Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

ASME 31.3 Allowable Pressure Calculator

Calculate ASME 31.3 allowable pressure

Sponsored Links

The ASME code B31.3 recommends allowable tensile stress levels in pipe materials. The equations used in B31.3 are

t = P D / (2 (S E + P Y)                    (1)

where

t = thickness of pipe (in)

P = internal pressure in pipe (psi)

D = outside diameter of pipe (in)

S = allowable tensile stress (psi)

E = quality factor for the piping according ASME 31.3

Y = wall thickness coefficient according ASME 31.3 (y = 0.5 for thin pipes and y < 0.5 for thick pipes)

or

t = P (d + 2 c) / (2 (S E + P (1 - Y))                    (2)

where

d = inside diameter of pipe (in)

c = sum of the mechanical allowances (thread or groove depth) plus corrosion and erosion allowances (in) - typical 0.02 in where tolerances are not specified

Eq. (1) can be rearranged to express allowable internal piping pressure as

p = 2 t S E / (D - 2 t Y)                      (1b)

Example - Allowable Pressure in a Steel Pipe

The allowable pressure in a 4 inch schedule 40 carbon steel pipe with outside diameter 4.5 in, wall thickness 0.237 in and allowable stress 16000 psi, can with quality factor E for steel 0.8 and wall thickness coefficient 0.4 be calculated as

p = 2 (0.237 in) (16000 psi) (0.8) / ((4.5 in) - 2 (0.237) 0.4)

   = 1408 psi      

ASME 31.3 Allowable Pressure Calculator (from eq. 1b)

t - thickness of pipe (in)

S - allowable tensile stress (psi)

E - quality factor for piping material

D - outside pipe diameter (in)

Y - wall thickness coefficient

Quality Factors E

Some quality factors according ASME 31.3:

  • furnace butt weld joint, continuous weld joint, straight seam: 0.6
  • electrical resistance weld joint, straight or spiral seam: 0.85  
  • double butt weld joint, straight or spiral seam, 100% radiographed: 1.0

Thickness Coefficients Y

The values of coefficient Y depends on type of material, temperature and thickness limits.

Thickness coefficients when t > D / 6:

Y = (d + 2 c) / (D + d + 2 c)                  (3)

Thickness coefficients when t < D / 6:

Coefficient Y
MaterialTemperature (oF)
< 900950100010501100> 1150
Ferritic steels 0.4 0.5 0.7 0.7 0.7 0.7
Autenitic steel 0.4 0.4 0.4 0.4 0.5 0.7
Other ductile materials 0.4 0.4 0.4 0.4 0.4
Cast iron 0.0
Sponsored Links

Related Topics

Related Documents

Tag Search

  • en: asme 31.3 piping pressure calculations operating burst
Sponsored Links

Search the Engineering ToolBox

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro .Add the Engineering ToolBox extension to your SketchUp from the SketchUp Pro Sketchup Extension Warehouse!

Translate this page to
About the Engineering ToolBox!

Privacy

We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.

Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

Google use cookies for serving our ads and handling visitor statistics. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected.

AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information.

Citation

This page can be cited as

  • Engineering ToolBox, (2019). ASME 31.3 Allowable Pressure Calculator. [online] Available at: https://www.engineeringtoolbox.com/asme-31.3-piping-pressure-calculations-d_2158.html [Accessed Day Mo. Year].

Modify access date.

. .

close

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Scientific Online Calculator

Scientific Calculator

9 13

Sponsored Links
.