According to NBIC Part 2, Para 2.5.7 (a) PRVs must be tested Set Pressure, Reseat Pressure and Seat Tightness. Sub-Para (b), (c) and (d) explain test options. Para 2.5.7 (e) permits a "manual check" using the Try Lever (Lift Lever). However, this Manual Check does not prove Set Pressure or reset Pressure and in my opinion should not be considered a "Functional Test". It tells you the PRV is not stuck shut or frozen, but it indicates nothing about Set Pressure being within ASME Code Tolerance. It does not prove reseat within acceptable operating parameters, nor does it include a Seat Tightness test. As a member of ASME Sub-Committee Safety Valve Requirements, Chairman of ASME Sub-Group Testing & ASME PTC 25 Pressure Relief Devices, as well as Vice Chairman of NBIC Sub-Committee Pressure Relief Devices and VR QC Consultant to Numerous VR Holders including NASA and QC Consultant and Training Provider to numerous ASME Assemblers and Manufacturers, it is my opinion that the "Try Lever - Manual Check" does not provide sufficient data to qualify as a Functional Test of a PRV. PRV Functional Testing should include the Testing such as that as described in ASME Section VIII, Div. 1, Para. UG-136 (d)(4) and NBIC Part 3, Para 4.5.
JAC