PSV on vessel i/l line

[psvdesign]

Can anybody help me out, is there any standard that says about safety relief valve can not be installed on pressure vessel inlet line.
If vessel overhead nozzle & disharge line are smaller than PSV required orifice size, can that PSV be installed on vessel inlet line which is of higher size.
thanks,

 

[JLSeagull]

I think that inlet line installation is common. One thing to avoid is installation on an outlet line or vessel nozzle with a pluggable item such as a demister upstream of the relief valve. Installing the PSV on the inlet to a vessel is one way to avoid impact from a demister, etc.

 

[NozzleTwister]

A common reference is API Recommeded Practice 520, Sizing, Selection, and Insatallation of Pressure-Relieving Devices in Refineries.

Jonathan Livingston is correct, it can be installed on the inlet piping.

From a piping point of view it should be located so that it can be supported/restrained as required without having use springs etc.

NozzleTwister
Houston, Texas

 

[GenB]

If ASME vessel it will have to be a dedicated opening for controls/safwty valve unless the Inspector (jurisdiction) approve it in the inlet piping you will be okay.
all depends on the aplication and the Inspector.
genb

 

[unclesyd]

What few PRV's we have on inlet lines are lines where there is no valve between it and the vessel. Each installation has under go a design review and it's normally a chore not to put the PRV directly on the vessel.

We have this setup on some scrubbers that used Pall Rings where a change in operation required a new nozzle in the vessel for a larger valve. The time and expense to get a hot work and vessel entry required evaluating the placing of the PRV in the inlet line by means of a spool piece.