One for the welders. Exploded regulator!

[Zedn]

I finally got myself sorted out today with a bottle of argon to use my tig welder. I had an old regulator that come with a mig i bought second hand in 1999. Back then i was using it on a mix gas (D size) without any trouble. 10 years later i used it on the new bottle i got today. I got myself all set up and opened the tap on the gas bottle and kaboom. The regulator just completely exploded! It looked to be in good condition, guess not. I was extremely lucky that my head wasnt in font of it when it went or i might not be here to tell the story.

Did i do something wrong? Or was it just a crappy regulator?

I will be off to the welding shop tomorrow to buy a new regulator. I will be happy to spend some money on it, seeing the potential hazard it can cause.

[Rob. Smith]

G'Day Zedn. Nice to hear you didn't get hurt. Remember to open all gas valves SLOWLY. I've seen oxy regulators go into orbit when the valve was opened fast, like turning on a water tap. Any way you do it.. do it carefully. Now...what price are you paying for the argon ? I just bought a 'G' size bottle for $250 bucks. man thats a lot of bucks for a gas that flows pretty freely. Plus the bottle rent... I'm not impressed with BOC they have a monopoly and charge what they like. I spoke with a professional 'specialist' welder and he used to get the same sized bottle for $80 bucks, due to high use and trade discount. I'd love to play and practice with the tig but these prices put a stop to that. I've just got to attack the job and hope I do it right. so far so good.

[andyl]

One possibility is a bit of oil found its way into the valve during the 10 years of downtime. Oil is very dangerous indeed near gas gear.

[boxhead]

I have never seen the outcome but I too have been told that oil and gas dont mix.

As for gas supplies, how does this pricing compare?
http://cgi.ebay.com.au/E-Welding-Wel...item20b28fd27b

[Z-linkCobra]

Argon is an inert gas and non flammable. Oil would not have caused an explosin with argon. Oxygen on the other hand...yeah....basicly with oil in an oxygen regulator you have created a small deisel engine hanging on the side of a bottle.

Probably the spring had coroded a little in the regulator and when you hit it with 1400 psi from the bottle it broke. Sending 1400 psi into the low side valveing. Before you fire back up you might want to check your low side hose going into your welder...could have blown that off or up when it all failed. Also check your solenoid valve on your welder.

I never stand in front of a regulator when I turn a bottle on. I have seen the stem shoot out of an oxygen regulator before and punch a hole right thru the shop wall. Scary stuff.

I dont rent my bottles. Buy the bottle outright. You pay more up front but then its just gas charge after that. I dont know what size my bottle of argon is but the bottles about 4' tall +/-. When i get it exchanged it runs me about 30 dollars because i own the bottle.

Gene

[jcraigau]

Jeez Liam, hope it didn't take out any of those brick pillars!

[andyl]

Originally Posted by Z-linkCobra

Argon is an inert gas and non flammable. Oil would not have caused an explosin with argon. Oxygen on the other hand...yeah....basicly with oil in an oxygen regulator you have created a small deisel engine hanging on the side of a bottle.

I know what you are saying re argon but there would be some amount of air trapped inside the valve first time after a change too which might be pushed through the valve. I know if you oil an oxygen bottle you've got a very very big 'kaboom', but I thought there might be enough air in this case to fuel the explosion of the valve alone. I for one wont be experimenting to find out

[Jac Mac]

Originally Posted by Z-linkCobra

I dont rent my bottles. Buy the bottle outright. You pay more up front but then its just gas charge after that. I dont know what size my bottle of argon is but the bottles about 4' tall +/-. When i get it exchanged it runs me about 30 dollars because i own the bottle.

Gene

That might work in the USA where you have companies competing for business, but down under in Australia & NZ where BOC have a virtual monopoly on gas supply owning your own bottles is discouraged to say the least, If you do they seem to go out of the way to make life difficult, by loseing the bottle for a few days, or claiming that 'your' bottle needs a safety check virtually every time you refill..... just keep making life hard for you, I spend 3 times on bottle rental what I use in actual gas per annum...damn crazy just for the sake of being able to heat or weld anything..

[Zedn]

I dont think oil was the issue. Looks to be a really cheap casting. It was the 2 guage type with the 't' handle. It broke around the top of the thread that holds the diagram on and also where the T handle screws in. Was a clean break and looks to be a crappy casting, i guess it has just become brittle over time.

Rob,

I have my own D size bottle that a friend will be filling for me in the future, but at the moment his hose that he uses is broken so i rented this one from BOC. It was about $100 for D plus $13 per month rental. I am building my fuel tank at the moment so this bottle should get that job finished.

There is another company that competes with BOC, they are called supergas. I was told it was set up by an ex BOC person. My mate who will be filling my bottle for me next time, pays $75 for the big bottle that is about 6ft tall through supagas.

http://www.supagas.net.au/browse1.htm

The guy on ebay that Boxhead linked appears to be cheaper than BOC once you have the bottle.


Jamie,

no didnt get those trusty bricks. Shot straight up and nearly went through the floor under my wife watching TV above.

[Ronbo]

The rubber in the seat valve dry rotted and failed...

There's a small relief point in the diaphram that normally should pop or a relief valve on the side of the regulator body. In your case it sounds like you had a relief valve and it also siezed. Very rare to see a regulator bell blow off like that.

As mentioned before, no danger with inert gases and oil, just oxygen.

I used to repair welding equipment many years ago.

[Modena]

I did have a bottle of argoshield from Supagas, when it ran out I went back to BOC because the next size up was cheaper than Supagas...go figure

[OZVENOM]

Hi Zedn a lot of new bottles of gas and filled to a higher pressure to give you more gas in a given size of bottle they also charge you more for it. The down side is not all regulators can handle the higher pressure . check with your gas supplier on the correct pressure reg. I have had acouple of the diaphragm go on my regulators because of the higher pressure. its a trap higher pressure more cost for the gas and a new reg.
Oz..

[Zedn]

I went out and bought a new reg today and its all good now.

Ozvenom, the guage shows the bottle was just under 15MPa, label on bottle was 15.5MPa. Not sure if thats a lot or not. The regs i looked at today specify up to 20-25 MPa.