Safety Valve - Full life, Cv & pipe sizing for testing SV

[NBR90]

Hello,

Is there a formula for determining the maximum Cv or flowrate for say a 1.5" inner pipe diameter (Air pressure range: 100 - 2000 psi)?

The pipe is about 1 meter horizontal and 1 meter vertical from a 70 liter pressure vessel.

I'm trying to find out what will be the minimum Cv, given a pipe diameter, required to achieve full-lift on a range of safety valves from 1.5" to 8" with a variety of orifice sizes.

Is there a formula for calculating this?

Thanks in advance!

 

[gerhardl]

Normally you go the other way around:

Selecting an amount and a pressure to be relieved for a given fluid at given conditions in a given time, deemed to be sufficient to relieve the vessel to under critical pressure.

Then select a valve type and capacity suitable to do this.

If then still unsure, check the selected valve against all thinkable critical situations.

A pipeline would have a large capacity, most of the throtteling would be over the selected valve, better to use a concrete valve as an excercise to have an indication of what will be relieved.

Your vessel seems pretty small. If the vessel is closed the valve would also be small, but type of selected relief solution or SV could vary with type of content (toxic?, dangerous?, valuable?,gas or liquid or mixed? clean?).