Acetylene regulator pressure gauges

I just obtained 3 broken acetylene regulators from work. All three have working gauges, just the regulators do not regulate, which is bad for acetylene, over 15 psi it becomes unstable, 30 psi = boom. Anywho, I've been thinking about getting gauges for future projects, and was wondering is anyone had any suggestions about not using them for brewing related purposes. There are 6 total, all are pipe thread style, 3 of them read 0-15 with a redline to 30 psi, the other 3 read from 0-4000 psi (I believe). None of them say anything along the lines of "for acetylene use only". Actually, the only thing they have on them is the pressure readings, "psi" unit marking, and a company name.

Any reason not to use them?

 

I see no reason why they could not be used. Some may have left hand threads, so that's something to check. OTOH, gauges aren't very expensive, so if it were me, I would just buy new ones designed for use with CO2. The regulator is the expensive component, not so much the gauges.

 

I checked and all the gauges do have right hand threads, everything else on the regulators are left hand thread tho. I may check out prices of gauges, but like I always say, you can't beat free!

 

Fuels are usually left hand, oxidizers and inerts are right hand -

Propane, Mapp, hydrogen, acetylene, etc - left hand
Oxy, CO2, Nitro, etc - right hand

The gauges should not be that much different. Unless of course they are for Oxy, then they have to be cleaned.

 

I took them all apart today at work. There were actually 2 acetylene regulators and 1 oxygen regulator. The acetylene regulators do have left hand threads on the hose connections and tank connections, but the gauges on all the regulators are all right hand thread. One of the gauges that reads from 1-15, then redline to 30 psi, is stuck at 5 psi, so I probably wont be using it.
What I've been thinking about doing is hook up one of the 1-15 psi gauges to a portable CO2 charger for cornies so I would know exactly how much pressure it being pushed in, instead of buying one of those expensive regulated ones.