4 replies to this topic

[Huba]

Hello,

 

I'm working on selecting heat exchangers for heating aqueous solutions (tube side) with saturated steam at 120 psig (shell side). Which side should have pressure safety valves installed? I`m also looking for general guidelines.

 

Much appreciated,

[breizh]

Hi,

Why would you need a safety valve on your HX?  

Normally you find safety valve on the steam header or steam pot to protect equipment downstream.

You need to investigate all possible scenarios prior to size the PRV.

Breizh

[latexman]

A heat exchanger with MAWP >= 15 psig on both the shell and the tube sides requires a PSV on both the shell and the tube sides. 2 PSVs; 1 per side.

[Huba]

Thank you for your input.

I`m considering an overpressure scenario where there is blockage of the tube exit (ie., isolation valves are closed because of maintenance and/of operator error) and the process fluid reaches boiling point.

As you mentioned Breizh, the steam header would be equipped with a PSV, so the shell side is covered.

Edited by Huba, 01 December 2022 - 03:05 PM.

[latexman]

As you mentioned Breizh, the steam header would be equipped with a PSV, so the shell side is covered.

As long as there is no valve(s) between the HX and header PSV. Some companies allow valve(s), but they have to be car sealed or locked open and have administrative control.