PIPE FLATTENING TEST ACCEPTANCE PER ASME A530
PIPE FLATTENING TEST ACCEPTANCE PER ASME A530
(OP)
I am looking for testimonials from test labs (or literature) on the frequency that Clause 19.3.4 acceptance criteria is involked for small diameter A312 TP304L pipe. This will help form a risk argument for the probability of cracks forming during an emergency crimp on a 3/4"nps sch40 pipe.
Here is the quote from A530 Clause 19.3.4:
"When low D-to-t ratio tubular products are tested, because the strain imposed due to geometry is unreasonably high on the inside surface at the six and twelve o'clock locations, cracks at these locations shall not be cause for rejection if the D to t ratio is less than 10."
Here is the quote from A530 Clause 19.3.4:
"When low D-to-t ratio tubular products are tested, because the strain imposed due to geometry is unreasonably high on the inside surface at the six and twelve o'clock locations, cracks at these locations shall not be cause for rejection if the D to t ratio is less than 10."





RE: PIPE FLATTENING TEST ACCEPTANCE PER ASME A530
RE: PIPE FLATTENING TEST ACCEPTANCE PER ASME A530
Would you care to provide a reference for the strain calculation metholology?
RE: PIPE FLATTENING TEST ACCEPTANCE PER ASME A530
RE: PIPE FLATTENING TEST ACCEPTANCE PER ASME A530
yamoffathoo, I didn't use any book, but just consider a long half tube being completely flattenned. The neutral plane is the half radius. Original lengths for OD, half radius and ID are 0.5*pi*OD, 0.5*pi*(OD-t), and 0.5*pi*(OD-2*t), respectively. Therefore, the engineering strain at ID surface is: 1/(D/t-2), which yields 12.5% when D/t=10. Similarly you can set up formula for OD strain. Plot them with varying D/t and you can see what I was talking about.
RE: PIPE FLATTENING TEST ACCEPTANCE PER ASME A530
Thanks, fyi ASME B31.12 Appendix D contains strain calculations for dents in pipes.
RE: PIPE FLATTENING TEST ACCEPTANCE PER ASME A530