ASME B31.3 Process Piping Plastic Component

Calculate pipe wall thickness for pressure containment for low pressure plastic pipe (ASME B31.3 section A304.1).

Pipe wall thickness can be calculated from either the outside diameter (constant OD pipe), or the inside diameter (constant ID pipe). All user defined tolerances should be positive. The corrosion allowance should include mechanical allowance (eg threads), erosion allowance and any other allowances.

Tool Input

• schdtype : Pipe Schedule Type
• diamtype : Diameter Type
  • ODu : User Defined Outside Diameter
  • IDu : User Defined Inside Diameter
• wtntype : Wall Thickness Type
  • tnu : User Defined Wall Thickness
  • DRu : User Defined Dimension Ratio SDR OR SIDR
• ttoltype : Wall Thickness Tolerance Type
  • xfu : User Defined Negative Wall Thickness Fraction
  • tfu : User Defined Negative Wall Thickness Allowance
• mattype : Design Stress Type (23 C)
  • HDSu : User Defined Hydraulic Design Stress
• walltype : Wall Thickness Calculation Type
• c : Mechanical Allowance
• P : Fluid Pressure

Tool Output

• CVG : Convergence Factor
• DR : Dimension Ratio (SDR or SIDR)
• HDS : Hydrostatic Design Stress Table B-1
• ID : Pipe Inside Diameter
• OD : Pipe Outside Diameter
• PR : Design Pressure
• Sh : Hoop Stress (≤ HDS)
• Sh/Sd : Hoop Stress Over Design Stress Ratio (≤ 1)
• tf : Wall Thickness Fabrication Allowance
• th : Pressure Design Wall Thickness
• tm : Minimum Wall Thickness
• tn : Nominal Wall Thickness
• xf : Wall Thickness Fabrication Fraction

Calculate test pressure and hoop stress for low pressure plastic pipe (ASME B31.3 section A345).

For hydrotest the test factor = 1.5. The R factor is required if the allowable stress at the test temperature is greater than the allowable stress at the design temperature. The R factor is the ratio of allowable stress at the test temperature over the allowable stress at the design temperature. The test pressure should be less than or equal to 1.5 x the rated pressure of the lowest rated component in the system.

For pneumatic test the test factor = 1.1. The test pressure should be less than or equal to 1.33 x the design pressure, and less than or equal to 1.35 x the rated pressure for components.

Tool Input

• schdtype : Pipe Schedule Type
• diamtype : Diameter Type
  • ODu : User Defined Outside Diameter
  • IDu : User Defined Inside Diameter
• wtntype : Wall Thickness Type
  • tnu : User Defined Wall Thickness
  • DRu : User Defined Dimension Ratio SDR OR SIDR
• ttoltype : Wall Thickness Tolerance Type
  • xfu : User Defined Negative Wall Thickness Fraction
  • tfu : User Defined Negative Wall Thickness Allowance
• walltype : Hoop Stress Wall Thickness Type
• rfactype : R Factor Type
  • St : User Defined Hydrostatic Design Stress At Test Temperature
  • S : User Defined Hydrostatic Design Stress At Design Temperature
  • Ru : User Defined R Factor
• testtype : Test Pressure Type
  • Pru : User Defined Component Rated Pressure
  • Ptu : User Defined Test Pressure
  • Tu : User Defined Test Pressure Factor
• c : Mechanical Allowance
• P : Design Pressure
• HDB : Hydrostatic Design Basis At Test Temperature

Tool Output

• CVG : Convergence Factor
• DR : Dimension Ratio (SDR or SIDR)
• ID : Pipe Inside Diameter
• OD : Pipe Outside Diameter
• Pt : Test Pressure
• Pt/P : Test Pressure Over Design Pressure Ratio
• Py : Yield Pressure
• R : R Factor St/S
• Sh : Hoop Stress [ Pa ]
• Sh/HDB : Hoop Stress Over HDB Ratio (≤ 1)
• T : Test Pressure Factor
• t* : Wall Thickness For Hoop Stress Calculation
• tf : Wall Thickness Fabrication Allowance
• th : Pressure Containment Wall Thickness
• tm : Minimum Wall Thickness
• tn : Nominal Wall Thickness

Calculate ASME B31.3 plastic pipe unit mass and total mass from pipe schedule or user defined pipe diameter and either wall thickness or dimension ratio.

Select the pipe schedule (NPS or ISO), pipe diameter and wall thickness, or use the user defined option. Use the Result Table option to display the pipe schedule with unit mass and total mass for the selected diameter. The dimension ratio (SDR or SIDR) is calculated from the pressure design thickness (nominal wall thickness minus fabrication allowance and mechanical allowance).

Tool Input

• schdtype : Schedule Type
• diamtype : Diameter Type
  • ODu : User Defined Outside Diameter
  • IDu : User Defined Inside Diameter
• wtntype : Wall Thickness Type
  • tnu : User Defined Wall Thickness
  • DRu : User Defined Dimension Ratio SDR OR SIDR
• ttoltype : Wall Thickness Fabrication Tolerance Type
  • xfu : User Defined Negative Wall Thickness Fraction
  • tfu : User Defined Negative Wall Thickness Allowance
• modptype : Material Property Type
  • ρpu : User Defined Pipe Density
• c : Wall Thickness Mechanical Allowance
• L : Pipe Length

Tool Output

• ρp : Pipe Density
• CVG : Convergence Factor
• DR : Pipe Dimension Ratio (SDR Or SIDR)
• ID : Nominal Inside Diameter
• M : Pipe Total Mass
• OD : Nominal Outside Diameter
• m : Pipe Mass Per Length
• tf : Wall Thickness Fabrication Allowance
• tm : Minimum Wall Thickness
• tn : Nominal Wall Thickness
• tp : Pressure Design Wall Thickness