Steam valve installed on pipe elbow

Danger8

Hi,
I have a home built in 1931 with single pipe steam heat. A few weeks ago I noticed a leak when the ceiling paint started bubbling. I opened the ceiling to find an old steam valve installed in a pipe elbow. This is about half way between the boiler and the largest radiator in the house. I think the valve failed so I decided to change it with a new valve and used a vari valve. It seemed to work for a while but now that has also leaked. I’m also getting banging from the radiator. Does anyone have any idea what I should do here? 

Any info would be greatly appreciated! Thank you! 

Steamhead

Is the boiler water level too high?

Also- is there a vent at the end of the steam main?

Jamie Hall

I'm going to bet that that pipe has sagged, and that water is collecting in the elbow. Check the pitch of the pipe going in both directions -- and maybe add some hangers, or adjust them.

nicholas bonham-carter

If that is meant to be a main vent, it is woefully small, and in the wrong place. The main vent should be after the last radiator. You are burning a lot of extra fuel to squeeeeeeeze the air out of a constipated little orifice.
The fact that it is leaking points to overpressure problems, as Jaimie has mentioned. Check that the pressuretrol is correctly set, and verified with a low pressure gauge, (0-3 psi). The pigtail may be plugged and causing the pressuretrol not to sense the pressure correctly.—NBC

Danger8

Thank you all for your responses, I will look into all of this immediately. I am not familiar with everything that you mentioned so I need to do some homework. I’ll work in it this week