Non adjustable pressure regulator

[bdog]

I need to regulate compressed nitrogen down to about 750psi. Do they make a fixed regulator that will do this? I have been using $500 victor adjustable regulators similar to what is on a cutting torch but larger and am having problems with them breaking or getting out of adjustment due to the conditions they are in.

 

[Lelandwelds]

I need to regulate compressed nitrogen down to about 750psi. Do they make a fixed regulator that will do this? I have been using $500 victor adjustable regulators similar to what is on a cutting torch but larger and am having problems with them breaking or getting out of adjustment due to the conditions they are in.

That is usually spring piston territory. Low volume . Expensive.

Are you charging accumulators? With some juggling of volumes, this can be done without a regulator.

There were some fixed pressure regulators made When the scalloped neckring cylinders came out so you could use existing regulators on CGA 577 or whatever service. ( I forget the psi. 2950 or 3330?) Might be able to adapt.

Could try a reduced orifice and just cycle the cylinder valve.

Just guessing because you didn't include any relevant info or post a photo.

 

[cvairwerks]

Ah, if you are breaking regulators on high pressure gas bottles, you’ve got bigger problems than the regulators themselves......

 

[bdog]

Thanks for the replies. The regulator I am using currently is a Victor SR4G. The nitrogen is regulated to 750 psi and is used for a nitrogen spring. Looks like a hydraulic cylinder but is filled with compressed nitrogen. No nitrogen is consumed unless it leaks out or I have to bleed it off to service something.

This whole setup is mounted on a tracked vehicle that goes in very rough terrain. My problems are that over time the stem that goes from the bottle to the regulator cracks and leaks. Also the regulator itself seems to drift out of adjustment. Not sure if the big adjustment screw is actually turning or what.

I often turn on the bottle, set it to 750 psi and then turn the bottle off.

 

[scubadoober]

Single stage regulators will increase delivery pressure as the inlet pressure decreases. You could be seeing as much as a 5 psi increase in delivery pressure for every 100 psi decrease in inlet pressure (probably less). Are you setting your delivery pressure while gas is flowing? The last part about the ****** cracking: are you saying the regulator is attached to the cylinder at all times on the rig causing stress cracks?

 

[bdog]

What I normally do is back the adjustment screw on the regulator off a little bit and slowly open the cylinder valve. I then slowly tighten the adjustment screw on the regulator until I get to 750 PSI. I wait a little bit until it stabilizes to make sure it reads 750 psi after the nitrogen spring full.

Yes the regulator is attached all the time. The bottle is very securely mounted and it has one of this in use protectors for the valve. Sometimes our nitrogen springs develop slow leaks and I have to check and add more nitrogen throughout the day. As an example I set the pressure every morning, check it at noon, etc.

 

[cvairwerks]

Sounds like you need to remote mount the regulator. Shouldn't be any problem having a high pressure hose made up to go between the bottle and the regulator. You can then mount the regulator on some type of isolation to reduce the vibration.

The other thing you may want to look at is going to a dual stage regulator. As long as you have over 750 psig in the bottle, it will give you 750 into the spring.