SpudFiles

Hi, i have finally come out of lurk mode after probably a year because i need some help in progressing in this amazing hobby!
I have been building pneumatics for many years and i now want to move on to using regulated gas feeding a piston piloted piston valved semi auto cannon.

The problem is i am about to buy an argon welding regulator on eBay and want to make sure it is suited for the job and is not going to regulate flow but chamber pressure.

I give you my word, i will be a worth while member if you invest help in me

(ps. i just picked up a fridge compressor mounted on a steel frame with a reserve tank made from an old (20 - 30 years!) patio gas bottle, i am a little unsure as to the safety of using this setup for 200psi+ due to the age of the tank, do i have reason to be unsure? (will upload pictures if wanted) )

Thank you for reading!

Joe

Rocketbat
Welcome.....
That is a flow regulator and not what you're looking for or need.

good thing i checked that! thanks a lot!
i best go cancel that order ...
any ideas for what type to use to bring my pressure down to 100-200psi from say a CO2 bottle? sorry about the daft questions, just a new field to me.

Pics of comp. and tank? Lets see what you have. Also argon regulators measure in Cubic Feet per Hour not in PSI like you need. Oxygen regulator set to the desired pressure with the gas flowing is what you need. Or just buy a CO2 regulator if you can find. Some of the oxy regulators only go to about 80 psi and might not mate up with the valve on your CO2 cylinder. However the valve on my torches' oxy cylinder is the same as CO2 and my smith regulator goes up to 250 on the gauge. I dont know if it will actually go this high in use as I only have set it to 30 for cutting/heating operations. Hope this helps.

I disagree with Velocity3X this time. This is a 2 stage pressure regulator. It will do the job just fine. That looks like a great price. Check the gauges on that regulator. Input tank pressure and output pressure. This is not a flow regulator. It is a pressure regulator. This pressure regulator can feed a flow regulator with a flow meter.

A flow regulator with a flow meter looks like this. Note the meter on top is measuring Liters per Minute. That is a flow rate.


As far as the Propane tank, if it is free of dents, rust and has always had some gas in it, it should be fine. If it was used for an air tank before or sat empty with the valve open, condensation and rust are a strong possibility as the inside is bare metal. Many fridge compressors are low volume but high pressure, so it will take a while to pump up the tank. The danger is leaving it unattended to fill with no pressure switch and no pressure relief valve. If you remove the original valve, it removes the relief valve with it as it is built into the valve.

Since the tank was used already as a reserve tank, I would assume it is rusted. Compressor tanks are painted inside and have a water drain. The propane tank has neither. Replace the tank. I would not trust it.

The two gauges should be an indicator that it is exactly as Tech said

I use both kinds at work.

oh balls! i will buy one off someone else
i was scared of internal rust so in the meantime, would below 100psi be ok?

here it is:


(the tacky paintjob was done by me btw)

I do not know without an internal tank inspection. With the valve removed can you pour out rusty water?

Internal tank inspections are often done using a fiber optic light to light the inside of the tank. A small bright LED flashlight may be used.

I agree w/ Technician1002 without looking inside how do you know what you are working with. BTW, that tank looks like a portable compressed air tank and should have some sort of identifying marks stamped in the outside of it, I.E. pressure ratings and a date of mfg. If you cant find anything like this maybe you should air on the side of caution and get a small propane tank to use with that compressor as the tank with the compressor is pretty large and would take a while to fill to anything above 250psi.

Tomorrow i will see if that hexagonal brass section will come out and try to get a camera inside, the compressor had a data sheet on the tank and the whole setup was built intended as a compressor to run up to 275psi (searching the name brings up nothing - multiplex 38HAX i think) so it may have possibly been coated.
Cant wait to get some of my copper guns running off this!

Edit: @ Motorfixer1: The only markings that were on it before i painted it was the number 82 and i presumed that was the year of manfacture, it showed signs that it used to have a cowl around the top joined at 3 points and it was origionaly "manky blue" so i think it was a 15 kilo butane bottle.

that looks more like ans 11 kilo...

Replace the tank mate. For 2 reasons:

1. You will never feel safe around it unless you can inspect it properly

2. It is so large that you will risk damaging the compressor due to overheating. The picture shows you have no cooling system. The longer it runs, the hotter it will get

lozz08 wrote:
2. It is so large that you will risk damaging the compressor due to overheating. The picture shows you have no cooling system. The longer it runs, the hotter it will get

The compressor has a cooling system. You are not recognizing it. The compressor is in an oil bath. This couples the heat to the case. The black case radiates heat and is convection cooled. The heat produced is limited because the power is limited. Many of these are 1/3 hp or less. If operated at the design load, they can run with a 100% duty cycle. If overloaded, they will overheat. Pumping a nominal 100-150 PSI is not a problem. Pumping high pressure does overload them.

If that tank was indeed a real compressor air tank it would have a water drain valve on the bottom. Without one, the regular task of blowing condensed water out of the tank would not have been done. Does the tank have a drain petcock?

Compressor drain valves are on the bottom.

lozz08 wrote: 2. It is so large that you will risk damaging the compressor due to overheating. The picture shows you have no cooling system. The longer it runs, the hotter it will get

my tank seems to be about the same size and i use a much smaller compressor. he will be just fine with his
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