Pressure regulator question

[Metalmasterscm]

I want to use a standard pressure regulator as the exhaust on a two and a half inch bore 5/8 rod standard pneumatic cylinder. I'm trying to figure out the pressure I would need to maintain 130 lb of pull tension on the rod. Basically if I want to pull on the rod and have a constant tension upon it as it's being extended and use the pressure regulator regulate the exhaust. If nothing else could someone supply me the formula to calculate it myself.

Thanks a lot gang!

 

[Metalmasterscm]

Would this simply be area of the area of the piton minus the area of the rod and converted to PSI?

 

[3DDave]

The pressure regulators I know of limit the downstream pressure. You might be looking for something called back-pressure regulator, back-pressure valve, pressure sustaining valve or pressure sustaining regulator?

Anyway force = pressure times area; Pressure = force divided by area. The area is bore area - rod section area.

 

[Metalmasterscm]

Ahh, understood. So a standard pressure regulator is only controlling the differential pressure. So the back pressure regulator is basically like an adjustable pop off valve in layman's terms. Gotcha!

 

[LittleInch]

It depends on whether the pressure the downstream side of the regulator is fixed or not and how controllable you want it.

The advantage of a back pressure regulator is that it doesn't matter what the differential pressure is so long as its always positive and also it will regulate to a higher accuracy rating both + and -ve of the set point.

How does the rod go back to its original position?

Be wary of throwing terms around - a "Pop off" would tend to mean exactly that - i.e. it "pops off" and is gone and you have an open pipe.

You probably mean a spring pressure relief valve?

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[Metalmasterscm]

the rod's returned by either the remaining air [depending on how much can be handled] or it's going to be vented free and pushed back by hand.

 

[LittleInch]

Well you will need to pre load the cylinder to get the load at the start of the movement. So you need to let the roof go back under control.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Compositepro]

Use a quick-exhaust on the cylinder. It will exhaust, with almost no pressure drop, any pressure above the regulator supply pressure.

https://theinstrumentguru.com/quick-exhaust-valve/