The new Spec. PIM-SU-3541-C is based on the Minimum requirement for holding time. i.e. B31.3 top site Min. 10 Min.
Generally I am accept to maintain holding time 1 Hr. which more sufficient holding time prior to allow time to observe and inspect the whole piping joint connection.
However the official LTA has not finished yet. Upon finish I will launch it soon. .
Note for weld tester will maintain holding time as usual 10 Min.