Natural gas compression using oilless air compressor

[Thaddeusw]

Hello,

First time poster so go easy on me ;-).

I was wondering if an oilless air compressor can be safely used to compress natural gas to around 60-100 PSI. My reason for doing so is I would like to use the very low pressure utility gas (.5 PSI)at my shop to run a cutting/welding torch. GTEC makes them but the price simply scares me. So I got to thinking.....

The compressor I was thinking of using is a GAST 4H model at 1/2HP (

http://www.gastmfg.com/piston.html).

The compressor is all aluminum except for the valves and rings, which are stainless steel. I would like a reservoir to hold the compressed gas before it was fed to a regulator, maybe a 1 or 2 gallon tank. All tubing would be copper with brass fittings. The only thing I would need is a pressure switch to cycle the compressor and a pressure gage to monitor the tank pressure. It seems strait forward in operation just feed the natural gas strait into the compressors intake port and pump it to the reservoir/torch. I know it can be very dangerous but I really want to have as much gas when I want it and not burn a hole in my pocket.

My first concern is that the motor isn't explosion proof. In the event of a leak, when the motor cycles on, the centrifugal start switch would create an arc that could ignite an explosive mixture. I will have to see if I can obtain a belt drive model or possibly change the motor to an explosion proof model.

My second concern is the heating of the gas due to compression. Should I cool the gas out of the compressor with a tube and fin type heat exchanger?

And last is my concern of any possible incompatibility of natural gas with certain materials to be used, such as tubing, fittings, valves, gauges, etc.

Thanks!

 

[Lhenrique]

vzeos

The link you posted was very helpfull to me! That's what I was looking for! Thanks
Thanks

TPL

That's was what I've told Warpspeed and Thaddeusw but using a small vessel instead of bottles.

 

[TPL]

That's was what I've told Warpspeed and Thaddeusw but using a small vessel instead of bottles

I fail to see why you are making it so complicated - where is the need to use a small vessel? This whole discussion is confusing what can be done in theory (home made kit - potentially dangerous with leaks etc)nd what should be done in a practical application - purpose designed welding/cutting equipment.

Just use a small oxy-acetylene kit with proper regulators - its not expensive and certainly a lot less dangerous than messing around with home made stuff.