Back pressure valve

[Elb.ab]

Hello,
I'm new here in this forum, and i find it amazing
I'm working on a bench test for testing check valves. I found some examples of this test where a back pressure is used at the outlet ( to the tank). I don't really understand what a back pressure valve does. Does it help maintain the pressure in a system? for example, if i connect my pump to it directly ( pump-> Back PV=> Tank), Would it help to rise the pressure in order for the circuit to function?
What are some of its characteristic that i need to design one.

Thank you for your time and help.

 

[zdas04]

A backpressure valve is simply a variable restriction in a FLOWING LINE that changes its flow area to try to maintain upstream pressure at a pre-set value. It only does anything at all while fluids are flowing in the line since they do not provide a bubble-tight seal. They consist of a way to sense upstream pressure, and a way to adjust the flow area in response to changes in the sensed pressure.

[bold]David Simpson, PE[/bold]
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

 

[Elb.ab]

Thank you for your answer.
So from whay you said. it's a variable restriction changing flow to maintain to inlet pressure. Does the formula for flow in function of drop pressure apply to it? : ( Q=C.S.sqrt(drop pressure/density))) .

Thank you again

 

[zdas04]

Not so much. Ever valve as a c[sub]v[/sub], but the flow area is irregular so the c[sub]v[/sub] is a function of the valve open percent. The manufacturers of these valves do a lot of bench testing in various fluids to be able to provide reasonable equations (and factors) for their valves.

[bold]David Simpson, PE[/bold]
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist