How would you fix this leak?

[triggerman]

The headquarters of a big name retailer called us Friday. A 14" condenser water line had sprung a leak and needed to be welded. No problem, huh? There was one tiny little challenge to it. The pumps pushing water through this line at right about 45 PSI couldn't be shut off and the repair had to be made while the pipe was pressurized. We finally got it stopped. What a pain. The operators said they couldn't shut the pumps off, even for five minutes until Monday. And, they wanted the leak fixed last night. Fortunately they said those magic words "Whatever it costs". Yep, I'm a happy guy today. I think I'll go pick up that new Spectrum 375-X with my whatever-it-costs money.

[phaxtris]

piece of pipe with same id as od of broken pipe, a piece of tar paper where the pinhole was, clamp the ***** on real tight, and weld the outside edges

[dabar39]

How would I fix this?

I used to work in the citrus and vegetable processing industry for many years and did quite a bit of work in juice manufacturing plants. When ever we had a leak to contend with what we would do is get a piece of pipe that was the same i.d. as the o.d. of the leaky pipe, we would take it and cut it into two pieces and place a piece of gasket material under it and fasten it temporarily with hose clamps. That usually worked until they could shut down and proper repair could be made. The juice plants are all stainless tubing that had to be purged with argon for a sanitary welds. The pasterizing lines were always fun as they contained seven tubes inside the larger tube, the small lines carried the juice and the larger tube chilled it with glycol. The glycol lines were pressurized sometimes up to 2500 p.s.i. Dave

[Bert]

Dave,
How would you tighten down the "new" collars you made over the gasket material? I've seen plumbers use big hose clamps over gasket material/rubber, but if you use pieces of pipe, how could you cinch it down tight?
bert

[dabar39]

Bert

By placing a thin piece of gasket material over the leak, you then take a piece of tubing and cut in half or thirds whatever it takes to cover the area. Place the hose clamps around the patch panel and the pressure of the patch panel in turn puts pressure on the gasket material which then in theory stops the leak until proper repair can be made. All the piping in the juice plants are thin walled stainless and the patch will easily conform to the thickness of the gasket material . This method may not work as well with heavy gauge piping, but it wasn't stated what type of metal or the wall thickness was on the leaking pipe. Most of our repairs were made on 14 and 11 gauge stainless tubing and in most cases the i.d. was 8" or less. We have also used a stainless patch that is like a large hose clamp with rubber lining already on it but we didn't have much luck with those as they seemed to slow the leak instead of stopping it. Let me know if you are still unsure about what I'm talking about as I can say it better than I can type it. Dave

[Bert]

Thanks Dave,
now THAT makes a lot more sense

[fun4now]

yep i would go with the iner di. same as the outer and cut a pice to weld over the old pipe. whatever it takes for a bill sounds just too tempting to pass up i bet you have to exersize some real restraint when making out that bill. congrats on the spec375 should make the next pach go faster, i realy love my lil plasma cutter. just no substitute for a quick cut, just wish the consumables were a bit less $$$. i have the 125C so no real controle over air dryness or cleanlyness. add to that the consumables are more $$ for the 125 than they are for the 375 and i realy want to upgrade, the extra cut thickness would be nice also.
you chould be realy happy with the 375, my 125 has realy impressed me with its cut for such a small unit. at 5+ years old it still cuts like new.

[HMW]

How did you finally get it stopped and repaired?

[triggerman]

How we did it....

Normally, we would make a hot tap over the pinhole leak and just leave the valve shut off. The customer didn't want a hot tap, they wanted a plate to get out away from the leak into the meaty part of the pipe. We had a piece of 3/8" plate rolled to match the curvature of the 14" Schedule 40 pipe we were repairing. Everything went fine welding it up water pouring through the welds. We were running 1/8" 6010 5P+ at 250 amps to keep the puddle going under the stream of water. Anyway, here are a coupla pics of the repair.

[dabeldesign]

wow! That must have been fun

[Bert]

How do you weld with water still coming out?
bert
p.s. Is that a Craftsman 4 1/2 " grinder? and what was the bolt for?

[Winger Ed.]

I don't know if they're still around, but years ago when I did alot of commercial plumbing, the Plumbing Supply and/or Air Conditioner Supply houses had a clamp-on patch for doing that on a 'live' water system.

We'd get a leak in a chill water AC system, and use them as a permanant repair 'till Winter came along and we could shut down & drain the water out for welding the leak like 'normal'.

These patches were a strap of Stainless Steel about a foot long, size specific for the pipe, with a pretty thick neopreme sheet on the inside. The lengthwise edges were rolled up over a bar (on each side)and had nuts & bolts going through every couple of inches. The neopreme was thick enough to use/seal over a leaking weld seam joing two pieces of pipe together also.

We had to use one under a parking lot one time. We dug up/exposed the pipe, patched it, then a few months later, the parking lot got re-surfaced. We couldn't find it again. Rather than dig up a bunch of new parking lot, we just left it. Far as I know, its still holding, and that was about 10 years ago.

They worked great. All it took to use one was:
Find the leak, clean the area, wrap the patch around the pipe, put the nuts & bolts through, and tighten them down.


.

[Anti-GMAW]

Thats how they repair water mains usualy, same exact device. It's also a permanent solution, so you don't have to replace it later if it's instaled properly.

[HMW]

Here's a dumb question I see alot of guys use 6010 rods. Why? I have never used 6010. I have used 6011, 6013 alot and 7018 most, but it seems 6010 is mentioned alot. Is there something about it thats good for something special? I know 60xx is 60,000 lbs, and the xx1x is all postion, the xxx0 I think is DC only. So what makes this rod better than say a 6011??

[dabar39]

Hmw

I think it might be a territorial issue on rod usage. Down here in Florida ( or at least in my area) the rod of choice is 6011 or 7018 for most applications. I have traveled quite a bit thruogh out the country and each demographic area seems to have their own preferance. Is one really any better than the other? I can't really say as I have had good results with all types of rod, but I personally prefer 6011 as an all purpose rod over the others for general duty type welds. Dave