psv selection and set pressure in CIP

[khansaab]

Hi all,

I am new here, enjoying the forum getting knowledge.

Can anyone help me to define the parameters required to selected a psv for chemical injection package. And how to determine the setting pressure for it.

 

[TD2K]

< Can anyone help me to define the parameters required to selected a psv for chemical injection package >

Identify the overpressure case or cases. For example, blocked discharge would be typical case to consider for a chemical injection package. Determine the required capacity and fluid properties for each relief case. Size the PSV for each case and the case with the largest required area sets the minimum area of the PSV you need to have.

The PSV setting would depend on the equipment and components. Basically, you can pick a pressure based on some margin above the maximum operating pressure (assuming all the components are good for this pressure) and use this as the PSV set point. Or, you can review all the components and identify the component with the lowest design pressure and use that as the set pressure. The component with the lowest design pressure on a chemical injection package might be the pump, might be flanges, might be the pulsation damper (if you have one), etc.

Start with API 520 and 521. Many of the PSV vendors will also have a catalog that will have sizing examples in it.