3 replies to this topic

[Liando]

Hi All,

 

Need your help on this subject

 

Currently we have installed safety relief valve which is validated by third party.

They mentioned that the difference between inlet/outlet should be at least 1", where in my case, it is only 1/2" difference.

 

I have looked in API 520, 521, 526 but still unable to find this 1 inch statement.

 

Does anybody have any idea/reference on this?

 

Thank you in advance!

[fallah]

Liando,

 

Please specify you meant the difference between the sizes of the inlet/outlet lines of the PSV should be at least 1" or between the sizes of the inlet/outlet nozzles of the PSV itself?

[chemmu]

Dear Liando,

 

Good Day to you.

 

First of all you have to calculate the required orifice area for the required relief rate.

 

Based on the orifice area calculated, you have to select the orifice designation (D,E,F,G,H,J,K............) as per the API

 

The inlet and outlet sizes are as per the API standard only. Please refer all the designation with sizes to know the size difference between inlet and outlet.

 

Regards,

Chem.M

 

             

 

 

[demank]

Dear Liando.,

you may take a look into API 526.

You will see for inlet/outlet size of the PSVs from various orifice size.

 

For example, in the conventional Relieev Valve,

1D2 for inlet rating 600# and below

and 1.5D2 for inlet rating 900# and above