Help with bursting TIG cooler line

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HI all,I put an old Hobart TR250-HF back into service with help from members of this board. Everything was going along fine (except for a cooler leak now and then) and then I started to burn up torches despite having a cooler filled with water.Today I took the cooler apart and found the filter and tank was all gunked up with slime from old water from who knows when. I bought her this way several months ago.I cleaned the filter and the tank and everything worked ok UNTIL it sprung a leak right where the cooler connects to the feed line going into the TIG welder. The plastic hose bulged and then burst under the built up pressure. It seems that the water valve does not open until I step on the remote pedal. When it is just idling, the pump is trying to move the water and it burst at its weakest point. Attached is a picture.Question: Is this normal? I have had this problem since I bought the machine, but just repaired it and continued welding for another day or so when it would happen again. Since I don't use the machine on a daily basis I have only had to repair it a few times. However, now I am picking up more work needing the TIG machine and I need to find the problem or a work around.Anyone have an idea?Thanks,Tony Attached Images
Reply:If your feed line goes in the back of the machine to a valve then you also need a pressure switch to shut the pump down in the pump itself.Crap in the pump can make short work of the power cable in the torch also.Matt
Reply:first do not use a valve. second most of the Procon pumps have a bypass pressure relief valve built in to them. It is under the acorn nut and can be adjusted. Should set ant 60psi or less. A higher setting will cause leaking and burst hoses.Putting a Valve on this type of pump will cause it to over heat and heat the coolant up. The coolant stays in the pump. If the temp gets to high the pump grinds its self to death.  Unless the cooler has a built in pressure switch it is best to connect the torch to the cooler and bypass the valve.In older welders the valve was used for city water that ran through the torch and down the drain.  Some pumps do not have internal pressure limiting relief valves. They rely on an external relief valve. Pressure with these pumps is over 100 psi.
Reply:Thanks Matt and ccawgc for the information.  I found the relief valve and will adjust it.  I don't have a pressure gauge but will let the pump run until I see the bulge begin to form.  Then lower the pressure (counter clockwise, if I have it right) until the bulging stops.  In fact, before it begins to bulge, there is slight weeping at the clamp where the excess pressure forces itself around the twisted wire so I can adjust it until the weeping stops.  This should put it below bursting point and avoid the problems from letting the coolant stay in the pump.I'll check in after I get it going. If it fails to adjust, I will connect the torch directly to the pump itslef, bypassing the welder's coolant valve.Thanks again,TonyLast edited by therrera; 08-30-2010 at 12:09 PM.
Reply:Originally Posted by therreraI'll check in after I get it going. If it fails to adjust, I will connect the torch directly to the pump itslef, bypassing the welder's coolant valve.Thanks again,Tony
Reply:The flow of water through the running pump cools the pump as well as the torch.If you lower the relief valve pressure so you don't burn out hoses, when the valve on the welder is closed, you may end up burning out your pump.Just connect straight to the cooler, like everyone said.  The valve isn't for your cooler.
Reply:Hello all,well, I adjusted the relief valve and the pressure went down and no burst line.  However, given the advice I have gotten about by-passing the welder's valve, I will connect directly to the pump.  I did notice that although I reduced the pressure and the line did not weep nor bulge, that the pump housing got warm to hot.  I see what was happening.  The hot water, softened the plastic line going to the welder, making it bulge and burst right where it connected near the pump where it gets hot.I see you point, the the pump will still get hot with no circulating water when it should be running cool.  While I have been TIG welding for over 25 years, my work always involved air cooled torches.  This is the first welder I own that uses a water cooled torch and I don't yet know the idiosyncrasies of using one and their maintenance. Thanks everyone for your advice and help. Consider this problem solved.Once again, a thousand thanks.TonyLast edited by therrera; 08-30-2010 at 02:11 PM.
Reply:Take the valve out of the plumbing lines.Once you turn the pump on, the flow should go through the torch lines and the cooler and the pump continuously.  No on-off valve for the flow.  Pump ON = fluid flows through the lines.Pump OFF = no fluid flows through the lines.As said, the on-off valve is for when the 'coolant' is city water going into the lines and then just dumping down the drain or on the ground.  No pump and no cooler, just cool water from the faucet going into the torch lines and then exiting down the drain or onto the ground.  The best laid schemes ... Gang oft agley ...
Reply:I got it now!  Took a minute.  The reason for the valve was that there was a continuous supply of water and no tank, cooler or pump, just a steady supply of running cool water.  Thus, this model welder was not designed with a cooler in mind, hence it would mess with any cooler pump unless it was rigged up with a by-pass so it would ciruclate cool water from the cooler and back into the tank when not in use.  This was definitely back when water was seen as inexhaustible.  I think this model Hobart goes back to the late 70's or early 80's.  I have taken the valve out of the plumbing, bypassing it with a coupling to join the pump outlet directly to the torch inlet.Thanks again,Tony
Reply:Originally Posted by therreraIt seems that the water valve does not open until I step on the remote pedal. When it is just idling, the pump is trying to move the water and it burst at its weakest point. Attached is a picture.Question: Is this normal?
Reply:Originally Posted by MoonRiseTake the valve out of the plumbing lines.As said, the on-off valve is for when the 'coolant' is city water going into the lines and then just dumping down the drain or on the ground.  No pump and no cooler, just cool water from the faucet going into the torch lines and then exiting down the drain or onto the ground.
Reply:How much amperage are you using?Try back flushing your torch. A lot of times if there is gunk in the tank it gets layered inside the torch and that torch may not be good anymore. We would put a new torch on and all the problems would stop. In an emergency we would grab that torch with the build up inside of it, and it would heat right up. Different machine good pump.        Sincerely,             William McCormick
Reply:Thanks for the added info.  I have been using the torch hooked directly to the pump for the past few hours and it is working fine.  I am now I am using around 50 amps DC straight, working on some thin gauge stainless projects.When it burned up on me I was welding an Aluminum car hauler transmission that had severe cracks.  I was working around 150 plus amps in AC.The pump is running cool now that I changed the plumbing around and there is no sign of any leakage, bulging much less bursting of the line.Thanks again,Tony
Reply:Hi 7A749,Been a while since we spoke.  I'm OK with the hoses and stuff.  The burst hose actually has a lot of play in the form of extra length, so I lost a few inches.  It was not big deal in the grand scheme of things.Thanks for the offer,Tony