Relief temperature of the pressure relief valve 1

[apextec]

How to fill in the "Rel. Temp." column of the PRESSURE RELIEF VALVES Spec. form of ISA S20?

For example, if the relief capacity of fire case is less than block discharge case, but its relief temperature is higher than block discharge case, Thus we should use the relief capacity of block discharge case to sizing the relief valve. Then which temperature should i fill in the "Rel. Temp." colum? fire case's or block discharge case's?

 

[Chance17]

The spec sheet is going to purchase a safety valve to meet a quarantee set of conditions.
This is typicaly the contingency that used the largest safety valve area.
Fill in the temperature associated with the largest safety valve area.
There may be contingencies where flashing causes cold temperatures on the outlet.
You should note the low temperature somewhere on the spec sheet as a footnote.

 

[apextec]

Thanks a lot Chance

If i Fill in the temperature associated with the largest safety valve area, thus valve vendor can't consider the worst case of the temperature for your on material selection, does it OK? why?

 

[Chance17]

As a footnote to the spec, you can note the greater temperature due to Fire.

 

[apextec]

Thanks a lot Chance