Oxy/ Acetylene light procedures and safety

[FunkyfullWidth]

I was always taught to turn on the fuel weather it be acetylene or propane first, then oxygen. Then apon shut down kill the fuel, then oxygen. Recently guys keep coming into the shop thinking that they know what they're doing and cranking both valves open and trying to light it. I yell at them some and usually just do it for them. I've tried to explain the proper (afaik) way to do it, but it means little to them.

What can go wrong with trying to light a torch improperly.

 

[TwetoGAC]

You are doing it correctly. The dangers or turning off the oxygen first is the possibility of sucking the flame into the hose. Normally the only way this can happen if the oxy-acetylene hose is worn and cracked letting outside air into the hose.

Also, never, never, never stand in front or behind an Oxygen regulator when you crack it open. When I was in welding school, I cracked an oxygen regulator first thing in the morning and it blew out. The adjustment screw blew out of the front of the regulator and the the back of the regulator blew knocking a hole in a steel plate directly behind it. Always stand to the side of the regulator when opening it.

 

[Rogue1987]

Oxygen Regulator Burnout is a danger:
http://www.weldingtipsandtricks.com/welding-accidents.html

 

[Thedroid]

It actually depends on the brand of torch your using. The Victor torch instructions specify that the oxygen be turned off first, and then the fuel. Look up the instructions for your particular brand of torch and regulators.

 

[e-tek]

You are doing it correctly. The dangers or turning off the oxygen first is the possibility of sucking the flame into the hose. Normally the only way this can happen if the oxy-acetylene hose is worn and cracked letting outside air into the hose.

Also, never, never, never stand in front or behind an Oxygen regulator when you crack it open. When I was in welding school, I cracked an oxygen regulator first thing in the morning and it blew out. The adjustment screw blew out of the front of the regulator and the the back of the regulator blew knocking a hole in a steel plate directly behind it. Always stand to the side of the regulator when opening it.

Exactly - on both counts. I always stand to the side of my regs! But flame arrestors (mandatory now) protect you from ****-in.

In the end tho, it's all highly theoretical. I've been around welders since I was knee-high to a Mini-set and - although I've seen a lot of side flames - have never seen something go really wrong.

 

[welder4956]

Lighting and shutting down - from the horse's mouth:

Turn on the fuel gas first, turn off the fuel gas last. That was the way I was taught, that is what the manufacturer recommends.

 

[Higgins]

That's scary................. If they don't know how to start and turn off a tourch, they shouldn't even be near one! Let alone use one! They needto be using flash back arrestors, so they don't kill someone!

Ditto on standing by the regulator. Had a neighbor using a cheep regulator blow the adjustable tee right thru the garage wall. That's what U get for purchasing thast "Cheap" junk from China!

 

[camjeep3]

At school we went over the procedure for over a week. My teacher kept pounding it in our heads. I'm Glad he did. He also said stand behind the tank and peak around when you crack it. We were taught fuel on and off first.

 

[Big-Foot]

You are doing it correctly. The dangers or turning off the oxygen first is the possibility of sucking the flame into the hose. Normally the only way this can happen if the oxy-acetylene hose is worn and cracked letting outside air into the hose.

Also, never, never, never stand in front or behind an Oxygen regulator when you crack it open. When I was in welding school, I cracked an oxygen regulator first thing in the morning and it blew out. The adjustment screw blew out of the front of the regulator and the the back of the regulator blew knocking a hole in a steel plate directly behind it. Always stand to the side of the regulator when opening it.

X 2 or 3 on this...

You gotta love the bozo in the shop that lights first with the acetylene on full blast and no oxygen.. Little black parachuters throughout the whole darned shop! .

Try to teach them but some guys just can't figure it out...

 

[isaac338]

That's what U get for purchasing thast "Cheap" junk from China!

Yeah, nobody's ever had an American-made regulator fail!

 

[welder4956]

Ditto on standing by the regulator. Had a neighbor using a cheep regulator blow the adjustable tee right thru the garage wall. That's what U get for purchasing thast "Cheap" junk from China!

Flashback arrestors would not have prevented this if it happened before the torch was lit. This is exactly what the check valves are intended to prevent. Without the check valves, acetylene could inadvertently backfeed all the way to the oxygen regulator when the tank goes empty or the regulator or tank is shut off with the torch valve open. When the cylinder is opened and oxygen regulator adjusted the acetylene explodes under high pressure. Acetylene is not stable at pressures over 15 psig. There are a lot of torches still in use that were made before check valves and flashback arrestors were integrated with the torch body. If you don't have both, get a set at the welding supply ASAP.

 

[welder4956]

Yeah, nobody's ever had an American-made regulator fail!

I wish that were true. I've seen several Victor regulators fail. It's not about where they were made (Although I don't like the cheap overseas ones either).

 

[tkonetzke]

You should Never run a tank completely empty, leave about 15 to 20psi in the tank, otherwise you run the risk of contamination.

 

[justanengineer]

Since nobody else said it, something I always found amusing yet always remembered - "A before O or youll go!"

 

[marineengineer]

any one ever seen someone light a torch with the tip on a bench. An old ship yard worker i now does this.... and hes been burning plate for 35 years for ship repairs. ive never asked him why but this thread makes me wonder if there is a reason to him doing this. He puts the tip on the bench then turns on the fuel lights a flame then brings the oxygen into the flame with the tip on the bench until he gets the points in the flame he wants. He knows a lot more than most about torches but hes the only one i have seen do it this way. does it help stop the flame from being blown out by the wind?

 

[Kevin54]

I replied in the thread about the rosebud about having spark arrestors on your setups. We have seasoned guys that don't have a single clue how to light a torch. Either they have a room full of soot, or the thing pops, bangs, and when I hear it whistling I have to go up and shut it off because they can't figure out what the hells going on. I am surprised that one of them never blew the place up.

 

[BJ42LX]

any one ever seen someone light a torch with the tip on a bench. An old ship yard worker i now does this.... and hes been burning plate for 35 years for ship repairs. ive never asked him why but this thread makes me wonder if there is a reason to him doing this. He puts the tip on the bench then turns on the fuel lights a flame then brings the oxygen into the flame with the tip on the bench until he gets the points in the flame he wants. He knows a lot more than most about torches but hes the only one i have seen do it this way. does it help stop the flame from being blown out by the wind?

Taking from welder4956 above, somehting like this:

 

[PCO6]

Since nobody else said it, something I always found amusing yet always remembered - "A before O or youll go!"

My Dad always told me "A before O" but I never heard the last part. Makes sense though.

 

[ZRX61]

Worked one place & the shop foreman comes up to me one day & asks what I did "to break the MIG welder?"

Didn't know WTF he was talking about.... Turns out when I'd used it the day before I'd shut the gas valve when I was done with it.... ******* *undocumented worker* didn't know how to turn it back on....

 

[Garage5.9]

Worked one place & the shop foreman comes up to me one day & asks what I did "to break the MIG welder?"

Didn't know WTF he was talking about.... Turns out when I'd used it the day before I'd shut the gas valve when I was done with it.... ******* *undocumented worker* didn't know how to turn it back on....

Genoiousssssssssss

 

[e30bradley]

Yeah, nobody's ever had an American-made regulator fail!

I have US made victor regulators from the early 70s is iirc.. The guy I bought them from used them daily at the scrap yard he worked at. They still work nice.

 

[FunkyfullWidth]

Lighting and shutting down - from the horse's mouth:

Turn on the fuel gas first, turn off the fuel gas last. That was the way I was taught, that is what the manufacturer recommends.

Interestingly enough that video shows the guy turning on the fuel, then oxygen and when shutting off turns off the oxygen first then fuel. I suppose it does depend on the torch. some torches I've noticed that if you shut of the fuel followed by oxygen it'll pop when others won't.

 

[Kevin54]

Interestingly enough that video shows the guy turning on the fuel, then oxygen and when shutting off turns off the oxygen first then fuel. I suppose it does depend on the torch. some torches I've noticed that if you shut of the fuel followed by oxygen it'll pop when others won't.

I always turn on the Acet. first then the Oxy, to light it, but when I shut it off, I shut off the Acet first to put out the flame then the Oxy to blow out any soot or small flame that there is still left from the hose. Then I turn the tanks off and open the valves on the torch to let the oxy / acet out of the lines.

 

[pfarber]

Lighting and shutting down - from the horse's mouth:

Turn on the fuel gas first, turn off the fuel gas last. That was the way I was taught, that is what the manufacturer recommends.

That video was a Community Collage shop teacher and a Salesman. What a so 'authoritative' about a that?

I shut down by turning off the O2 first, then the fuel (either acetylene or propane) two years now... no issues.

How can you **** flames into the 02 hose? THE VALVE IS CLOSED!

"You should Never run a tank completely empty, leave about 15 to 20psi in the tank, otherwise you run the risk of contamination. "

This is semi true. If you run an ACETYLENE tank low, you can **** acetone into the regulator (acetone is in the acetylene tank as a stabilizer) where it can eat the diaphragm. That's also why you never lay an acetylene tank horizontal... if you do stand it upright want 30 minutes for the acetone to drain back to the bottom.

 

[e-tek]

There are a lot of torches still in use that were made before check valves and flashback arrestors were integrated with the torch body. If you don't have both, get a set at the welding supply ASAP.

You are right on the first count at least - there are LOTS of old set ups out there - and none have ever caused problems......

I wish that were true. I've seen several Victor regulators fail. It's not about where they were made (Although I don't like the cheap overseas ones either).

Ahhh, yah, that's what's he meant.

Interestingly enough that video shows the guy turning on the fuel, then oxygen and when shutting off turns off the oxygen first then fuel. I suppose it does depend on the torch. some torches I've noticed that if you shut of the fuel followed by oxygen it'll pop when others won't.

It really just doesn't matter which is turned off first. Turn off the O and you get a yellow flame to turn off last. Turn off the A and you get oxygen to breathe in. I used to work with an old timer that would **** O2 when he felt tired....

 

[bgarrett]

I used to work with an old timer that would **** O2 when he felt tired....

The guy at the gas store told me that all oxygen is medical grade. He said they are not going to make two grades.