We are performing a 450# hydrotest with the PTFE installed in the steel pipe. I doubt the PTFE liner could handle the pressure alone. I agree the tell-tale is irrelevant. I did find in B31.3 Chapter VII A300 (d) does state metallic piping that provides the pressure containment shall conform to...
ASME B31.3 like other codes sometimes cannot be straight forward. We are fabricating (welding) steel pipe with a PTFE liner. The steel pipe will have a tell-take hole to indicate if there is a breach in the PTFE liner. I believe this is still consider Normal Fluid service requiring 5%...
