Step-down pressure of demin water line

[Wizard74]

I am looking for options to reduce the demin water pressure from a 8 barg header to about 5 barg for a downstream process unit. The downstream unit has been designed to work with a low pressure rating and there is a relief valve set at 5.5 barg. Anybody got any sugestions on what can be used to do that? Thanks.

 

[TD2K]

A control valve with a downstream pressure controller?

 

[Wizard74]

Thanks, TD2K. Is a control valve inevitable for a liquid service?

 

[TD2K]

I'm not quite sure what you are asking. I could assume the 8 barg and 5.5 barg pressure ratings are design pressures since you have a PSV set at 5.5 barg on the LP system.

Do you need to reduce the operating pressure? Are you trying to prevent the PSV from opening?

I don't know what your flowrate is to the lower pressure system but a control valve would be a pretty common solution. The dP across an RO will vary as the flow rate changes. The dP is likely too low for a hydraulic recovery turbine. We really need some more information on your system and what you are trying to achieve.

 

[Wizard74]

Sorry for the lack of information. The primary objective is to prevent the RV from lifting. So I guess a control valve will be a solution.