Dear all,
I will soon have to start learning Pipe Stress Analysis in order to be able to perform such calculations for my company. We are water treatment plant producers and we work mainly with thermoplastic materials (PVDF, PP).
The preliminary step for me is to have an overview of which are the applicable design codes that are involved in the calculations (e.g to compute stresses in the pipes, evaluate allowable stresses, ...).
I started by reading ASME B31.3 but in chapter VII it is clearly written that elastic behaviour assumptions (stress proportional to strain) in a wide range of strains is not generally valid. Additionally it seems that this chapter doesn't cover thermoplastic materials with a mathematical approach as extensively as it does for metals.
I have also seen that ASME has released some other design codes ASME NM.1, NM. 3.1, NM. 3.2, NM 3.3 which cover more in detail thermoplastic materials.
My questions are the following:
1) Is ASME B31.3 applicable for the thermoplastic materials I have mentioned?
2) I have found a calculation for PP pipes that was done in Autopipe. The design codes mentioned were ASME B31.3 and ASME B31J for intensification factors. From ASME B31.3 it seemed to use eq. 23a (320.2 Stress Due to Sustained load) which comes from the chapters relevant to metals. Is this approach acceptable given the piping is thermoplastic?
3) Are ASME NM codes "more applicable" than ASME B31.3 for thermoplastics? Or are they complementary to it?
Thank you all for your time
I will soon have to start learning Pipe Stress Analysis in order to be able to perform such calculations for my company. We are water treatment plant producers and we work mainly with thermoplastic materials (PVDF, PP).
The preliminary step for me is to have an overview of which are the applicable design codes that are involved in the calculations (e.g to compute stresses in the pipes, evaluate allowable stresses, ...).
I started by reading ASME B31.3 but in chapter VII it is clearly written that elastic behaviour assumptions (stress proportional to strain) in a wide range of strains is not generally valid. Additionally it seems that this chapter doesn't cover thermoplastic materials with a mathematical approach as extensively as it does for metals.
I have also seen that ASME has released some other design codes ASME NM.1, NM. 3.1, NM. 3.2, NM 3.3 which cover more in detail thermoplastic materials.
My questions are the following:
1) Is ASME B31.3 applicable for the thermoplastic materials I have mentioned?
2) I have found a calculation for PP pipes that was done in Autopipe. The design codes mentioned were ASME B31.3 and ASME B31J for intensification factors. From ASME B31.3 it seemed to use eq. 23a (320.2 Stress Due to Sustained load) which comes from the chapters relevant to metals. Is this approach acceptable given the piping is thermoplastic?
3) Are ASME NM codes "more applicable" than ASME B31.3 for thermoplastics? Or are they complementary to it?
Thank you all for your time
