Good day. I found some topics here but none of them seemed to answer my question. Note this is for B31.3 Normal Fluid service.
I feel section 345-Testing in B31.3 does not do a well enough job describing testing requirements for threaded piping. I think I have 2 basic issues that need addressed. The first is that recently I have been told by my Operations group that when they replace a leaking nipple (B36.10M) in the field there is no hydro testing that is completed on it prior to install. I noted to him that all fittings (excluding those listed in B31.3) have to be leak tested, and I explained that this is required if there is a defect in the nipple. The response was that it wasn't practicable to hydrotest a small 100mm nipple. Note that I am unfamiliar (I had a brief look) with B36.10M) but I beleive nipples don't come stamped with a certified pressure rating similar to a valve or flange. So I would assume I am correct, that by code the nipple require pressure testing?
Now my second issue, is that leak testing is supposed to also test the connections. In an existing system it is not practicable to test the whole piping system to simply test 1 threaded joint. This also goes along with my issue above because really it IS impracticable to test a 100mm nipple because getting a good test would be very difficult with that low volume. As well, if you have a number of threaded sections that have valves between them, how do you complete a leak test on the system if you shouldn't leak test the valves? I've always treated these connections similar to flanged segments that were tested separately and then assembled in the field - with an in service visual test. Is this similar to what others have done / do? I wish it described an alternative test for threaded connections in 345. Thoughts, advice?
I feel section 345-Testing in B31.3 does not do a well enough job describing testing requirements for threaded piping. I think I have 2 basic issues that need addressed. The first is that recently I have been told by my Operations group that when they replace a leaking nipple (B36.10M) in the field there is no hydro testing that is completed on it prior to install. I noted to him that all fittings (excluding those listed in B31.3) have to be leak tested, and I explained that this is required if there is a defect in the nipple. The response was that it wasn't practicable to hydrotest a small 100mm nipple. Note that I am unfamiliar (I had a brief look) with B36.10M) but I beleive nipples don't come stamped with a certified pressure rating similar to a valve or flange. So I would assume I am correct, that by code the nipple require pressure testing?
Now my second issue, is that leak testing is supposed to also test the connections. In an existing system it is not practicable to test the whole piping system to simply test 1 threaded joint. This also goes along with my issue above because really it IS impracticable to test a 100mm nipple because getting a good test would be very difficult with that low volume. As well, if you have a number of threaded sections that have valves between them, how do you complete a leak test on the system if you shouldn't leak test the valves? I've always treated these connections similar to flanged segments that were tested separately and then assembled in the field - with an in service visual test. Is this similar to what others have done / do? I wish it described an alternative test for threaded connections in 345. Thoughts, advice?
