Help - Gas Not Turning Off and On

[BillyT]

Hey Guys, I need some advice,
I have a used welder that I just picked up, brand name Linde.

It is a mig with argon gas, actually that's the problem. When I turn on the gas bottle, and then I adjust the argon knob that allows the little silver ball to move up thus allowing gas to go through to the torch when the trigger is pulled. It must be malfunctioning because the gas comes out of the torch all the time whether the trigger is pulled or not. The only way to stop it is to turn the little knob off, thus making the little silver ball drop down and cutting out the gas.

My understanding of this equipment is limited, however correct me if I am wrong, but the gas should come on and off when you pull the trigger to start welding?

If I am correct in this assumption, then there must be a malfunction. Can anybody suggest what might be wrong, or a direction to investigate?


Billy

 

[mike 109444]

Welcome BillyT. Sounds like the gas solenoid is stuck open. Not sure where it is on that machine but if you follow the gas pipe going into the machine (youwill need to remove a cover or two, the tube will go to a device aprox 2" cubed with at least 2 wires connected to it. This is probley stuck/stuffed. The normal operation is that the valve should self close with no power applied to it as it has a spring inside to do this. There may be some muck or dirt just holding the valve open and stopping fro shutting off the gas. with the poer off try a light tape of the valve then turn on gas to see if that has stoped it. They can be striped and cleaned but beware the spring!! If you do strip it you will find a plunger with a rubber tip and the spring (not much to them!) clean the rubber tip and the housing that the rubber tip sits down onto. Failing that then replacement will need to be same rating as orignal, look on side for voltage some are mains rated and some are 12,24,or 48v

 

[zx9]

Welcome to the forum Billy, looks like quite a machine you have got there, when you get it working that is!
I am sure you know that the gas flow is controlled by a solanoid opperated valve inside the machine, I have never seen a touch connector like that (but I am just a home welder not a pro) however I expect the small two pin connector is the LV (usually about 24V but take care) switch feed to the touch. Try disconnecting the small plug and if the gas flow stops. Looking at it the ends of the black and white cable need securing within the plug so perhaps they are shorted.
Good luck, and report back with your findings.

 

[mike 109444]

There is one in this pic at bottom it's the blue cube( they are usually black!). You can see the braded hose going in and out of it

 

[mike 109444]

PS when working correctly the little ball in the flow gauge should rise when you first open the bottle valve then it will drop down again, this is the normal operation. Then when you press the trigger to weld it will rise as the trigger is held. This is the point at which you set the "flow" as gas is no flowing! You should set it to about 10lts per min assuming your flow gauge is marked in liters.

 

[Robotstar5]

Hi Billy, welcome to the forum, looks like you have a decent welder there.

When you take the covers off (make sure it is disconnected from mains) take a few pictures to post on here, could help us point you in the right direction.

 

[Jim_gsxr1000]

This is a nice looking bit of kit!

 

[chevy2]

Yep sounds like gas solenoid valve,
had one pack up once, gas came through ok but had give it a light tap for it to shut off.

 

[hairymel]

I have never seen a touch connector like that

as billyt is from canada i would guess that the 'euro' connector standard hasn't reached them there parts

 

[shenion]

It is probably a Tweco connection. Most older machines were adapted to them. It was the standard for a long time.

My Airco feeder has a similar adapter.

On this side of the pond, most machines use proprietary connections. Miller/Lincoln use variants on the Tweco connector.

Looks like HTP uses an eurotorch though.

 

[BillyT]

Got it ... Thanks guys

Got it fixed thanks guys. It was the gas valve as most of you gentlemen pointed out. Its a magnetic silanoid that opens the valve. It was dirty and after I cleaned it it worked fine.

Se pictures

 

[Robotstar5]

Glad you got it sorted, thanks for letting us know and happy welding

 

[Marc.]

As robotstar says, thanks for letting us know how you got it sorted! Usually people get the answers they need then never write to say if they sorted it out or not!