Every PSV is unique and identified by Tag No on the P&ID so you only have one bolting requirement for each.
I suspect you are trying to use one speco to cover all PSVs of the same rating and size combination.
Dimensions are diferent depending upon whether it is spring or pilot operated, What orifice is used, and what manufacturer model No is purchased.
The inlet bolt length may also vary dependant upon the same criteria.
for instance a Crosby Spring operated 150#x300# 4"x6" PSV has 4 different inlet/outlet dimensions depending whether the type chosen is JBS JLT OR JOS, Whether the Orifice is M N or P and what the required flow rate is. That is after consolidating all the variations they provide, (there are at least 23)
And that is just using Spring type from one manufacturer.
If you switch to a different manufacturer you add more possibilities.
Add in Pilot operated valves and there are even more.
So one try to cover all PSVs with one speco will almost certainly never work
Every PSV is unique and identified by Tag No on the P&ID so you only have one bolting requirement for each.
I suspect you are trying to use one speco to cover all PSVs of the same rating and size combination.
Dimensions are diferent depending upon whether it is spring or pilot operated, What orifice is used, and what manufacturer model No is purchased.
The inlet bolt length may also vary dependant upon the same criteria.
for instance a Crosby Spring operated 150#x300# 4"x6" PSV has 4 different inlet/outlet dimensions depending whether the type chosen is JBS JLT OR JOS, Whether the Orifice is M N or P and what the required flow rate is. That is after consolidating all the variations they provide, (there are at least 23)
And that is just using Spring type from one manufacturer.
If you switch to a different manufacturer you add more possibilities.
Add in Pilot operated valves and there are even more.
So one try to cover all PSVs with one speco will almost certainly never work
