ASME Allowable Stress - Safety Factors
ASME Allowable Stress - Safety Factors
(OP)
B31.4 clearly states use of safety factor of .72.
For B31.3, we use .5 and .6, but I cannot locate references to these factors in the code. Do you know where they are referenced and shown?
For B31.3, we use .5 and .6, but I cannot locate references to these factors in the code. Do you know where they are referenced and shown?





RE: ASME Allowable Stress - Safety Factors
RE: ASME Allowable Stress - Safety Factors
For B31.3 we use .5, .6, or can use .72 with engineer approval. But I do not see a similar reference in 31.3 to the 402.3 ref in 31.4 that show where .5 or .6 are stated or how to apply. I would appreciate your thoughts. Thanks!
RE: ASME Allowable Stress - Safety Factors
B31.3 has no corresponding "Area Class Factor" and allowable stresses are defined for each material. For example, you will find the method for determination of thickness required for designing a pipe component under B31.3 in Par 304.1.1 under the definition of "S", for which you are referred to Table A-1 for specific values for various materials.
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: ASME Allowable Stress - Safety Factors
"B31.3 we use .5, .6, or can use .72 with engineer approval"
You should not be using Class Factors for B31.3 designs.
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: ASME Allowable Stress - Safety Factors