TIG welder Regulator/Flowmeter

[ChrisBParticipant @chrisb35596]

Measured the thread on the cylinder valve and took some pictures to explain better. The pitch for the internal thread is 14tpi similar to bsp, internal diameter (this is the minor diameter) 22.5mm

Now while googling for this thread I came across a CGA 580 which apparently is used for inert gas cylinders in the states, the pitch for the thread is 14tpi as well but could not find any dimensions.

Markings on the cylinder valve

Internal thread and seat on the valve, as you mentioned Jason the regulator connector is rounded and does not seat properly.

Wobbly down

wobbly up

[MuzzerParticipant @muzzer]

When I moved to Canada, I discovered that N American cylinders have a different thread to the UK ones, so my regulators didn't fit. Can't pretend I was particularly surprised, although I was surprised to find that I could simply buy a replacement nosepiece (no idea what they are called but I'm talking about the stub that connects the regulator to the cylinder with the offending thread). It only cost a few dollars / quid. The main issue was finding out whether the thread in the regulator body was RH or LH (LH in fact). And when I returned, the original parts went back in,

So the cheapest option may be to see if your local welding supplier (or ebay) keeps such a part? If you don't ask you don't get and there aren't many countries that are weld free.

The US threads seemed to "almost" fit. But with a cylinder pressure of 200+ bar, you want to have pretty thick rubber pants on, house insurance that covers every window (and roof) in the house and make certain the cylinder is very securely anchored to take the risk. Alternatively it may be worth coughing for the correct fittings – just a thought.

Murray

[ChrisBParticipant @chrisb35596]

Rest assured I won't risk using it as is with the regulator I purchased. I called the gas company I bought the cylinder from this morning but the sales person had no idea what the thread size was, but said they had a regulator which fit my cylinder 100% for 125 euro… so it's either that or identify the thread on my cylinder and solve the problem with a 10 euro adapter (or whatever the connector is called!)

[JasonBModerator @jasonb]

On a 14tpi thread the difference between minor dia and major would be about 1.8mm so if we add that to your 22.5mm that comes out at 24.3 which just so happens to be the DIN 447 No 10 fitting which is given as the Argon thread in that link I posted above

 

BOC seem to list a lot of adaptors for DIN and BS sizes

Edited By JasonB on 26/06/2017 20:24:33

[ChrisBParticipant @chrisb35596]

DIN 447 no 10 looks like a male thread right? What I have is a female thread (see 2nd photo above) and it has a tapered part internally so it should be able to seal metal to metal without a washer….

I have found this **LINK** does the CGA 580 make sense, because the pitch is the same and the internal diameter of the thread is the same (ok +0.1mm) The cross section shape internally is the same as in the diagram, so I'm thinking this might be the thread.

I'll pay a visit to the shop tomorrow morning and try to have a chat with someone who knows what he's selling.

[ChrisBParticipant @chrisb35596]

This morning stopped by the gas shop to check if they have any adapters to connect the regulator to their argon bottle and surely enough they had. He looked at my regulator and remarked it's a British spec regulator, opened a drawer and gave me a nut, 12 euro later the problem was solved Asked him what kind of thread it had but he didn't know, he said all British regulators come with the wrong connection for their cylinders….the curious thing is they sell HiLo regulators which if I'm not mistaken are UK made…

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