Hi all,
We're running into an ambiguity where we can't really determine the proper definitions and rules.
We package gas compressors in Alberta, which includes fabrication of all piping (typically B31.3), pressure vessels, etc. As the majority of our packages are destined for northern Alberta or BC locations, we use low temp piping materials (A333 Gr 6, A350 Gr LF2 CL1, A420 Gr WPL6, etc) quite regularly, and our piping standards contain piping classes based on low temp and normal temp materials.
Where we run into some problems is related to the transition between piping inside our packages (MDMT -20F) and outside the packages (MDMT -49F). Sometimes our customers will call for complete use of low temp material, and this is no problem, as we just use the low temp piping specs. However, when low temp material is requested externally, but normal temp material internally, there's been two main ways this has been addressed, based on the specific customer request. Either we have a spec break inside our package at the first flange between the normal and low temp pipe classes, where the spools on each side are rated to -49F and -20F respectively, or we don't use a spec break, and only list one spool, but use the low temp material for the portion of the spool that is outside the package. So this single spool is only rated to -20F, but externally the materials used have been impact tested.
Our internal understanding had been that a spec break anywhere other than a flange or valve (i.e. where a spool can be disassembled and pressure tested) is not legitimate, which is why we do the second design above, where the materials used are partially low temp, but the documented spool rating isn't. However, we've run into an issue with a customer telling us that we should put the actual spec break on the flange, even though it's physically only one spool. We didn't think this would fly with our ABSA piping registration, but the customer tells us otherwise. So we are looking for some sort of documentation of the true definition of a spec break in an ABSA context, so we can properly understand what we are and aren't allowed to do. We have put out a request to ABSA, but I'm hoping someone here might have some understanding, or the ability to point us in the right direction.
We're running into an ambiguity where we can't really determine the proper definitions and rules.
We package gas compressors in Alberta, which includes fabrication of all piping (typically B31.3), pressure vessels, etc. As the majority of our packages are destined for northern Alberta or BC locations, we use low temp piping materials (A333 Gr 6, A350 Gr LF2 CL1, A420 Gr WPL6, etc) quite regularly, and our piping standards contain piping classes based on low temp and normal temp materials.
Where we run into some problems is related to the transition between piping inside our packages (MDMT -20F) and outside the packages (MDMT -49F). Sometimes our customers will call for complete use of low temp material, and this is no problem, as we just use the low temp piping specs. However, when low temp material is requested externally, but normal temp material internally, there's been two main ways this has been addressed, based on the specific customer request. Either we have a spec break inside our package at the first flange between the normal and low temp pipe classes, where the spools on each side are rated to -49F and -20F respectively, or we don't use a spec break, and only list one spool, but use the low temp material for the portion of the spool that is outside the package. So this single spool is only rated to -20F, but externally the materials used have been impact tested.
Our internal understanding had been that a spec break anywhere other than a flange or valve (i.e. where a spool can be disassembled and pressure tested) is not legitimate, which is why we do the second design above, where the materials used are partially low temp, but the documented spool rating isn't. However, we've run into an issue with a customer telling us that we should put the actual spec break on the flange, even though it's physically only one spool. We didn't think this would fly with our ABSA piping registration, but the customer tells us otherwise. So we are looking for some sort of documentation of the true definition of a spec break in an ABSA context, so we can properly understand what we are and aren't allowed to do. We have put out a request to ABSA, but I'm hoping someone here might have some understanding, or the ability to point us in the right direction.
