3 replies to this topic

[Sara Owens]

I have a relief valve sized for thermal relief that is on the upper deck. There has been a change of pipe class changed from 300# to 600#. the relief valve inlet is 300# flange. is it necessary to upgrade the inlet flange to 600#?

[Bobby Strain]

Only you have the information to determine. Check the design temperature and pressure to determine.

 

Bobby

[fallah]

I have a relief valve sized for thermal relief that is on the upper deck. There has been a change of pipe class changed from 300# to 600#. the relief valve inlet is 300# flange. is it necessary to upgrade the inlet flange to 600#?

 

Hi Sara,

 

Appears something is wrong in the pipe class change at the TSV inlet line, because the pipe class change is normally happen at the TSV outlet flange (if needed) and it would be downgrade rather than to be upgrade. Hence please recheck and upload a sketch of the relevant PID to get more precise response...

[SawsanAli311]

 

I have a relief valve sized for thermal relief that is on the upper deck. There has been a change of pipe class changed from 300# to 600#. the relief valve inlet is 300# flange. is it necessary to upgrade the inlet flange to 600#?

 

Hi Sara,

 

Appears something is wrong in the pipe class change at the TSV inlet line, because the pipe class change is normally happen at the TSV outlet flange (if needed) and it would be downgrade rather than to be upgrade. Hence please recheck and upload a sketch of the relevant PID to get more precise response...

 

Hi Fallah and Sara, 

 

I think we need to check the flange ratings as per API 526 set pressure tabulations. If your PSV is a process thermal relief valve then it shall comply with API 526 inlet and outlet flange rating.

 

Fallah, I would like to know why there is a usual change applied to the outlet flange, is after confirming the PSVs rated capacity and the corresponding built up backpressure. I think Sara experienced a change in the upstream system's design pressure which mandated the change in the inlet PSV flange.

 

I also posted a similar detailed query on the flange ratings,  I need both of your valuable inputs on it:

 

https://www.cheresou...ressure-limits/

 

Thanks