Steam noise on 2 pipe convector system

Pickleman

Hi Everybody, I'm new to this site, but it looks awesome. I've heard much about Dan From school over the past many years because I am a plumber/pipe fitter.

I'm having an issue with a 2 pipe steam system that has convectors on it. I moved a convector on a 2nd floor room from 1 wall to another. I re-piped it from the basement and went up a different wall than the original. All the piping has good pitch and is taken right off the supply and return from the old piping location. I also kept the piping the same size as it was piped originally.



Soon after the homeowner complained of some banging noises going on in this room during the nighttime. I went to the house and realized that the supply valve wasn't open all the way. I opened it a full turn or so and haven't heard from them since. Now they are telling me that they hear a banging noise in the basement and 1st floor but not so much in the room where the convectors is.



I'm thinking about changing the steam trap and maybe the supply valve on the convector that I worked on. I'm assuming that the steam trap isn't working correctly and I'm getting steam in the condensate line. Is this a logical solution to this problem? Or is it something else within the system that is causing some grief? 



Any help on this would be great! I have done a lot more work on Hydronic Systems and 1 pipe steam systems, so I am new to this. 

Jamie Hall

Can you listen to it yourself?

because there are bangs, and then there are bangs.  If it's water hammer, and at the beginning of the cycle, something isn't pitched quite enough, particularly if the new runout is longer than the old one.  Not doubting your work, only thinking of my own experience!  On the other hand, could it be an expansion noise?  Again, most likely right at the beginning of a cycle?



Generally speaking, the feed valve on a two pipe system can be left partly open without banging., since (in theory at least!) the condensate is supposed to go out the other way.  And usually a bad trap will either produce no heat (stuck closed) or lots of heat in that radiator and poor heat in others (stuck open) -- but neither one will make a banging.



But if that new runout is appreciably longer than the old one, you could be getting condensate in it and a problem at the beginning of the cycle.  Is it insulated?

Pickleman

Pipe banging

The run off is longer but I would say only 4' on each one. I will try to insulate the piping that is there to see if that'll do it. I insulated some of the piping in the wall. I will also ask the contractor on which side of the pipe he put his insulation.

Pickleman

Pipe banging

Went to the job today and insulated what I could. I fixed 1 pipe was level instead of pitched. Turned the heat on for 90 minutes and no noise. We'll see what happens.

Jamie Hall

Do let me know

how it turns out -- but I'll bet you got it.

Pickleman

thanks

Thanks Jamie! I'll let you know.