metal pipes, or pipe dimension versus wall thickness for plastic pipes.

Calculate metal piping maximum and minimum diameter schedule. Use the Result Table option to display a table of pipe dimensions versus wall thickness, wall tolerance, or piping diameter.

Calculate piping unit mass and joint mass schedule for metal and plastic piping. Use the Result Table option to display a table of pipe dimensions and mass versus wall thickness.

Calculate piping tensile stress, yield stress and allowable schedule for metal piping. Use the Result Table option to display a table of stress versus material type.

Plastic pipe wall thickness can be defined by wall thickness or diameter ratio (DR or IDR). Select standard diameter ratios from the plastic pipe schedule (SDR or SIDR), or use user defined diameter ratios (DR or IDR).

Reference : ANSI/ASME B31.3 : Process Piping (2018)

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CALCULATOR MODULE : ASME B31.3 Process Piping Wall Thickness   ±

Calculate ASME B31.3 process piping wall thickness from temperature for low pressure steel pipe (Table A-1), high pressure steel pipe (Table K-1), and plastic piping.

Allowable stress for steel pipe is calculated from Table A-1 and Table K-1 US values (US units govern). Change units on the setup page. Stress values can be extrapolated for temperatures above the data range (care is required when using extrapolated values). The wall thickness calculations are valid for internal overpressure only. For combined internal and external pressure use the pressure difference in the calculations.

Use the Data Plot option to plot the allowable stress versus temperature for the selected material. Use the Data Table option to display the data table in the popup window (Table A-1, or Table K-1). Use the Result Table option to display a table of wall thickness and allowable pressure versus material type (for the calculate wall thickness option the allowable pressure equals the design pressure. for the specified wall thickness option the wall thickness equals the specified wall thickness). Refer to the help pages for notes on the data tables. Change units on the setup page. Use the workbook ASME B31.3 data tables to look up allowable stress data.

Note : The choice of high pressure versus low pressure service is at the discretion of the owner (section FK300). The ASME B16.5 Class 2500 pressure temperature rating for the material group is often used as a criteria.

Reference : ANSI/ASME B31.3 : Process Piping (2018)

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CALCULATOR MODULE : ASME B31.3 Process Piping Hoop Stress   ±

Calculate ASME B31.3 process piping hoop stress for low pressure steel pipe (Table A-1), high pressure steel pipe (Table K-1), and plastic piping.

The hoop stress can be calculated for either the minimum wall thickness (nominal wall thickness minus fabrication allowance), or the pressure design wall thickness (minimum wall thickness minus the corrosion allowance). For operation the hoop stress should be ≤ the design stress. For pressure tests, the hoop stress should be ≤ 100% of yield stress for hydrotest, or ≤ 90% of yield stress for pneumatic tests. For combined internal and external pressure use the pressure difference in the calculations. Use the workbook ASME B31.3 data tables to look up allowable stress data.

Note : The choice of high pressure versus low pressure service is at the discretion of the owner (section FK300). The ASME B16.5 Class 2500 pressure temperature rating for the material group is often used as a criteria.

Reference : ANSI/ASME B31.3 : Process Piping (2018)

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CALCULATOR MODULE : ASME B31.3 Process Piping Hydrotest Pressure   ±

Calculate ASME B31.3 process piping hydrotest and pneumatic leak test pressure and hoop stress check. The test pressure should be 1.5 times the design pressure for hydrotest, or 1.1 times the design pressure for pneumatic test. An allowance should be made for the pipe design temperature.

Hoop stress can be calculated for either the minimum wall thickness (nominal wall thickness minus fabrication allowance), or the pressure design wall thickness (minimum wall thickness minus the corrosion allowance). Minimum wall thickness is recommended for new piping, or piping in as new condition. The pressure design wall thickness is recommended for corroded piping. The hoop stress should be ≤ 100% of yield for hydrotest, or ≤ 90% of yield for pneumatic tests. The test pressure should be ≤ 1.5 x the pressure rating for pressure rated components.

For piping systems with combined internal and external pressure during operation, the test pressure should be calculated from the internal pressure only. The hoop stress should be calculated from the pressure difference during testing. Use the workbook ASME B31.3 data tables to look up allowable stress data.

Note : The choice of high pressure versus low pressure service is at the discretion of the owner (section FK300). The ASME B16.5 Class 2500 pressure temperature rating for the material group is often used as a criteria.

Reference : ANSI/ASME B31.3 : Process Piping (2018)

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CALCULATOR MODULE : ASME B31.3 Process Piping Branch Reinforcement   ±

Calculate ASME B31.3 process piping required branch reinforcement for welded and extruded branches.

The calculations are valid for right angle welded branches, angled welded branches ≥ 45 degrees, and right anngle extruded branches. Extruded branches must be used for high pressure piping. Use the workbook ASME B31.3 data tables to look up allowable stress data.

Reference : ANSI/ASME B31.3 : Process Piping (2018)

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CALCULATOR MODULE : ASME B31.3 Process Piping Blank Flange   ±
CALCULATOR MODULE : ASME B31.3 Process Piping Bend   ±

Calculate ASME B31.3 process piping minimum thickness for formed bends, and allowable pressure for miter bends.

Minimum thickness of formed bends is calculated for the inside radius, the oputside radius, and the centerline radius. Bend thinning on the outside radius is estimated using the method from ASME B31.1. The estimated minimum bend thickness after thinning should be ≥ the required minimum bend thickness on the outside radius (extrados). Use the goal seek option to calculate the required straight pipe nominal wall thickness (before bending), for the minimum thickness on the outside radius (after bending).

The allowable pressure for miter bends is calculated from the nominal wall thickness. Use the goal seek option to calculate the required miter bend nominal wall thickness for the design pressure. Use the workbook ASME B31.3 data tables to look up allowable stress data.

Reference : ANSI/ASME B31.3 : Process Piping (2018)

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CALCULATOR MODULE : ASME B31.3 Process Piping Design Pressure   ±

Calculate ASME B31.3 process piping design pressure for low pressure steel pipe (Table A-1), high pressure steel pipe (Table K-1), and plastic piping.

The design pressure is calculated from the pipe diameter, wall thickness, wall thickness tolerance and allowable stress (Table A-1 and Table K-1 US values : US units govern). The hoop stress is equal to the design stress at the design pressure. Change units on the setup page. Stress values can be extrapolated for temperatures above the data range (care is required when using extrapolated values). For combined internal and external pressure, the design pressure equals the pressure difference.

Use the Result Table option to display a table of design pressure versus wall thickness or design pressure versus material type. Use the Data Plot option to plot the design stress versus temperature for the selected material. Use the Data Table option to display the data table in the popup window (Table A-1, or Table K-1). Refer to the help pages for notes on the data tables (click the resources button on the data bar). Use the workbook ASME B31.3 data tables to look up allowable stress data.

Note : The choice of high pressure versus low pressure service is at the discretion of the owner (section FK300). The ASME B16.5 Class 2500 pressure temperature rating for the material group is often used as a criteria.

Reference : ANSI/ASME B31.3 : Process Piping (2018)

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CALCULATOR MODULE : ASME B31.4 Liquid Pipeline Hydrotest Pressure   ±

Calculate ASME B31.4 oil and liquid pipeline test pressure and hoop stress check for onshore and offshore pipelines.

Select the appropriate line pipe schedule (ASME or ISO etc) and stress table (API, ASM, DNV etc), and material. Hoop stress is calculated using Barlow's formula. For offshore pipelines either the pipe outside diameter or the mid wall diameter can be used to calculate hoop stress. The test pressure and hoop stress should be checked for all elevations. Use the Result Plot option to plot the required test pressure versus elevation, or hoop stress verus elevation for user defined test pressure.

Reference : ANSI/ASME B31.4 : Pipeline Transportation Systems For Liquids And Slurries (2012)

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CALCULATOR MODULE : ASME B31.4 Liquid Pipeline Local Pressure   ±
CALCULATOR MODULE : ASME B31.4 Liquid Pipeline Design Pressure   ±

Calculate ASME B31.4 oil and liquid pipeline maximum allowable design pressure from pressure design wall thickness and allowable stress.

For subsea pipelines the allowable pressure is the maximum allowable local pressure difference across the pipe wall. The pressure difference equals the internal pressure minus the external pressure. For onshore pipelines the allowable pressure is the maximum allowable local internal pressure. The local internal and external pressure varies with elevation. Use the Result Table option to display the allowable pressure for the selected pipe diameter schedule.

Reference : ANSI/ASME B31.4 : Pipeline Transportation Systems For Liquids And Slurries (2012)

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CALCULATOR MODULE : ASME B31.8 Gas Pipeline Wall Thickness   ±

Calculate ASME B31.8 gas pipeline wall thickness from hoop stress for onshore and offshore pipelines.

Select the appropriate line pipe schedule (ASME or ISO etc), and stress table (API, ASME or DNV), or use the user defined options. Pipe pressure can either be calculated from elevation, or user defined. For metal pipeline the pressure design thickness equals the nominal wall thickness minus the corrosion allowance. Fabrication tolerance is ignored. The wall thickness should be checked for all pipeline elevations. A wall thickness should be specified which is greater than or equal to the maximum calculated wall thickness (usually by selecting the next highest schedule thickness). Use the Result Plot option to plot the calculated wall thickness versus elevation, and the hoop stress versus elevation for the specified wall thickness.

Reference : ANSI/ASME B31.8 : Gas Transmission And Distribution Piping Systems (2018)

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CALCULATOR MODULE : ASME B31.8 Gas Pipeline Hydrotest Pressure   ±

Calculate ASME B31.8 gas pipeline test pressure and hoop stress check for onshore and offshore pipelines.

Select the appropriate line pipe schedule (ASME or ISO etc), and stress table (API, ASME or DNV), or use the user defined options. For metal pipeline the pressure design thickness equals the nominal wall thickness minus the corrosion allowance. Fabrication tolerance is ignored. Pipe pressure can either be calculated from elevation, or user defined. The test pressure should be checked for all pipeline elevations. A test point test pressure should be specified which is greater than or equal to the maximum calculated test pressure (usually by rounding up the maximum test pressure). Use the Result Plot option to plot the test pressure versus elevation, and the hoop stress versus elevation for the specified test pressure.

Reference : ANSI/ASME B31.8 : Gas Transmission And Distribution Piping Systems (2018)

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CALCULATOR MODULE : ASME B31.8 Gas Pipeline Maximum Allowable Operating Pressure   ±

Calculate ASME B31.8 gas pipeline MAOP from the design pressure and the test pressure.

The design pressure is the minimum value of allowable pressure at all points on the pipeline. If the design pressure is not known, use the hoop stress calculators to calculate the design pressure. Use the goal seek option to calculate the allowable pressure at the allowable stress at all points on the pipeline. The minimum value of allowable pressure is the design pressure. Use the pressure design wall thickness for the hoop stress calculations.

The test pressure is the minimum value of the local test pressure at all points on the pipeline. If the minimum test pressure is not known (only the test pressure at the test location is known), use the test pressure calculators to calculate the local test pressure from the test pressure at the test location, at all points on the pipeline. Use the minimum value of local test pressure as the test pressure.

Reference : ANSI/ASME B31.8 : Gas Transmission And Distribution Piping Systems (2018)

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CALCULATOR MODULE : ASME B31.8 Gas Pipeline Local Pressure   ±
CALCULATOR MODULE : ASME B31.8 Gas Pipeline Design Pressure   ±

Calculate ASME B31.8 gas pipeline maximum allowable design pressure from allowable stress and pressure design wall thickness.

For onshore pipelines and offshore platform piping the allowable pressure is the maximum allowable design pressure for the pipeline location class and facility type. For submerged offshore pipelines the allowable pressure is the maximum allowable pressure difference (internal pressure minus external pressure). Use the Result Table option on the plot bar to display the allowable pressure for the selected pipe diameter.

Reference : ANSI/ASME B31.8 : Gas Transmission And Distribution Piping Systems (2018)

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CALCULATOR MODULE : ASME B31G Pipe Corrosion Defect   ±

Calculate ASME B31G piping level 0 corrosion defect assessment for blunt defects (corrosion defects or other defects).

The level 0 assessment is useful as a screening check. The allowable defect length is calculated from the maximum defect depth. The calculation is taken from ASME B31G 1999 (original ASME B31G). The level 0 check is suitable for blunt defects of all types, including corrosion, mechanical damage and grinding repairs etc. For crack type defects the NG-18 crack defect calculators are recommended. The RSTRENG method (effective area method) can also be used for blunt type defects. The temperature derating calculation is from ASME B31.8. Material specific test data should be used if it is available.

Defects failing the level 0 check should be checked with a level 1 or level 2 assessment (see module links below). Use the level 1 assessment for simple defects from defect length and depth using either the original ASME B31G equation, or the modified ASME B31G equation. Use the level 2 assessment for complex defects from the defect river bottom profile.

Reference : ANSI/ASME B31G Manual For Determining The Remaining Strength Of Corroded Pipelines (2012)

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CALCULATOR MODULE : ASME B31G Level 1 Defect Assessment   ±

Calculate ASME B31G level 1 corrosion defect assessment for blunt type defects.

The level 1 assessment calculates the allowable pressure from the maximum defect depth and defect length, using either the original ASME B31G method (1999), or the modified ASME B31G method. Pressure derating is required if the allowable pressure is less than the maximum operating pressure.

The flow stress can be calculated as either 1.1 x SMYS, SMYS + 69 MPa, or 1/2 (SMYS + SMTS). For pipelines operating at high temperature, the SMYS and SMTS should be derated.

For submerged pipelines, or to calculate the allowable pressure at a reference elevation, use the level 1 calculator including elevation. The allowable local pressure is calculated including external pressure (use the external pressure = 0 for dry pipelines). The allowable reference pressure is calculated from the local allowable pressure, and the relative elevation.

ASME B31G is suitable for blunt defects of all types, including corrosion, mechanical damage and grinding repairs etc. For crack type defects the NG-18 crack defect calculators are recommended. The effective area method can also be used for blunt defects.

Reference : ANSI/ASME B31G Manual For Determining The Remaining Strength Of Corroded Pipelines (2012)

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CALCULATOR MODULE : ASME B31G Level 2 Defect Assessment   ±

Calculate ASME B31G level 2 corrosion defect assessment for blunt type defects.

The level 2 assessment calculates the allowable pressure from the defect "river bottom" profile using the effective area method (also known as the RSTRENG method). Pressure derating is required if the allowable pressure is less than the maximum operating pressure.

The flow stress can be calculated as either 1.1 x SMYS, SMYS + 69 MPa, or 1/2 (SMYS + SMTS). For pipelines operating at high temperature, the SMYS and SMTS should be derated.

For submerged pipelines, or to calculate the allowable pressure at a reference elevation, use the level 1 and level 2 calculators including elevation. The allowable local pressure is calculated including external pressure (use the external pressure = 0 for dry pipelines). The allowable reference pressure is calculated from the local allowable pressure, and the relative elevation.

ASME B31G is suitable for blunt defects of all types, including corrosion, mechanical damage and grinding repairs etc. For crack type defects the NG-18 crack defect calculators are recommended. The effective area method can also be used for blunt defects.

Reference : ANSI/ASME B31G Manual For Determining The Remaining Strength Of Corroded Pipelines (2012)

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CALCULATOR MODULE : ASME B31.1 Power Piping Hydrotest Pressure   ±

Calculate ASME B31.1 power piping hydrotest pressure and pneumatic leak test pressure for steel pipe and plastic piping.

The test pressure should be ≥ 1.5 times the design pressure for hydrotest, and ≥ 1.2 times the design pressure for pneumatic tests. The hoop stress during testing should be ≤ 90% of the yield stress. Hoop stress can be calculated for either the minimum wall thickness (nominal wall thickness minus fabrication allowance), or the pressure design wall thickness (minimum wall thickness minus the corrosion allowance).

For piping systems with combined internal and external pressure the test pressure should be calculated from the internal pressure. The hoop stress is calculated from the pressure difference during testing. Use the workbook ASME B31.1 data tables to look up allowable stress data.

Reference : ANSI/ASME B31.1 : Power Piping (2014)

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CALCULATOR MODULE : ASME B31.1 Power Piping Design Pressure   ±

Calculate ASME B31.1 power piping design pressure from the design temperature.

The design stress (SE) is calculated from tables A-1 to A-9. For temperatures above the data range, select either constant value, constant slope, or zero value (engineering judgement is required). The weld factor W is relevant for temperatures in the creep range. For temperatures below the creep onset temperature W = 1. The ASME Y factor can either be calculated, or user defined. For thick wall pipe (D/tm < 6) Y is calculated from the diameter. For thin wall pipe Y is calculated from the temperature. For combined internal and external pressure use the pressure difference in the calculations.

Use the table data option for a table of allowable pressure versus wall thickness for the selected pipe schedule and diameter. Use the data plot option to plot the allowable stress versus temperature for the selected material. Use the Data Table option to display the data table in the popup window. Use the Result Table option to display a table of allowable pressure versus material type, or allowable pressure versus wall thickness. The calculations use SI standard units. Change input and output units on the setup page. Refer to the help pages for notes on the data tables (click the resources button on the data bar). Use the workbook ASME B31.1 data tables to look up allowable stress data.

Reference : ANSI/ASME B31.1 : Power Piping (2014)

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CALCULATOR MODULE : ASME B31.1 Power Piping Steam Pressure Relief   ±

Calculate ASME B31.1 power piping steam mass flow rate for pressure relief valves, headers and vents.

For pressure relief valves the mass flow rate can be calculated for isentropic or isothermal flow. The pressure relief valve is assumed to exit directly to ambient pressure. If the ambient pressure is less than the critical pressure the flow is critical (Mc = 1 for isentropic flow and Mc = √(1/γ) for isothermal flow). If exit pressure is greater than the critical nozzle pressure, the flow is sub critical (M < Mc). For isothermal flow a suitable isothermal temperature should be determined. The valve nozzle orifice diameter and cross section area can be calculated from API letter designation (API 526 type D to T), or user defined.

For a combined pressure relief valve and pressure relief header, the mass flow rate can be calculated for

  • Isentropic nozzle and adiabatic header
  • Isentropic nozzle and isothermal header
  • Isothermal nozzle and isothermal header

The pressure relief valve is assumed to exit directly into the header. If the header inlet pressure is less than or equal to the nozzle critical pressure the nozzle flow is critical, and the mass flow rate is restricted by the nozzle. The header inlet pressure is calculated so that the header mass flow rate equals the nozzle mass flow rate. If the header inlet pressure is greater than the critical nozzle pressure, the nozzle flow is sub critical (M < Mc), and the mass flow rate is restricted by the header. The mass flow rate is calculated so that the header inlet pressure is equal to the nozzle pressure. The mass flow rate through the nozzle is always equal to the mass flow rate through the header.

Pressure relief headers are normally part of a pressure relief system, and are usually attached to an upstream device such as a pressure relief valve, a pressure relief vent, or another pressure relief header. The inlet pressure of the header is less than or equal to exit pressure from the upstream device. The header should be sized so that the calculated header mass flowrate is greater than or equal to the mass flowrate of the upstream device. For headers attached to multiple upstream devices, the header mass flowrate is divided by the number of devices. If the header is oversized, the header inlet pressure will reduce so that the actual header mass flowrate is equal to the upstream mass flowrate (there is a pressure drop between the upstream exit and the header inlet).

Pressure relief vents are constant diameter piping, usually with either a valve or a burst disk. Vents usually exit either to atmosphere, or into a header. If the ambient pressure is less than the critical exit pressure exit flow is critical. If the ambient pressure is greater than the critical exit pressure, exit flow is sub critical (M < Mc). The header or vent inlet flow is assumed to be sub critical for all flow conditions. Header and vent pressure losses are calculated from the pressure loss factor (fld = fL/D + K). The Darcy friction factor f is calculated for fully turbulent flow using the rough pipe equation. Minor losses can be included by the minor loss K factor, and should include valves and bends etc. The discharge coefficient can also be used for minor losses, and as a safety factor.

Reference : ANSI/ASME B31.1 : Power Piping (2014)

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CALCULATOR MODULE : ASME B31.5 Refrigeration Piping Hydrotest Pressure   ±

Calculate ASME B31.5 refrigeration piping hydrotest and pneumatic leak test pressure and hoop stress check. Use the allowable stress calculators to calculate the yield stress from the design temperature.

The test pressure should be 1.5 times the design pressure for hydrotest, or 1.1 times the design pressure for pneumatic test. Hydrotest should be used for secondary cooling piping only. Hydrotest should not be used for refrigeration piping.

Hoop stress can be calculated for either the minimum wall thickness (nominal wall thickness minus fabrication allowance), or the pressure design wall thickness (minimum wall thickness minus the corrosion allowance). Minimum wall thickness is recommended for new piping, or piping in as new condition. The pressure design wall thickness is recommended for corroded piping. The hoop stress should be ≤ 90% of yield for hydrotest or pneumatic tests.

For piping systems with combined internal and external pressure during operation, the test pressure should be calculated from the internal pressure only. The hoop stress should be calculated separately from the pressure difference during testing (use the hoop stress calculator). Use the workbook ASME B31.5 data tables to look up allowable stress data.

Reference : ANSI/ASME B31.5 : Refrigeration Piping And Heat Transfer Components (2013)

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CALCULATOR MODULE : ASME B31.5 Refrigeration Piping Design Pressure   ±

Calculate ASME B31.5 refrigeration piping maximum allowable design pressure from wall thickness and design temperature .

Allowable stress is calculated from temperature using Table 502.3.1 (US values). Change units on the setup page. Stress values can be extrapolated for temperatures above the data range (care is required when using extrapolated values). For combined internal and external pressure the allowable pressure is equal to the maximum allowable pressure difference.

Use the data plot option to plot the allowable stress versus temperature for the selected material. Use the Data Table option to display the relevant data table. Use the Result Table option to display a table of allowable pressure versus wall thickness for the selected pipe schedule.

Reference : ANSI/ASME B31.5 : Refrigeration Piping And Heat Transfer Components (2013)

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CALCULATOR MODULE : Pipeline Hoop Stress   ±
CALCULATOR MODULE : Pipeline Test Pressure   ±
CALCULATOR MODULE : Pipeline Collapse Pressure   ±
CALCULATOR MODULE : Pipeline Axial Load   ±

Calculate pipeline global (or external) axial load, and pipe wall axial load from temperature and pressure.

Fully restrained axial load is due to the difference between installation temperature and pressure, and the operating temperature and pressure, and including residual installation loads. External pressure is assumed constant. Unrestrained load is due to the pipe end cap pressure force.

The axial load is calculated using the thick wall formula (API RP 1111 and DNV OS F101). For onshore and offshore pipelines the internal pressure is assumed zero during installation, and the external pressure is assumed constant for installation and operation. For piping the internal and external pressure are assumed zero during installation. The design factor should include all relevant factors (eg quality factor E and stress factor F etc).

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CALCULATOR MODULE : Pipeline Local Pressure   ±
CALCULATOR MODULE : Pipeline Maximum Allowable Design Pressure   ±

Calculate pipeline maximum allowable design pressure from allowable stress and wall thickness.

The design factor should include all relevant factors (eg quality factor E and stress factor F etc). The allowable pressure is calculated so that the hoop stress equals the allowable stress. The allowable internal pressure includes the effect of external pressure. For onshore (dry) pipelines the external pressure should be set to zero. Use the Result Table option to display the results for the selected pipe diameter table.

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CALCULATOR MODULE : DNVGL ST F101 Submarine Pipeline Wall Thickness   ±

Calculate DNVGL-ST-F101 submarine pipeline wall thickness from local incidental pressure.

Local incidental pressure can be calculated from the design pressure, calculated from the reference incidental pressure, or can be user defined. External pressure should be calculated for the minimum local water depth. The pipeline wall thickness must be calculated for the maximum pressure differential at all points on the pipeline or pipeline section. For submarine pipelines where the internal fluid density is less than the external fluid density, the maximum pressure differential occurs at the highest submerged location for the pipeline or pipeline section. For the platform zone the highest differential pressure occurs at the riser splash zone. Use the Result Plot option to plot the required wall thickness versus elevation.

Reference : DNVGL-ST-F101 : Submarine Pipeline Systems (Download from the DNVGL website)

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CALCULATOR MODULE : DNVGL ST F101 Submarine Pipeline Hydrotest Pressure   ±

Calculate DNVGL-ST-F101 submarine pipeline system test pressure and mill test pressure.

The system test pressure is calculated from the local incidental pressure. The required system test pressure and mill test pressure should be calculated for all points on the pipeline or pipeline section. Use the Result Plot option to plot the test pressure and hoop stress from minimum to maximum elevation.

Reference : DNVGL-ST-F101 : Submarine Pipeline Systems (Download from the DNVGL website)

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CALCULATOR MODULE : DNVGL ST F101 Submarine Pipeline Collapse Pressure   ±

Calculate DNVGL-ST-F101 submarine pipeline external collapse pressure and propagating buckle pressure.

The external pressure should be calculated for the maximum water depth. Propagating buckles are only a problem if collapse has occurred. Buckle arrestors may be required to minimse the risk of propagating buckling.

Reference : DNVGL-ST-F101 : Submarine Pipeline Systems (Download from the DNVGL website)

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CALCULATOR MODULE : DNVGL ST F101 Submarine Pipeline Local Buckling   ±

Calculate DNVGL-ST-F101 submarine pipeline local buckling checks for combined loading.

The load controlled calculators should only be used for elastic deformation (check that the equivalent stress is less than the yield stress).

The displacement controlled calculators can be used for compressive elastic and plastic deformation. Elastic strains are calculated using the elastic modulus, and should not be used in the plastic range. Plastic strains should be calculated using finite element analysis (FEA). Use the allowable stress design (ASD) calculators for displacement controlled loads which include torsion.

Reference : DNVGL-ST-F101 : Submarine Pipeline Systems (Download from the DNVGL website)

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CALCULATOR MODULE : DNVGL ST F101 Submarine Pipeline Bend Allowable Stress Design (ASD)   ±

Calculate DNVGL-ST-F101 submarine pipeline allowable stress design (ASAD) check for combined loading. The allowable stress design (ASD) check can be used for pipeline induction bends with combined loading which includes a torsion load. The allowable stress design (ASD) check is a von Mises equivalent stress check.

Reference : DNVGL-ST-F101 : Submarine Pipeline Systems (Download from the DNVGL website)

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CALCULATOR MODULE : DNVGL ST F101 Submarine Pipeline Incidental Pressure   ±

Calculate DNVGL-ST-F101 submarine pipeline incidental pressure from design pressure and elevation.

The reference incidental pressure (the incidental pressure at the reference elvation) is calculated from the design pressure at the reference elevation. The local incidental pressure (the incidental pressure at the local elvation) is calculated from the reference incidental pressure and the relative elevation. Use the Result Plot option to plot local pressure and reference pressure versus elevation.

Reference : DNVGL-ST-F101 : Submarine Pipeline Systems (Download from the DNVGL website)

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CALCULATOR MODULE : DNVGL ST F101 Submarine Pipeline Hoop Stress   ±

Calculate DNVGL-ST-F101 submarine pipeline hoop stress from local incidental pressure.

The local incidental pressure can either be calculated, or user defined. For temporary conditions the actual local pressure can be used (eg for system pressure test). External pressure should be calculated for the minimum local water depth (lowest astronomical tide minus storm surge). For temporary conditions storm surge can be ignored. For pressure containment use wall thickness t1. For other cases use wall thickness t2.

Reference : DNVGL-ST-F101 : Submarine Pipeline Systems (Download from the DNVGL website)

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CALCULATOR MODULE : DNVGL ST F101 Submarine Pipeline Design Pressure And Burst Pressure   ±

Calculate DNVGL-ST-F101 submarine pipeline maximum allowable design pressure and burst pressure from the pressure design wall thickness (nominal wall thickness minus fabrication allowance and corrosion allowance).

For platform piping the allowable pressure is the maximum allowable local incidental pressure. For subsea pipelines the allowable pressure is the maximum allowable local pressure difference (local incidental pressure minus local external pressure). Use the Result Table option to display the results for the selected pipe schedule and pipe diameter.

Reference : DNVGL-ST-F101 : Submarine Pipeline Systems (Download from the DNVGL website)

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CALCULATOR MODULE : High Temperature High Pressure (HTHP) Pipeline Line Pipe Schedule   ±
CALCULATOR MODULE : Hot Pipeline Temperature Decay Curve   ±
CALCULATOR MODULE : Hot Pipeline End Expansion   ±
CALCULATOR MODULE : Hot Pipeline Hobbs Lateral And Upheaval Buckling   ±
CALCULATOR MODULE : Hot Pipeline Upheaval Buckling   ±

Calculate high temperature pipeline upheaval buckling using either the Hobbs method, the Pipeng method, or the LRSTAR method.

The Hobbs method can be used for used for pipelines lying on the seabed. The LRSTAR and Pipeng methods are suitable for buried pipelines, and have been developed using the results from finite element analysis (FEA). The LRSTAR method uses a cubic spline fit for the dimensionless Richards length number and Richards weight number. The Pipeng method uses a simple mathematical relationship between the Calladine Length number and the Calladine load number based on beam theory.

The Hobbs method calculates the initiation temperature from the global axial load, the load outside the slip zone, and hence accounts for the expansion of the pipe prior to buckling. The Pipeng method and LRSTAR method calculate the initiation temperature from the axial load in the buckle, and do not account for the expansion of the pipe prior to buckling. The Pipeng method and LRSTAR method are therefore slightly conservative. In addition, the LRSTAR method includes a built in design factor. The LRSTAR method is therefore more conservative than the Pipeng method.

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CALCULATOR MODULE : Hot Pipeline Lateral Buckling   ±
CALCULATOR MODULE : Hot Pipeline Upheaval Buckling Trigger   ±

Calculate high temperature pipeline upheaval buckling trigger height using Hobbs method.

Upheaval buckling triggers are used to initiate controlled buckling of high temperature high pressure pipelines. The trigger height should be designed so that the upheaval buckling initiation temperature is lower than the lateral buckling initiation temperature for all four lateral buckling modes. The triggers should be spaced according to the buckle initiation slip length. Use the Result Plot option to display the buckle initiation temperature versus either lateral out of straightness or trigger height, and use the goal seek option to calculate the required trigger height.

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CALCULATOR MODULE : Hot Pipeline Walking   ±
CALCULATOR MODULE : Hot Pipeline Soil Friction   ±
CALCULATOR MODULE : Hot Pipeline Local Pressure   ±
CALCULATOR MODULE : Hot Pipeline Prop   ±
CALCULATOR MODULE : API RP 1111 Pipeline Wall Thickness   ±

Calculate API RP 1111 limit state pipeline wall thickness from local pressure.

The pipe wall thickness should be calculated for the maximum pressure difference at all points on the pipeline or pipeline section. Internal pressure is calculated from reference pressure and elevation. The internal fluid density is assumed constant. External pressure should be calculated for the minimum local water depth (lowest astronomical tide and allowance for storm surge etc). API RP 1111 should only be used for line pipe with a weld joint factor = 1.0.

Note : The derated yield stress and tensile stress are used in the API RP 1111 calculations.

Reference : API RP 1111 : Design, Construction, Operation, and Maintenance of Offshore Hydrocarbon Pipelines (Limit State Design) (2011)

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CALCULATOR MODULE : API RP 1111 Pipeline Hoop Stress   ±
CALCULATOR MODULE : API RP 1111 Pipeline Test Pressure   ±
CALCULATOR MODULE : API RP 1111 Pipeline Collapse Pressure   ±
CALCULATOR MODULE : API RP 1111 Pipeline Combined Loading   ±

Calculate API RP 1111 limit state pipeline combined loading check.

For the external pressure check, the external pressure should be calcuated for the maximum water depth (highest astronomical tide plus storm surge). The internal pressure should be the maximum sustainable pressure (normally zero).

For the axial load check, the axial load can be calculated for either fully constrained pipeline, unconstrained pipeline, or user defined loads.

Reference : API RP 1111 : Design, Construction, Operation, and Maintenance of Offshore Hydrocarbon Pipelines (Limit State Design) (2011)

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CALCULATOR MODULE : API RP 1111 Pipeline Burst Pressure   ±
CALCULATOR MODULE : API RP 1111 Pipeline Local Pressure   ±
CALCULATOR MODULE : API RP 1111 Pipeline Design Pressure   ±

Calculate API RP 1111 limit state pipeline maximum allowable design pressure from wall thickness and burst stress.

Burst stress is calculated from the average of the yield stress and the ultimate tensile stress. Burst pressure can be calculated from either equation 4, or equation 5. The maximum test pressure, incidental pressure and design pressure are calculated from the burst pressure. The allowable pressure is calculated so that the hoop stress equals the allowable stress. For submerged pipelines the allowable pressure equals the pressure difference (internal pressure minus external pressure).

Reference : API RP 1111 : Design, Construction, Operation, and Maintenance of Offshore Hydrocarbon Pipelines (Limit State Design) (2011)

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CALCULATOR MODULE : API RP 1102 Pipeline Design Stress And Design Pressure   ±

Calculate API RP 1102 pipeline allowable stress and maximum allowable design pressure from wall thickness.

The allowable stress is calculated from the SMYS, diameter and wall thickness. The allowable pressure is calculated so that the hoop stress equals the allowable stress, allowing for pipe wall allowances. Use the Result Table option to display the calculated stress and allowable pressure values.

Reference : API RP 1102 : Steel Pipelines Crossing Railroads and Highways (2012)

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CALCULATOR MODULE : API RP 1102 Pipeline Local Pressure   ±

Calculate API RP 1102 local pipeline stationary internal pressure from elevation.

Elevation is measured relative to any arbitrary datum (+ve above the datum -ve below the datum). The internal fluid density is assumed constant. Use the Result Plot option to plot pressure versus elevation.

Reference : API RP 1102 : Steel Pipelines Crossing Railroads and Highways (2012)

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CALCULATOR MODULE : ASME B31.8 Gas Pipeline Flexibility And Stress Factor   ±
CALCULATOR MODULE : DNVGL RP-F101 Single Corrosion Defect   ±

Calculate DNVGL RP F101 allowable pressure for single corrosion defects.

Allowable pressure can be calculated for pressure load only for single longitudinal defects. For circumferential defects, or defects with compressive axial load use the combined pressure and compression load calculator. For circumferential defects the defect width is greater than the defect length. The allowable pressure can be calculated using either the calibrated safety factor (CSF) in section 3, or allowable stress design (ASD) in section 4. The system effect factor accounts for the measurement uncertainty when there are multiple defects of a similar size.

Reference : DNVGL-RP-F101 : Corroded Pipelines (Download from the DNVGL website)

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CALCULATOR MODULE : DNVGL RP F101 Local Incident Pressure   ±

Calculate DNVGL RP F101 local incident pressure and local external pressure from design pressure and elevation.

The local incident pressure is calculated from the design pressure and the elevation. Fluid density is assumed constant. Use the Result Plot option to plot local pressure and reference pressure versus elevation.

Reference : DNVGL-RP-F101 : Corroded Pipelines (Download from the DNVGL website)

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CALCULATOR MODULE : Flange Bolt Tensile Load   ±

Calculate flange bolt load, bolt stress and flange pressure.

The bolt load, bolt stress and flange pressure can be calculated from either the bolt design stress, a user defined bolt stress, a user defined bolt load, or a user defined flange pressure. The flange pressure is calculated with no gasket preload, or external loads such as bending moment. The bolt load equals the bolt stress times the tensile area. Tensile area is calculated for either ANSI or ISO threads. Bolt size can be calculated for either UNC, UNF, BSW or ISO bolts. The design stress can be calculated for either SAE, ISO or ASME bolt materials.

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Related Modules :

CALCULATOR MODULE : AS 2885.1 Pipeline Hydrotest Pressure   ±

Calculate AS 2885.1 pipeline test pressure and hoop stress check.

The required test pressure at the test point (the location where the test pressure is measured) is calculated from the local test pressure. The maximum test point pressure corresponds to the highest point on the pipeline. A test point pressure should be selected which is greater than or equal to the maximum calculated test point pressure, and the maximum hoop stress checked. For dry pipelines, the maximum hoop stress occurs at the lowest point on the pipeline. For wet pipeline sections, the maximum hoop stress occurs in the submerged section. Use the Result Plot option to plot the required test pressure versus elevation, or the hoop stress versus elevation for the selected test pressure. Hoop stress is calculated using Barlow's formula.

For the case where the local internal pressure is assumed to be equal to the maximum operating pressure at all points on the pipeline, use the user defined local pressure option, and set the internal pressure equal to the maximum operating pressure. This option is more onerous.

Note : A simplified check can be performed by calculating the maximum delta elevation from the maximum and minimum test pressure.

Reference : Australian Standard AS 2885.1 : Pipelines - Gas And Liquid Petroleum Part 1 : Design And Construction (2015)

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CALCULATOR MODULE : AS 2885.1 Pipeline Local Pressure   ±

Calculate AS 2885.1 pipeline local stationary pressure from elevation for dry and wet pipelines.

For dry pipelines external pressure is ignored. For wet pipelines the external pressure is included. The internal fluid density is assumed constant. Use the Result Plot option to plot pressure versus elevation.

Reference : Australian Standard AS 2885.1 : Pipelines - Gas And Liquid Petroleum Part 1 : Design And Construction (2015)

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CALCULATOR MODULE : AS 2885.1 Pipeline Design Pressure   ±

Calculate AS 2885.1 pipeline maximum allowable design pressure from pressure design wall thickness and allowable stress.

The maximum allowable design pressure is calculated so that the hoop stress equals the allowable stress. Use the Result Table option to table the allowable pressure versus wall thickness for the selected pipe diameter schedule.

Reference : Australian Standard AS 2885.1 : Pipelines - Gas And Liquid Petroleum Part 1 : Design And Construction (2015)

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CALCULATOR MODULE : AS 2885.1 Pipeline Collapse Pressure   ±
CALCULATOR MODULE : ASME B16.5 Pipe Flange Pressure Rating   ±

Calculate ASME B16.5 pipe flange rated pressure versus temperature (Table 2 SI values).

Rated pressure can be calculated by material group, or pipe flange class (class 150, 300, 400, 600, 900, 1500 and 2500). The rated pressure values are valid from -26 C, to the maximum data temperature. For temperatures greater than the maximum data temperature, the rated pressure can be calculated using either the constant value or constant slope option (these options should be used carefully - engineering judgment is required). Otherwise the rated pressure should be set to zero, as per the code. For temperatures below -26 C, addditional testing may be required (engineering judgment is required).

Use the Data Plot option to plot the rated pressure versus temperature for the selected material. Use the Data Table option to display the data table in the popup window (Table A-1 or K-1). Use the Result Table option to display a table of rated pressure versus material group or flange class. Change units on the setup page.

Reference : ANSI/ASME B16.5 : Pipe Flanges And Flanged Fittings (2017)

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CALCULATOR MODULE : Piping Fitting Minor Loss Factor   ±

Calculate pipe fitting minor loss factors.

Minor loss factors can be defined as:

  • Av (SI) flow coefficient - the flow in cubic meters per second fluid density 1 kilogram per cubic meter which gives a pressure drop of 1 Pa
  • Cv-uk (UK) flow coefficient - the flow in UK gallons per minute of water at 60 degrees F which gives a pressure drop of 1 psi
  • Cv-us (US) flow coefficient - the flow in US gallons per minute of water at 60 degrees F which gives a pressure drop of 1 psi
  • Cv-met (Metric) flow coefficient - the flow in liters per minute of water at 16 degrees C which gives a pressure drop of 1 bar
  • Kv (EU) flow coefficient - the flow in cubic meters per hour of water at 16 degrees C which gives a pressure drop of 1 bar
  • Cv* the dimensionless US flow factor = Cv-us / din^2 (din is the inside diameter in inches)
  • K factor - the ratio of pressure loss over the dynamic pressure
  • Cd or discharge coefficient - the ratio of the actual flow rate of the fluid through the fitting over the frictionless flow rate.

The K factor and discharge coefficient are dimensionless and can be used with any consistent set of units. The dimensionless flow coefficient has inconsistent units, and is unit specific. The flow coefficient Av, Cv-us, Cv-uk, Cv-met and Kv have dimensions length squared, and can not be used interchangeably between different systems of units.

Note : The friction factor K, discharge coefficient Cd, dimensionless flow coefficient Cv*, and flow coefficients Av, Cv-uk, Cv-us, Cv-met and Kv are used in different situations. The discharge coefficient is usually used for discharge through an orifice, but can also be used in other situations (for example pressure relief valves). The flow coefficients Av, Cv-uk, Cv-us, Cv-met and Kv, and the dimensionless flow coefficient Cv* are usually used for valves, but can also be used for other fittings. Engineering judgement is required to determine the correct minor loss factor to use.

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CALCULATOR MODULE : Piping Fitting Pressure Loss   ±

Calculate outlet pressure and pressure loss through piping and fittings.

The pressure loss is calculated from the Moody diagram using the Darcy-Weisbach friction factor. The Darcy friction factor can be calculated using either the Hagen-Poiseuille laminar flow equation, the original Colebrook White turbulent flow equation, or the modified Colebrook White equation. Changes in elevation are ignored.

For liquid piping with fittings the outlet pressure is calculated by:

`Po = P - 8 (fL/D+ΣK) ρ (Q^2) / (pi^2D^4) `
`ΔP = P - Po `

where :

ΔP = pressure loss
P =inlet pressure
Po = outlet pressure
Po = outlet pressure
ρ = fluid density
Q= fluid volume flowrate
f = Darcy friction factor
L = pipe length
D = pipe inside diameter
Σ K = total fitting K factor

For gas piping with fittings the outlet pressure is calculated by:

`Po = √(P^2 - 16m^2(fd.L / D + ΣK) (mma.SG.ZRoT)/(pi^2D^4) ) `

where :

m = gas mole flowrate
mma = air molar mass
SG = gas specific gravity
Z = gas compressibility factor
Ro = universal gas constant
T = gas temperature

For liquid fittings the outlet pressure is calculated by:

`Po = P - 8 K ρ (Q^2) / (pi^2D^4) `

where :

K = fitting K factor

For gas fittings the outlet pressure is calculated by:

`Po = √(P^2 - m^2K (16mma.SG.ZRoT)/(pi^2D^4) ) `

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CALCULATOR MODULE : Bernoulli's Equation Hydraulic Grade Line   ±

Calculate gas and liquid pipeline hydraulic pressure or hydraulic grade line (HGL) from data points using the Bernoulli equation.

The hydraulic or piezometric pressure is calculated by

`Ph = Ps + Pz `

where :

Ps = static pressure
Pz = potential or pressure
Ph = hydraulic or piezometric pressure (HGL)

For constant diameter pipelines, the friction pressure loss can be calculated from the difference in hydraulic pressure (changes in dynamic pressure are ignored). For gas pipelines, the changes in dynamic pressure are usually small compared to the other terms.

Note : The pressure terms are calculated at the selected data point. The data point option is set to pipe inlet when the page loads. Click calculate to update the data point options to include all of the data points before you select the data point. Click calculate each time you change the position data (X) values, and before you select the data point. Data points can be entered as comma separated values (Xi, Zi, Pi) with each set on a new line, or copy and paste from a spreadsheet.

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CALCULATOR MODULE : Bernoulli's Equation Energy Grade Line   ±

Calculate gas pipeline Bernoulli pressure or energy grade line (EGL) from data points using the Bernoulli equation.

The Bernoulli or total pressure (EGL) is calculated by

`Pb = Ps + Pd + Pz `
`Ph = Ps + Pz `

where :

Pb = Bernoulli pressure or total pressure (EGL)
Ps = static pressure
Pz = potential pressure
Pd = dynamic pressure
Ph = hydraulic or piezometric pressure (HGL)

For constant diameter pipelines, the friction pressure loss can be calculated from the difference in Bernoulli pressure. For gas pipelines, the changes in dynamic pressure are usually small compared to the other terms so that the hydraulic pressure (HGL) can also be used to calculate pressure loss.

Note : The pressure terms are calculated at the selected data point. The data point option is set to pipe inlet when the page loads. Click calculate to update the data point options to include all of the data points before you select the data point. Click calculate each time you change the position data (X) values, and before you select the data point. Data points can be entered as comma separated values (Xi, Zi, Pi) with each set on a new line, or copy and paste from a spreadsheet.

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CALCULATOR MODULE : Bernoulli's Equation Stationary Pressure From Elevation   ±

Calculate static pressure from elevation for gases and liquids using the Bernoulli equation.

For stationary fluid, the hydraulic or piezometric pressure is constant. The static pressure at any point can be calculated from a known pressure and relative elevation. For liquids, the fluid density is assumed to be constant. For gases, the fluid density varies with pressure.

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CALCULATOR MODULE : Liquid Pipeline Pressure Loss From The Darcy Weisbach Equation   ±

Calculate single phase liquid pipeline pressure loss using the Darcy Weisbach equation.

`Po = P - (fd L / (ID) + K) 1/2 ρ V^2 + ρ g (zi - zo) `

where :

Po = outlet pressure
P = inlet pressure
fd = Darcy friction factor
L = piping length
ID = piping inside diameter
K = total friction loss factor for fittings
ρ = fluid density
V = fluid velocity
g = gravity constant
zi = inlet elevation
zo = outlet elevation

The Darcy friction factor can be calculated for

  • Hagen-Poiseuille laminar flow equation
  • original Colebrook White equation
  • modified Colebrook White equation
  • Prandtl Nikuradse smooth pipe equation
  • Blasius smooth pipe equation
  • Colebrook smooth pipe equation
  • Miller smooth pipe equation
  • Konakov smooth pipe equation
  • Von Karman rough pipe equation

For low Reynolds numbers Re < 2000, the fluid flow is laminar and the Darcy friction factor should be calculated using the Hagen-Poiseuille laminar flow equation. For high Reynolds numbers Re > 4000, the fluid flow is turbulent and the Darcy friction factor should be calculated using one of the turbulent flow equations. In the transition region 2000 < Re < 4000, the flow is unstable and the friction loss cannot be reliably calculated. The minor loss K factor is used to account for pipeline fittings such as bends, tees, valves etc..

The calculators use the Darcy-Weisbach pressure loss equation. The Fanning friction factor is used with the Fanning pressure loss equation. The transmission factors are commonly used for gas flow. The results for the Darcy and Fanning equations are identical provided that the correct friction factor is used.

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CALCULATOR MODULE : Liquid Pipeline Pressure Loss From The Moody Diagram   ±

Calculate pressure loss for single phase liquid pipelines and ducts using the Darcy Weisbach version of the Moody Diagram.

`fdl = 64/(Re) `
`1/(√fdo) = -2 log10(r/3.7 + 2.51 / (Re √(fdo))) `
`1/(√fdm) = -2 log10(r/3.7 + 2.825 / (Re √(fdm))) `

where :

fdl = Hagen-Poiseuille laminar flow equation Darcy friction factor
fdo = original Colebrook White equation Darcy friction factor
fdm = modified Colebrook White equation Darcy friction factor
Re = Reynolds number
r = relative roughness

For low Reynolds numbers Re < 2000, the fluid flow is laminar and the Darcy friction factor should be calculated using the Hagen-Poiseuille laminar flow equation. For high Reynolds numbers Re > 4000, the fluid flow is turbulent and the Darcy friction factor should be calculated using one of the turbulent flow equations. In the transition region 2000 < Re < 4000, the flow is unstable and the friction loss cannot be reliably calculated. The minor loss K factor is used to account for pipeline fittings such as bends, tees, valves etc..

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CALCULATOR MODULE : Liquid Pipeline Pressure Loss From The AGA Equation   ±

Calculate pressure loss for single phase liquid pipelines using the AGA equation.

`Tr = 4 log(3.7 / (rr)) `
`Ts = 4 log((Re) / (Ts)) - 0.6 `
`Tt = 4 Df log((Re) / (1.4125 Ts)) `
`Tf = min(Tr, Tt) `
`fd = (2 / (Tf))^2 `

where :

Tr = rough pipe transmission factor
Ts = smooth pipe transmission factor
Tt = turbulent pipe transmission factor
Tf= Fanning transmission factor
fd = Darcy friction factor
rr = pipe relative roughness
Re = Reynolds number
Df = AGA drag factor

The AGA equation is used to calculate the Fanning transmission factor using an iteration method. Check that the convergence is close to or equal to one. The pressure loss is calculated from the Darcy friction factor using the Darcy-Weisbach equation. For low Reynolds numbers Re < 2000, the fluid flow is laminar and the Darcy friction factor should be calculated using the Hagen-Poiseuille laminar flow equation. For high Reynolds numbers Re > 4000, the fluid flow is turbulent and the Darcy friction factor should be calculated using the AGA equation. In the transition region 2000 < Re < 4000, the flow is unstable and the friction loss cannot be reliably calculated.

Pipe bends can be specified as either a bend angle, AGA bend index (degrees of bend per mile), or AGA drag factor. The drag factor is interpolated from the AGA table. The drag factor includes pipe roughness. Valves, tees and other pipe fittings should be included by adding a minor loss equivalent length to the pipeline length.

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CALCULATOR MODULE : Water Pipeline Pressure Loss From The Hazen Williams Equation   ±

Calculate pressure loss for single phase liquid pipelines using the Hazen Williams equation. For SI units

`Q = 0.85 c.A.rh^0.63 s^0.54 `
`rh = ID/4 `

where :

Q = flow rate
A = cross section area
ID = inside diameter
rh = hydraulic radius
s = channel slope
c = Hazen Williams friction factor

The Hazen Williams equation was developed for water pipes. Pipe roughness is accounted for using the Hazen Williams friction factor. The hydraulic radius is the ratio of pipe cross section area over pipe circumference (r/2 = ID/4). Valves, tees and other pipe fittings should be included by adding a minor loss equivalent length to the pipeline length.

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CALCULATOR MODULE : Water Open Channel Or Culvert Flow Rate From The Manning Equation   ±

Calculate flowrate in circular or rectangular water channels using the Manning equation.

`Q = A (rh^2)/3 s^(1/2) / n `
`rh = A/P `

where :

Q = flow rate
A = cross section area
P = wetted perimeter
rh = hydraulic radius
s = channel slope
n = Manning friction factor

The channel is assumed to be either open, or partly full and at ambient pressure. The head loss equals the change in elevation. Channel roughness is accounted for using the Manning friction factor. The hydraulic radius is the ratio of channel cross section area over the wetted perimeter. Valves, tees and other pipe fittings should be included by adding a minor loss equivalent length to the pipeline length.

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CALCULATOR MODULE : Liquid Pipeline Local Pressure   ±
CALCULATOR MODULE : Gas Pipeline Pressure Loss From The Darcy Weisbach Equation   ±

Calculate single phase gas pipeline pressure loss using the Darcy Weisbach equation.

`Po = √(P^2 - m^2(fd.L / D + K) ls (16mma.SG.ZRoT)/(pi^2D^4) ) / (es) `
`ss = (z2 - z2) SG.mma.g / (Ro T Z) `
`es = e^(ss) `
`ls = (es^2 - 1) / (ss) `

where :

Po = outlet pressure
P = inlet pressure
fd = Darcy friction factor
L = piping length
D = piping inside diameter
K = total friction loss factor for fittings
m = gas mole flowrategas
mma = air molar mass
SG = gas specific gravity
Z = gas compressibility factor
Ro = universal gas constant
T = gas temperature
g = gravity constant
zi = inlet elevation
zo = outlet elevation
ss = elevation exponent
es = elevation pressure factor
ls = elevation length factor

For low Reynolds numbers Re < 2000, the fluid flow is laminar and the Darcy friction factor should be calculated using the Hagen-Poiseuille laminar flow equation. For high Reynolds numbers Re > 4000, the fluid flow is turbulent and the Darcy friction factor should be calculated using one of the turbulent flow equations. In the transition region 2000 < Re < 4000, the flow is unstable and the friction loss cannot be reliably calculated. The minor loss K factor is used to account for pipeline fittings such as bends, tees, valves etc..

The calculators use the Darcy-Weisbach pressure loss equation with the Darcy friction factor. The Fanning transmission factor combined with the Fanning equation is commonly used for gas flow. The results for the Darcy and Fanning equations are identical provided that the correct friction factor is used.

The gas specific gravity is the ratio of gas density over the density of dry air at base temperature and pressure. The compressibility factor is assumed to equal 1 at the base conditions. The gas specific gravity is proportional to the gas molar mass.

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CALCULATOR MODULE : Gas Pipeline Pressure Loss From The Moody Diagram   ±

Calculate pressure loss for single phase gas pipelines using the Darcy Weisbach version of the Moody Diagram.

`fdl = 64/(Re) `
`1/(√fdo) = -2 log10(r/3.7 + 2.51 / (Re √(fdo))) `
`1/(√fdm) = -2 log10(r/3.7 + 2.825 / (Re √(fdm))) `

where :

fdl = Hagen-Poiseuille laminar flow equation Darcy friction factor
fdo = original Colebrook White equation Darcy friction factor
fdm = modified Colebrook White equation Darcy friction factor
Re = Reynolds number
r = relative roughness

For low Reynolds numbers Re < 2000, the fluid flow is laminar and the Darcy friction factor should be calculated using the Hagen-Poiseuille laminar flow equation. For high Reynolds numbers Re > 4000, the fluid flow is turbulent and the Darcy friction factor should be calculated using one of the turbulent flow equations. In the transition region 2000 < Re < 4000, the flow is unstable and the friction loss cannot be reliably calculated. The minor loss K factor is used to account for pipeline fittings such as bends, tees, valves etc..

The calculators use the Darcy-Weisbach version of the Moody diagram. The Fanning transmission factor combined with the Fanning equation is commonly used for gas flow. The results for the Darcy and Fanning equations are identical provided that the correct friction factor is used.

`ff = (fd) / 4 `
`tf = 1 / (√ff)= 2 / (√fd) `

where :

fd = Darcy friction factor
ff = Fanning friction factor
tf = Fanning transmission factor

The gas specific gravity is the ratio of gas density over the density of dry air at base temperature and pressure. The compressibility factor is assumed to equal 1 at the base conditions. The gas specific gravity is proportional to the gas molar mass.

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CALCULATOR MODULE : Gas Pipeline Pressure Loss From The AGA Equation   ±

Calculate pressure loss for single phase gas pipelines using the AGA equation.

`Tr = 4 log(3.7 / (rr)) `
`Ts = 4 log((Re) / (Ts)) - 0.6 `
`Tt = 4 Df log((Re) / (1.4125 Ts)) `
`Tf = min(Tr, Tt) `
`fd = (2 / (Tf))^2 `

where :

Tr = rough pipe transmission factor
Ts = smooth pipe transmission factor
Tt = turbulent pipe transmission factor
Tf= Fanning transmission factor
fd = Darcy friction factor
rr = pipe relative roughness
Re = Reynolds number
Df = AGA drag factor

The AGA equation is used to calculate the Fanning transmission factor using an iteration method. Check that the convergence is close to or equal to one. The pressure loss is calculated from the Darcy friction factor using the Darcy-Weisbach equation. For low Reynolds numbers Re < 2000, the fluid flow is laminar and the Darcy friction factor should be calculated using the Hagen-Poiseuille laminar flow equation. For high Reynolds numbers Re > 4000, the fluid flow is turbulent and the Darcy friction factor should be calculated using the AGA equation. In the transition region 2000 < Re < 4000, the flow is unstable and the friction loss cannot be reliably calculated.

Pipe bends can be specified as either a bend angle, AGA bend index (degrees of bend per mile), or AGA drag factor. The drag factor is interpolated from the AGA table. The drag factor includes pipe roughness. Valves, tees and other pipe fittings should be included by adding a minor loss equivalent length to the pipeline length.

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CALCULATOR MODULE : Gas Pipeline Pressure Loss From The Weymouth And Panhandle Equation   ±

Calculate pressure loss for single phase gas pipelines using either the Weymouth equation, the Panhandle A equation, the Panhandle B equation, or the general equation (user defined Darcy friction factor).

`Q = 77.57 ((Tb) / (Pb)) ((P^2 - ess. Po^2) / (SG .T. L. ls Z. fd))^0.5 D^2.5 `General ` `
`Q = 433.5 ((Tb) / (Pb)) E ((P^2 - ess. Po^2) / (SG .T. L. ls. Z))^0.5 D^2.667 `Weymouth` `
`Q = 437.87 ((Tb) / (Pb))^1.0788 E ((P^2 - ess. Po^2) / (SG^0.8539. T .L. ls. Z))^0.5394 D^2.6182 `Panhandle A` `
`Q = 738.73 ((Tb) / (Pb))^1.02 E ((P^2 - ess. Po^2) / (SG^0.961. T. L. ls. Z))^0.51 D^2.53 `Panhandle B` `
`ss = (z2 - z2) SG. mma. g / (Ro T Z) `
`es = exp(ss) `
`ls = (es^2 - 1) / (ss) `

where :

Q = mole flowrate (SCFD)
Po = outlet pressure (psia)
P = inlet pressure (psia)
Tb = base temperature (60 F)
Pb = base pressure (1 atm)
fd = Darcy friction factor
E = efficiency factor
L = piping length (mi)
D = piping inside diameter (in)
K = total friction loss factor for fittings
g = gravity constant
zi = inlet elevation
zo = outlet elevation
ss = elevation exponent
es = elevation pressure factor
ls = elevation length factor

Pipe roughness can be accounted for using the efficiency factor. Minor losses such as bends, valves, tees and other pipe fittings should be included by adding a minor loss equivalent length to the pipeline length. The calculations are not suitable for laminar flow.

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Related Modules :

CALCULATOR MODULE : Gas Pipeline Line Pack   ±
CALCULATOR MODULE : Low Pressure Air Pressure Loss From The Moody Diagram   ±

Calculate pressure loss for low pressure air circular and rectangular ducts using the Moody diagram.

The calculators use the Darcy-Weisbach pressure loss equation. For low Reynolds numbers Re < 2000, the fluid flow is laminar and the Darcy friction factor should be calculated using the Hagen-Poiseuille laminar flow equation. For high Reynolds numbers Re > 4000, the fluid flow is turbulent and the Darcy friction factor should be calculated using one of the turbulent flow equations. In the transition region 2000 < Re < 4000, the flow is unstable and the friction loss cannot be reliably calculated.

Minor losses can be entered as either a K friction factor, a length, or length over diameter ratio. The minor losses are used to account for pipeline fittings such as bends, tees, valves etc.. :sg:For air the gas specific gravity SG = 1.0. For low pressure air the compressibility factor is assumed equal to one.

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CALCULATOR MODULE : Gas Pipeline Local Pressure   ±
CALCULATOR MODULE : API RP 14E General Gas Piping Pressure Loss Equation   ±

Calculate API RP 14E gas piping pressure loss from the general equation.

The pressure loss is calculated using the Darcy-Weisbach form of the Moody diagram. For low Reynolds numbers Re < 2000, the fluid flow is laminar and the Hagen-Poiseuille laminar flow option should be used. In the transition region 2000 < Re < 4000, the flow is unstable and cannot be reliably calculated. For turbulent flow (Re > 4000), either the original Colebrook White equation or the modified Colebrook White equation can be used. Minor losses are used to account for pipeline fittings such as bends, tees, valves etc.

Reference : API 14E Recommended Practice For Design and Installation of Offshore Production Platform Piping Systems

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CALCULATOR MODULE : API RP 14E Weymouth Gas Piping Pressure Loss Equation   ±

Calculate API RP 14E gas piping pressure loss from the Weymouth equation.

The Weymouth equation was developed for fully developed turbulent flow in long pipelines. It is not suitable for low Reynolds number, or short piping sections. Minor losses are used to account for pipeline fittings such as bends, tees, valves etc. Compare the results for the Weymouth equation, the general equation (Moody diagram), and the Panhandle A and B equations.

Reference : API 14E Recommended Practice For Design and Installation of Offshore Production Platform Piping Systems

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CALCULATOR MODULE : API RP 14E Panhandle Gas Piping Pressure Loss Equation   ±

Calculate API RP 14E gas piping pressure loss from the Panhandle equation.

The Panhandle equations were developed for fully developed turbulent flow in long pipelines. They are not suitable for low Reynolds number, or short piping sections. Minor losses are used to account for pipeline fittings such as bends, tees, valves etc. Compare the results for the Weymouth equation, the general equation (Moody diagram), and the Panhandle A and B equations.

Reference : API 14E Recommended Practice For Design and Installation of Offshore Production Platform Piping Systems

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CALCULATOR MODULE : API RP 14E Liquid Piping Pressure Loss Equation   ±

Calculate API RP 14E liquid piping pressure loss from the Moody diagram.

The pressure loss is calculated using the Darcy-Weisbach form of the Moody diagram. For low Reynolds numbers Re < 2000, the fluid flow is laminar and the Hagen-Poiseuille laminar flow option should be used. In the transition region 2000 < Re < 4000, the flow is unstable and cannot be reliably calculated. For turbulent flow (Re > 4000), either the original Colebrook White equation or the modified Colebrook White equation can be used. Minor losses are used to account for pipeline fittings such as bends, tees, valves etc.

Reference : API 14E Recommended Practice For Design and Installation of Offshore Production Platform Piping Systems

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CALCULATOR MODULE : Pipeline Flow Rate   ±
CALCULATOR MODULE : Compressible Flow Blowdown Time   ±

Calculate compressible flow pipeline or vessel blow down time through a constant diameter vent for adiabatic and isothermal flow using either the integration method, or the simplified method.

The integration method uses numerical integration to calculate the elapsed time between the initial pressure, and the final blow down pressure. At high pressure the vent exit flow is critical (Mc = 1 for adiabatic flow and 1/√γ for isothermal flow). At lower pressures the vent exit flow is sub critical (M < Mc). The vent entry is subsonic at all conditions. Increase the number of steps to improve the accuracy. Use the minimum number of steps required (the method is reasonably accurate with 16 steps). Using a large number of steps may slow down the calculation, especially on older computers. The accuracy of the integration method decreases at pressure less than 1.1 x ambient pressure (ie 110 kPa or 16.2 psi for atmospheric pressure discharge). The blow down time tends to infinity as the final pressure approaches ambient pressure.

The simplified method calculates the blow down time from the initial pipeline gas moles, and the initial vent mole flow rate. The flow is assumed to be always critical, and the pipeline pressure is assumed to decrease exponentially. The simplified method is reasonably accurate for final pressure ≥ 2 x ambient pressure. At low pressures flow is sub critical and the simplified method underestimates the elapsed time relative to the integration method (both methods are less accurate at very low pressure). The simplified method is not recommended for final pressure less than 1.2 x ambient pressure. The blow down time tends to infinity as the final pressure approaches absolute zero.

Minor losses should include the vent entry valves and bends etc. The vent exit should not be included as the fluid dynamic pressure is included in the calculation. Minor losses can be accounted for by using the minor loss factor K, or the discharge coefficient Cd. The discharge coefficient is used to factor the mole flow rate. The gas in the pipeline is assumed to be stationary (stagnation conditions), ie the pipeline diameter >> the vent diameter. Phase changes are ignored. The Darcy friction factor is calculated from pipe roughness assuming fully turbulent flow.

Note : The final blow down pressure should be above ambient pressure (final blow down pressure ≤ ambient pressure causes a divide by zero error).

Reference : Fluid Mechanics, Frank M White, McGraw Hill

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CALCULATOR MODULE : Compressible Flow Pressure Relief Vent   ±

Calculate compressible flow pressure relief vent flow rate and pressure drop for either adiabatic or isothermal flow.

The vent is modelled as a frictionless entry, combined with a frictional constant diameter duct. For adiabatic flow the vent entry is assumed to be isentropic. For isothermal flow, the vent entry is assumed to be isothermal. The vent entry is assumed to be subsonic at all conditions. The pipeline is assumed to be at stagnation conditions (M = 0). At high pressure the vent exit flow is critical flow (Mc = 1 for adiabatic low and `Mc = 1 / (√γ)` for isothermal flow : γ = the gas specific heat ratio). At lower pressures the vent exit flow is sub critical (M < Mc).

Vent flow rate is calculated from the vent pressure loss factor (fld).

`fld = fd L/D + K `

where :

fld = vent pressure loss factor
fd = Darcy friction factor
L = vent length
D = vent inside diameter
K = minor loss K factor

The Darcy friction factor is calculated assuming fully turbulent flow. Minor losses should include the vent entry, and valves, bends etc.. The vent exit should not be included (the fluid dynamic pressure is included in the calculation). The discharge coefficient can be used as a safety factor.

Note : The vent calculation is not suitable for pressure relief headers which are part of a pressure relief valve (PRV) system.

Use the Result Plot option to plot inlet and exit pressure versus stagnation pressure, inlet and exit mach number versus stagnation pressure, or mass flow rate versus stagnation pressure and flow type.

Reference : Fluid Mechanics, Frank M White, McGraw Hill

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CALCULATOR MODULE : Compressible Flow Pressure Loss Factor   ±
CALCULATOR MODULE : DNVGL RP F115 Pipeline Pre Commissioning   ±
CALCULATOR MODULE : DNVGL RP F115 Pipeline Test Pressure   ±

Calculate DNVGL RP-F115 pipeline test pressure from design pressure and elevation.

The system test pressure is calculated from the local incidental pressure. The required system test pressure and mill test pressure should be calculated for all points on the pipeline or pipeline section. Use the Result Plot option to plot the test pressure and hoop stress from minimum to maximum elevation.

Reference : DNVGL-RP-F115 Pre-commissioning of Submarine Pipelines (Download from the DNVGL website)

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CALCULATOR MODULE : DNVGL RP F115 Pipeline Pressure Response   ±
CALCULATOR MODULE : DNVGL RP F115 Pipeline Temperature Correction   ±
CALCULATOR MODULE : DNVGL RP F115 Pipeline Tidal Correction   ±
CALCULATOR MODULE : DNVGL RP F115 Pipeline Local Pressure   ±

Calculate DNVGL RP-F115 pipeline local stationary internal and external pressure from elevation.

The external pressure is calculated from the water depth. The internal fluid density is assumed constant. Elevation is measured relative to any arbitrary datum (+ve above the datum -ve below the datum). Use the Result Plot option to plot pressure versus elevation.

Reference : DNVGL-RP-F115 Pre-commissioning of Submarine Pipelines (Download from the DNVGL website)

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CALCULATOR MODULE : API 520 Pressure Relief Device   ±
CALCULATOR MODULE : API 520 Gas Pressure Relief Valve   ±

Calculate API 520 gas pressure relief valve (PRV) and rupture disk size.

The flow through the relief valve nozzle is assumed to be sonic (M = 1), adiabatic, and isentropic. If the back pressure is greater than the critical (sonic) pressure the flow is subsonic (M < 1).

Friction losses are accounted for using the discharge coefficient Kd. For initial sizing of PRV's the effective nozzle diameter should be used with the discharge coefficient Kd = 0.975. The actual nozzle diameter and the rated coefficient of discharge should be used to verify that the selected PRV is suitable for the required flow rate. The PRV effective diameter is taken from API 526 (letter designation D to T). Changes in phase are not accounted for.

The calculation can also be used for rupture disks. The rupture disk diameter should be substituted for the nozzle diameter, with a discharge coefficient Kd = 0.62. Rupture disks can also be analysed as part of a relief vent system using the flow resistance method.

Note : The ideal gas calculators use the ideal gas compressible flow equations. The API 520 gas and steam calculations use an approximation of the ideal gas compressible flow equations. Use the ideal gas calculators for a comparison with the API 520 calculators.

Reference : API 520 Sizing, Selection And Installation Of Pressure Relieving Devices (2014)

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CALCULATOR MODULE : API 520 Steam Pressure Relief Valve   ±

Calculate API 520 steam pressure relief valve (PRV) and rupture disk size.

The flow through the relief valve nozzle is analysed using the Napier equation. For temperatures above 1200 F (922 K), the gas PRV calculation should be used. If the back pressure is greater than the critical (sonic) pressure the flow is sub sonic (M < 1).

Friction losses are accounted for using the discharge coefficient Kd. For initial sizing of PRV's the effective nozzle diameter should be used with the discharge coefficient Kd = 0.975. The actual nozzle diameter and rated coefficient of discharge should be used to verify that the selected PRV is suitable for the required flow rate. The PRV effective diameter is taken from API 526 (letter designation D to T). Changes in phase are not accounted for.

The calculation can also be used for rupture disks. The rupture disk diameter should be substituted for the nozzle diameter, with a discharge coefficient Kd = 0.62. Rupture disks can also be analysed as part of a relief vent system using the flow resistance method.

Note : The ideal gas calculators use the ideal gas compressible flow equations. The API 520 gas and steam calculations use an approximation of the ideal gas compressible flow equations. Use the ideal gas calculators for a comparison with the API 520 calculators.

Reference : API 520 Sizing, Selection And Installation Of Pressure Relieving Devices (2014)

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CALCULATOR MODULE : API 520 Liquid Pressure Relief Valve   ±

Calculate API 520 liquid pressure relief valve (PRV) and rupture disk size (certified and non certifed devices).

The flow through the relief valve nozzle is analysed using the Bernoulli equation. Friction losses are accounted for using the discharge coefficient Kd. For initial sizing of PRV's the effective nozzle diameter should be used with the discharge coefficient Kd = 0.65 for certified PRV's and Kd = 0.62 for non certified PRV's. The actual nozzle diameter and rated coefficient of discharge should be used to verify that the selected PRV is suitable for the required flow rate. The PRV effective diameter is taken from API 526 (letter designation D to T). Changes in phase are not accounted for.

The PRV calculation can also be used for rupture disks. The rupture disk diameter should be substituted for the nozzle diameter, with a discharge coefficient Kd = 0.62. Rupture disks can also be analysed as part of a relief vent system using the flow resistance method.

Reference : API 520 Sizing, Selection And Installation Of Pressure Relieving Devices (2014)

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CALCULATOR MODULE : API 520 Correction Factor   ±
CALCULATOR MODULE : API 520 Critical Flow Ratio   ±
CALCULATOR MODULE : API 520 Pressure Relief Vent   ±

Calculate API 520 flow rate through a constant diameter pressure relief vent.

The vent entry is assumed to be a pressure vessel or piping at stagnation pressure (valid when the pipe or vessel diameter is much greater than the vent diameter). The calculated vent exit pressure is flowing pressure (stagnation pressure minus dynamic pressure).

Vent pressure losses are calculated from the vent pressure loss factor (fld = fL/D + K). Minor losses should include the vent entry, valves and bends etc. The vent exit should not be included. The discharge coefficient can be used to factor the flow rate, depending on the design requirements.

For rupture disks, the flow resistance factor of the rupture Kr should be included in the minor losses (the resistance factor should be factored for the vent diameter). A discharge coefficient of 0.9 or less should be used for rupture disks. Alternatively, the PRV calculators can be used for rupture disk calculations.

Note : The ideal gas calculators use the ideal gas compressible flow equations. The API 520 gas and steam calculations use an approximation of the ideal gas compressible flow equations. Use the ideal gas calculators for a comparison with the API 520 calculators.

Reference : API 520 Sizing, Selection And Installation Of Pressure Relieving Devices (2014)

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CALCULATOR MODULE : API 520 Back Pressure   ±

Calculate API 520 back pressure from mass flow rate through a constant diameter vent.

The calculated vent entry and exit pressures are flowing pressure (stagnation pressure minus dynamic pressure). Minor losses should include bends and valves etc. The vent entry and exit should not be included in the minor losses. The discharge coefficient can be used to factor the mass flow rate, depending on design requirements.

Where multiple pressure relieving devices share a common vent, the back pressure should be calculated for the total mass flow rate.

For relief vents with sections of increasing diameter, the back pressure should be calculated for each constant diameter section, going backwards from exit. The (flowing) exit pressure for each section equals the (flowing) inlet pressure for the previous section.

For pressure relief valves or rupture disks, the (flowing) inlet pressure for the vent is used as the (flowing) back pressure for the pressure relief device. This is valid provided that the vent diameter is greater than the diamter of the PRV nozzle or rupture disk.

Note : The ideal gas calculators use the ideal gas compressible flow equations. The API 520 gas and steam calculations use an approximation of the ideal gas compressible flow equations. Use the ideal gas calculators for a comparison with the API 520 calculators.

Reference : API 520 Sizing, Selection And Installation Of Pressure Relieving Devices (2014)

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CALCULATOR MODULE : Water Hammer Transient Pressure   ±

Calculate water hammer transient pressure and pressure wave velocity.

Water hammer is caused by a sudden reduction of flow rate in liquid pipelines. Water hammer commonly occurs in water pipes, but it can occur in any liquid piping system. The transient pressure is reduced if gas is present in the liquid, or if the effective shut off time is greater than the maximum shut off time. The maximum shut off time is the time taken for the pressure transient to travel to the pipe inlet, and back again.

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CALCULATOR MODULE : Transient Pressure Wave Velocity   ±

Calculate water hammer transient pressure wave velocity.

A sudden reduction of velocity in a liquid pipeline initiates a pressure wave which travels to the pipe inlet, and then back. The wave velocity increases with pipe stiffness. Any gas present in the liquid reduces the pressure wave velocity. The maximum shut off time is the time taken for the pressure transient to travel to the pipe inlet, and back again.

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CALCULATOR MODULE : Tank Or Pressure Vessel Piping Volume   ±

Calculate the fluid volume and mass for tank and vessel piping.

Fluid volume and mass can be calculated for liquid piping, gas piping, two phase gas and liquid piping, or three phase gas, water and oil (black oil). The piping is assumed to be full and mixed (ie flowing).

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DATA MODULE : ASME B31 Pipe And Flange Dimension ( Open In Popup Workbook )   ±

ASME B31.8 gas pipe and flange data values: pipe dimensions, flange dimensions, cover requirements, cold bends, burn through and location class.

Reference : ANSI/ASME B31.8 : Gas Transmission And Distribution Piping Systems

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    DATA MODULE : ASME B31.3 Process Piping Plastic Component ( Open In Popup Workbook )   ±
    DATA MODULE : ASME B16.5 Pipe Flange Pressure Rating ( Open In Popup Workbook )   ±

    ASME B16.5 pipe flange rated pressure versus temperature for class 150, 300, 400, 600, 900, 1500 and 2500 (Table 2 SI values).

    Use the ASME B16.5 rated pressure calculators (see link below) to interpolate the data values, or to convert the data values to other units.

    Reference : ANSI/ASME B16.5 : Pipe Flanges And Flanged Fittings (2017)

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