200DX gas solenoid making weird noise. sometimes no flow

[Frank]

just bought this tig welder got everything hooked up, i notice that every once in a while when i press the trigger on the torch switch the gas solenoid makes a weird sound and no gas flows out of the torch.
i have my preflow at about .5-1 and my post around 14-15 sec.

the gas should flow regardless even if there is no arc , as long as i press the switch on the torch correct ?

I have not tried using the foot peddle yet.

what activates the solenoid ? the arc or the switch on the torch ?

maybe its my error ?


thanks in advance
Frank

[Frank]

argon tank is full , and valve is full open, regulator is set at 14

[Paul Moir]

Yeah, that's weird. Gas should start flowing the instant the switch is pressed. It stops flowing once thepostflow timer runs out, which starts when the switch opens. So every time you hit the switch, you should hear a "Pfft..." no matter where it is.
Try the foot pedal since it has a switch too which works the same way. That will rule out a bad torch switch.

Arc should have nothing to do with it.

PS - that sounds like a lot of post. I set pre to start the arc after the initial blast of gas has cleared for a good crisp start and post to keep the tungsten (and occasionally work) clean. That's about .5 and ~5 seconds?

Oh, are you using the everlast flow gauge, which is in lpm? Set around 7lpm! (0.5lpm ~= 1cfh)

[Frank]

I have the Everlast CFH regulator set at around 14,
I will set my pre flow for 1sec and post for 5 sec for test
also i will try the foot peddle, so i understand correctly ....
as soon as i press the foot peddle i should hear the gas flow amd when i let off the peddle the gas should continue to flow (to what ever i have my post setting at)? correct ?

this will rule out the torch switch as you mention?, if it doesn't i possibly have a faulty solenoid *Possibly**

also i might take apart the torch so that i can have a better listen to the flow of gas, obviously not directly in my ear , lol

[Paul Moir]

Yeah, I think Rambozo said your eye's would pop out of your head if you did it with the HF on... Sounds about right; I haven't managed to try that yet.
Ah, the new style flowmeters are CFH now are they. Nevermind - 14 should be fine.

Yes, you should hear gas flow as soon as you press the foot pedal a bit, and should stop after you stop pushing the foot pedal *and* the post setting runs out. The idea with postflow is you shield the tungsten (and sometimes the metal being welded) until they cool off enough so they don't oxidize. The tungsten turns grey or blue (ie, dark not shiny) if it's not postflowed enough. Too much postflow is a waste of gas.

Possibly a faulty solenoid or a faulty regulator if the pedal does the same. Sometimes they stick for like no reason. Everlast will know the failure modes *way* better. Give them a call.

[Frank]

Today I set the foot peddle and set my pre flow at .5 and my post flow at 5 , I brought my cfh up to 25 so thati could hear the flow, what I notice is that I can hear the pssshhhhh gas delivery on start up then when I let of the peddle I have to wait until the post flow finish it's cycle , otherwise the solenoid makes that weird noises described . Once the post flow count down is finished I can start back up and I have gas. Does this sound correct?

Or should I be able to continue to press the peddle and begin flow again before the post flow finishes ?

[Rambozo]

Or should I be able to continue to press the peddle and begin flow again before the post flow finishes ?

Yes, you should be able to hit the pedal during the post flow period. In fact that is a typical technique to eliminate the preflow delay. I do it all the time. Set the preflow to 0, then tap the pedal before the torch is in position, and while the post flow timer is going, you let the argon flow stabilize and position the tungsten. Then when you hit the pedal again, the arc starts instantly. This is a method that let's you get different lengths of preflow for different positions without having to make adjustments to the machine, and no start delay is nice for best control.
What you don't want is to try to start an arc during that initial blast of argon. I't too turbulent and there is a lot of air sucked in. There are ways to try to control that blast, and this is one of them. Some solenoids can make a noise. They shouldn't, but occasionally there will be a buzzing from the coil or a gas flow noise. As long as the gas flow is constant and steady, you're fine.

[performance]

The noise you are hearing is likely the HF trying to fire.

[Frank]

Yes, you should be able to hit the pedal during the post flow period. In fact that is a typical technique to eliminate the preflow delay. I do it all the time. Set the preflow to 0, then tap the pedal before the torch is in position, and while the post flow timer is going, you let the argon flow stabilize and position the tungsten. Then when you hit the pedal again, the arc starts instantly. This is a method that let's you get different lengths of preflow for different positions without having to make adjustments to the machine, and no start delay is nice for best control.
What you don't want is to try to start an arc during that initial blast of argon. I't too turbulent and there is a lot of air sucked in. There are ways to try to control that blast, and this is one of them. Some solenoids can make a noise. They shouldn't, but occasionally there will be a buzzing from the coil or a gas flow noise. As long as the gas flow is constant and steady, you're fine.

Thanks that actually an excellent way to take care of the turbulence, makes perfect sense to have pre flow at zero and just purge from your post and begin . Thanks, I'm going to apply that technique . I was able to figure out that weird noise I was talking about , it was in deed the hf sound coming from the machine as performance above has posted. I turned up the cfh o listen on the torch and yes it is coming on / stays on during post flow if I hit the peddle , indeed it was operator mistake but glad that I was able to solve this with your guys help,
Thank you !!!
Frank