Steam return line fails every year

Paul S_3

The pipe that failed in the pictures is coming from the dry return of the system. It connects to the equalizer return tee where there shouldve been a hartford loop. System is one pipe steam. I repaired this section of pipe each of the last 3 years. This time I piped a proper Hartford loop. It seems to be failing at the weld of the nipple. My question is can this pipe be failing because there was no Hartford loop causing water hammer in that location? Thanks

Jamie Hall

How much stress is on that joint? And do the pipes vibrate? Can we see the full configuration? Looks much more like a fatigue failure from a lateral or up and down vibration and overlolad…

pecmsg

crap chinese pipe.
that little damage shouldn’t cause a leak.
Try Sch 80 nipples.

Pumpguy

You might also try a different material like stainless steel or brass. I've seen nipples this size in stainless for sale at Menards. Stainless is actually cheaper than brass.

Please keep us posted on what you end up doing and how it works long term. I have a customer with similar problem. They keep replacing with schedule 40 black pipe and continue to have the same problem. I just hear about this, but I'm not the guy doing the pipe changes.

delcrossv

I'd re do with red brass pipe and bronze fittings. Make the transition to black far above the waterline.

Jamie Hall

The guys above do have some useful comments on different components — but I'm not convinced this one is a corrosion problem. I still want to know what the loads on that fitting are.

EBEBRATT-Ed

How much MU water is being added to that system?

clammy

May seem like a silly question but where is your main vent located ? I ve seen dry returns that where un vented meaning right at the end of a main they would install a tee and vent and then properly reduce and run the return back to the boiler as a dry return w no vent at its end . I ve have seen this occur and upon repiping w a vent at the end of the dry return have not had the issue again . Make up water does play an issue but I believe that the unvent dry return may be helping form acidic condensate and be the root cause the issue .
i ve run across this where the wet returns are shot so being they have the height they run it back as dry returns and leave the old vents where they where and problem's solved .
peace and good luck clammy

Dennis

Too much make up, or poor air elimination. Install a digital feeder or water meter on the makeup. You might add some corrosion inhibitor or Squick the boiler.

Hap_Hazzard

https://forum.heatinghelp.com/discussion/comment/1826897#Comment_1826897

I agree with Jamie. Also, how tight are you getting this joint? Remember, residential steam is low pressure. With a good thread sealant, you don't need to get the joints that tight, and with the PTFE tape, it's really easy to overtighten things because it reduces friction.

mattmia2

If this is at the boiler, is the boiler throwing a lot of water in to the header that is flowing through the equalizer and in to this nipple? The pitting would seem to indicate it is corrosion. Maybe install it with the weld to the side or up so it isn't sitting in the water.