Lighting a gas pipe

[Bod]

Referring to the article in your first link, which stated, I quote:

"Several factors can cause flash back, including failing to purge line properly, using improper pressure, leaks in your gas management system and improper system operation. We recommend using a flash back arrestor on your fuel line as well as the oxygen line."

This article obviously applies to oxy/acetylene safety. Why do you think that a normal flat would have an oxygen line?

For your info, Harry:

*A flashback arrestor or flame arrestor is a device most commonly used in oxy-fuel welding and cutting to stop the flame from burning back up into the equipment and causing damage or explosions. The two main types are dry and wet. Each has its own advantages and disadvantages. Most oxy-fuel flashback arrestors are the dry type.*

Another of your links, *bizarrely* refer to oil rigs and natural gas engines in the Gulf of Mexico. I quote from that link:

"There were 15 flash fires/explosions reported by OCS Gulf of Mexico Area oil operators during the first four months of 1973.

The last link refers to laboratory testing of Hydrocarbon molecules reacting with oxygen etc.

[Bod]

Yes, very strange.

[Uncle Peter]

He has the intelligence of a spambot/tailored advertising system. You get things which are supposed to be related but they aren't.

[Bod]

:-)

[Tim Watts]

On Friday 20 December 2013 18:05 [e-mail] wrote in uk.d-i-y:

Fascinating - I did not know about the powder bit - sounds *very* dangerous stuff (and I'm not normally phased).

[John Williamson]

(Video of a store full of acetylene cylinders going pop one after another.)

BOC training courses used to show a slow motion film of a cylinder exploding at one time, though I can't find it on t'internet.

It's easy to find out why, after a cylinder has overheated, even if it hasn't exploded, it needs to be kept in cold water for at least 24 hours.

Also, if your oxygen regulator is a bit stiff, *do not* oil the threads. The oil explodes as you open the tap, and wrecks the brass connector on the bottle, which then works like a heavy, fast rocket.

Mind you, if you're welding, it's wonderful stuff. Much more fun than the sparks.

[Uncle Peter]

Christ, I wouldn't want one of those exploding in a room next to me. I'll stick to arc welding.

[docholliday93]

+1 on that - I had a lot of fun at the local college doing gas welding. (It wasn't just a gas welding course, but I was happy to let the people doing car repair monopolize the MIG welders and content myself with gas welding plus an occasional bit of arc welding and TIG welding...)

[harryagain]

Why do you suppose flashbacks only occur in portable/ gas welding equipment? Flash back arrestors are fitted to these because the valves and the adjustment they give make it possible to have a flashback situation.

On a natural gas appliance there is no such possibility, it is designed out.

However if you go lighting an open gas pipe the possiblity exists of a flashback. The bigger the pipe the more likely it is.

If you can't see how the above links refer to flashback explosions and how they can ocurr, there's not much hope for you.

[harryagain]

Only because the gas mixture is infinitely adjustable by the user and flashback conditions can be set up.

On a natural gas appliance, the user can't make these adjustments, the gas mixture is designed in/not accessible to the user.

But they can occur if an open gas pipe is lighted.

[harryagain]

If you buy acetylene itis referred to as "DA", dissolved acetylene. Dissolved in acetone. To prevent unwanted reaction by the liquid sloshing about in the cylinder, the cylinder is fill with what looks like coke.

The cylinder should only be used in the upright position.

[Uncle Peter]

Cocacola? Cocaine?

[Onetap]

Coke. Residue from heating coal and removing the coal gas.

[Onetap]

Although Agamassan seems to be a white powder, so maybe cocaine was intended. I more familiar with coke, it's an old bloke thing.

[Uncle Peter]

I guessed that, I was just pointing out Harry's ambiguity.

[Uncle Peter]

And I'm more familiar with.... oops shouldn't say that in public.

[harryagain]

If I meant cocaine, I would have said cocaine.

[Uncle Peter]

How am I supposed to know that?