Argon won't seal

[Maker]

My new argon bottle came today but I can't stop the regulator from leaking. It's leaking through the thread and I have no idea what to do now, I've tried tightening it more and the leak slowed but not fully stopped. Should I use PTFE tape? Is there something I should check isn't damaged?

 

[Paul.]

The seal is made on the brass bullnose not the thread, the use of tape although common is poor practice and should not be used, check the bullnose for damage, any bruising will allow a leak, light marks can be gently polished out with scotchbrite using a twisting motion, dont be temped to use anything more abrasive though, you will just make it worse, tighten the nut by had till the reg is just nipped but will still turn and lightly work it back and forth a couple of times in a twisting motion then tighten with a spanner as you twist ( in the direction of tightening)
The dark ring here shows where the seal is made, if the reg is ok then the cylinder valve seat may be damaged and you may have to return it as faulty, but the method I described usually works
See the setting up the gas page http://www.mig-welding.co.uk/wiki/Setting_up_the_gas

 

[Maker]

Thanks Paul. There is some ''scuffing'' on the regulator nipple, will fine wet 'n dry help (I've got no scotch bright).


PS. I'm aware the nipple and cylinder seat seal everything and the thread is purely mechanical.

 

[Maker]

Here it is.

 

[Paul.]

Not surprised its leaking then, If it was mine It would be getting replaced, actually if it was mine it wouldn't have happened a bit of tape wrapped round it in storage or put it in a box / bag etc would prevent that,
Forcing it into a cylinder as it is will likely damage the valve seat. you could try fine wet and dry followed by scotchbrite to clean it up, you have nothing to lose, the real answer is a new bullnose, that would need to be properly fitted nowadays and the reg tested, your local tradequip (boc) or most welding gear suppliers should be able to do it for you.

 

[Welderpaul]

That regs knackered and wants binning.

I find anymore than a couple of sharp slaps with the hand on the spanner to tighten means the outlet on the bottle is damaged and needs exchanging.

 

[Maker]

I'll see if I can get it repaired then.

 

[Maker]

Here's the back of the reg, It says "inspection 2014 replacement", Is it at the end of its working life anyway then?
What do you think of getting a cheap reg like this one vs a nicer one like the same(murex saffire ArC-35L)?

 

[nick952]

Just replace the nipple/bullnose/bottle stem, available online, but the thread will be either 1/2" X 27tpi or 1/2" x 28tpi.

Nick.

 

[langy]

View attachment 46368 Here it is.

Hahaha !!!

 

[Maker]

Hahaha !!!

That bad huh.

 

[Robotstar5]

Here's the back of the reg, It says "inspection 2014 replacement", Is it at the end of its working life anyway then?

For industrial use they would be binned by the date shown for insurance reasons, but as DIY use is much lighter it will last a lot longer unless damaged like yours.

 

[Fazerruss]

View attachment 46368 Here it is.

It can be repaired very easily. Unscrew the bull nose and put it in the chuck of a Pilar drill. Set the drill going and hold some emery paper over the end until the damage marks disappear.

 

[Maker]

It can be repaired very easily. Unscrew the bull nose and put it in the chuck of a Pilar drill. Set the drill going and hold some emery paper over the end until the damage marks disappear.

I personally don't have a drill press but I could give it to someone. Does it just unscrew or is there more to it than that. And does it matter if the shape isn't perfect, provided it's perfectly round?
You may have just saved me about £80.

 

[Fazerruss]

Unscrew it using a spanner on the hexagon part of the bull nose. As long as its reasonably spherical it will seal somewhere against the seat in the valve

 

[Maker]

How does the bullnose stem seal on the regulator? Is it another precision machined surface for me to **** up.

 

[Robotstar5]

How does the bullnose stem seal on the regulator? Is it another precision machined surface for me to **** up.

The ones I've dismantled have been very tight with threadlocker on and needed stilsons to remove, but as I was stripping them to weigh-in, damage wasn't an issue.

 

[hotrodder]

How does the bullnose stem seal on the regulator? Is it another precision machined surface for me to **** up.

AFAIK there isn't a single standard, as said earlier bullnose stems exist in several types including some that look like

but with a choice of thread of thread pitch and others that use NPT threads. NPT is probably pretty rare in the UK but might still be used by Harris or other American brands even though they're supplied here with BS341 cylinder fittings?

Personally i'd buy a new reg, yeah DIY use is very different to industrial but presumably there's still buildings/contents insurance in place and while extremely unlikely if there was an accident serious enough for the emergency services to be called and the remains of a regulator are laying about that clearly show it's out of date...

 

[Maker]

Thanks for all your help.My dad work with a guy who might be able to help but failing that I'm getting a new one, probably a cheap one.

 

[chevy2]

I've often seen in other workshops over the years where regulators have been removed from cylinders and then simply left to drag on the floor, they then wonder why they have leaks or lose a full cylinder of gas overnight where the valve has been left open,
the tapered part where it seals in the cylinder needs to near perfect, like its just been turned on a lathe.