Patching a hole in a steam line

gfreynolds

 I have single pipe steam system with a pin hole leak in 2" line. I l'm thinking about trying to plug hole with high strength JWeld epoxy and adding a screw clamp with a rubber gasket? I had a four foot section of pipe replaced just before the leak that cost $ a year ago. I have also installed a new IBC boiler and hot water baseboard system. I kept the steam system for a backup. The boiler is only six years old.

Jamie Hall

That would work. For that leak. As you have discovered, however, when a pipe leaks from the inside, you really need to replace the whole section of pipe...

pecmsg

Skinner clamp until the pipe can be replaced!

mattmia2

Usually the mains only rust out when the boiler is throwing liquid water up in to them so you may have other problems or at least the old boiler had problems.

ethicalpaul

Boiler water is more corrosive than condensate?

mattmia2

ethicalpaul said:

Boiler water is more corrosive than condensate?

more plentiful

RTW

I had the same leaking issue on the mud leg pipe next to steam boiler. Someone on this site recommended using "silicone tape" found in plumbing supply stores until such time I had a chance to replace that small section (after the heating season). It did the job just fine and its been months

KarlW

Folks are right that you are most likely on borrowed time. When my return started leaking I tried patching it. It mostly worked, except, of course, then the The next hole opened up, and then the next.

I ended up replacing about 60 feet of pipe in the process within three months of my initial leak. The pipes lasted 102 years in my house.

STEAM DOCTOR

Might be a sag in the pipe, allowing water to accumulate. My knowledge of chemistry and physics, is quite limited. I would think that there's more of a risk of corrosion, when the metal pipe is exposed to moisture and air / oxygen. The return pipes are 100% submerged by water, which I would assume protects them to an extent. The means, if they have sitting water in them, would have the oxygen and water element. Just the thoughts of a physics fool. 

ethicalpaul

I would tend to agree with you, @STEAM DOCTOR but we see that wet returns rot out a lot faster than mains. I bet your wet returns weren't 102 years old, @KarlW

I admit I am confused how more plentiful boiler water in a main would cause more corrosion...it's only more plentiful during firing, then it drains just like the condensate. But there's clearly something going on.

Anyway, I hijacked too much already. @gfreynolds I'd go ahead and try a patch. It might last the rest of the year, or it might last for years. I saw a repair with some fiberglass material and resin wrapped completely around a 1 foot section of header, and it looked very solid. At our pressures, it's not much of an ask for a patch.

mattmia2

ethicalpaul said:

I admit I am confused how more plentiful boiler water in a main would cause more corrosion...it's only more plentiful during firing, then it drains just like the condensate. But there's clearly something going on.

More of the pipe is wet and for a longer period of time. If everything is pitched properly the condensate only runs in a little stream in the center of the pipe.

STEAM DOCTOR

ethicalpaul said:

I would tend to agree with you, @STEAM DOCTOR but we see that wet returns rot out a lot faster than mains. I bet your wet returns weren't 102 years old, @KarlW I admit I am confused how more plentiful boiler water in a main would cause more corrosion...it's only more plentiful during firing, then it drains just like the condensate. But there's clearly something going on. Anyway, I hijacked too much already. @gfreynolds I'd go ahead and try a patch. It might last the rest of the year, or it might last for years. I saw a repair with some fiberglass material and resin wrapped completely around a 1 foot section of header, and it looked very solid. At our pressures, it's not much of an ask for a patch.

Most mains are properly pitched and have little to no water in them

STEAM DOCTOR

To the OP. Definitely try a patch. I have seen mains, with rubber no hub couplings, catching up holes. I've seen some that were there for at least a few years. You need to get from now to the end of the heating season.

gfreynolds

Thank you all for you comments. I suspect there is a sag in the return line caused from settling or the first repair. It is just a back up system at this point. Just like the old radiators and I may attempt to replace the whole line in warmer weather. Although there may be a better problem as for the previous leak I was getting buckets of water.

Hap_Hazzard

mattmia2 said:

More of the pipe is wet and for a longer period of time. If everything is pitched properly the condensate only runs in a little stream in the center of the pipe.

When I installed the sight glasses on my return lines, I was surprised at how small the volume of condensate really is. It's barely a trickle. You can really see that 1:1,646 volume ratio in action. I wouldn't be surprised if the tiny amount of condensate left in a hot main at the end of a cycle completely evaporates in a few seconds.

ethicalpaul

Evaporates where?

(and as an aside, all the interior surfaces of the main are wet during the firing cycle and probably much later too--all the interior surfaces are condensing steam all the time)