Slow Venting Mains

nicholas bonham-carter

The second pressuretrol is a safety device, often with a reset button, which will shut off the boiler, if pressure rises above a higher setting, to avoid killing the main vents.
The button must be pushed to turn the boiler back on, and then you can investigate the cause of the over pressure.—NBC

usndave03

@tomsloancamp
 I'm not sure why there are 2 pressurtrols. Im guessing its for redundancy. One has a mercury switch the other does not. When I first moved here the pigtails where facing the wrong way...after reading Dan's book I changed the orientation to account for the expansion of brass pigtails. Turns out the mercury switch will trip the boiler if that expansion occurs in the switch's lateral direction.

usndave03

@SteamCrazy
Your suggestion on venting strategy for my mains are very interesting. I was hoping that I could just pipe off the current tapping and move it away from the end with piping (like legos  ) rather than taking a Sawzall to the main and reconnecting the condensate. I'm honestly a bit apprehensive about doing any kind of demo on my pipes. Perhaps I'll have the pros take a look it for a future project. 

@EBEBRATT-Ed
I like the idea of putting  the vents on longer nipples. Ill need to check my clearance at the floor board height and what accessibility will be like. 

I agree that in the end a combustion analysis and gas pressure adjustments will need to be done to determine and set the proper fire rate. At this point I leave it in the hands of the pros and pray this boiler works as the Deadmen intended.

usndave03

So I wanted to give a quick update on the near boiler repipe. The contractor came with a crew of guys and worked for 2 full days. They came with some monster pipe wrenches and fittings and got it done. My house and rads where shaking as these guys did their thing in the boiler room. Have a look at the end result. The steam significantly increased in speed getting to the end of my mains and all 18 of my rads get hot now. In the past I had a few problem rads that I have never felt get hot even after my system was on for 2 hours. The contractor left the fire rate the same for now becuase he needs to obtain a different orifice for the Carlin burner so im on standby for that. My next step is to optimize my main vents for 3/4" tapping and then balance the entire system. I ordered Gorton #2s and some fittings to attempt that project. Big shout out to Paul and his crew at ASM Mechanical.

Jamie Hall

SteamCrazy said:

I believe the only stupid question is the one not asked.  Answer could be redundency (a back up) if I'm not mistaking. 

That's it, in almost all cases (if you have a two stage burner -- rare in residential steam -- the second will be for staging). Cedric has three...

usndave03

Here are some photos of the return and Hartford loop. He had to use brass for part of it becuase the entire return is currently piped in brass. 

Jamie Hall

First comment -- there's nothing wrong with copper in the wet returns. No problem at all. It's just in the steam pipes where it is not recommended.