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A sweet little install with a twist (Big Honkin' Pipe)

Some of you may remember the Big Honkin' Pipe thread a while back posted by the homeowner trying to decode his steam heating system.  He invited me to Chicago this spring for some consulting and to see about replacing the boiler.  What we found is another previously unknown system  that looks and operates very similar to the Moline. Whats a little different is that there are no traps or special devices on the radiator outlets or any orifices at the supply valves.   It looks like steam was allowed to run into the return, like some other systems. Here's the  60 year old 250,000 input Weil boiler.  That new small piping up on the left is for the air vent that was missing from the system.  The homeowner had been tightening up the system and eventually it stopped heating.  He had closed up all the leaks that vented the air from the system, so steam no longer could get in.  The new main vent did wonders for the system and the fuel budget.

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  • The big Honkin' Pipe

    Here's the big honking pipe and some other oddball piping on the return side of the boiler.  We may never know what was once connected here, but we will forge ahead.

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  • Decifering the Big Honkin'Pipe

    Here's the something old that is something new.....A McDaniel Suc-Vac tee.  The top side is connected to the beginning of the steam main with a valve that looks like it can be throttled and also to the end of the steam main to vent the air out of the steam main.  There is also a throttling valve here.  The suction side is connected to the return main ( he new copper pipe is attached here).  As I originally found it, all air, water, and steam in the return passed through this device.  The Big Honkin' Pipe below acted as a steam/ water separator, sending the water back to the boiler and the air and steam out the pipe on the side to a condensing radiator located in the entry hall.  A return line from that radiator had the main vent on it and dropped back into the boiler water.  Air could pass from the system and any steam making its way to the radiator would condense and the condensate would return to the boiler.

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  • A new boiler.....

    Since this was a two pipe system and we were looking at orificing the radiators, if necessary, to virtually re size the radiation to the new heating load (home is now fully insulated with new windows etc.) we ran a heat load based on historic gas usage.  Our numbers came out  quite close to the homeowner's ( a fellow Architecture graduate from my Alma Mater, IIT in Chicago) at about 67,000 BTU/hr peak.  That put us at a 100,000 BTU/hr input boiler.  The homeowner wanted to be a little conservative, so we put in this 125,000 BTU Slantfin Galaxy.  We had looked at the more efficient Slantfin Intrepid with power burner, but the extra noise of the power burner was not acceptable and the extra cost was not in the budget.  We gave him an extra large 3 inch drop header with a 3 inch takeoff to virtually eliminate any possible water carryover into the system.  These boilers, when reasonably clean, have little or no carryover up to at least 180,000 input, despite the smallish 2 1/2 inch tapping.

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  • The boiler's running controls.....

    We dumped the el cheapo and unreliable Honeyell PA404 pressure control that came with the boiler and reused the reliable  and more accurate Mercury switch pressure control.  The homeowner ran the thinwall conduit to the boiler for 120 volt power.  We added our standard chemical port so we could add boiler cleaner to help clean things up when the installation was complete and system chemicals to reduce or eliminate system corrosion.  We piped up Slantfins very nice skimmer port.  Relief valves get piped in materials unlikely to corrode shut, so if the valve is needed it can do its job many years down the road.  The gage glass also got a blowdown valve because when new electronic Low water cut offs are used the gage glass no longer gets blow down at all.  We were fortunate, that clean out and drip built into the wall was put in years ago with a solid wall liner, so the chimney did not need lining.

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  • Details and operation....

    Here's a final shot of the return piping.  If you look carefully in the back of the picture you will see a new vapor stat installed on the end of the steam main.  Installed here it will get a more accurate and stable reading of the system pressure than on the boiler.  The violent boiling in the boiler tends to effect these controls and the small outlet piping in the boiler also tends to cause the pressure to be higher in the boiler than that even at the header, let alone at the end of the steam main.   The system has been running since the end of March and the homeowner had gotten the system well balanced by simply throttling the radiator valves, so it looks like no orifices will be needed.  The only radiator not heating was the condensing radiator, so we installed (or reinstalled) a drip line on the return so that the cold condensate would not condense the steam that jumps the venturi gap to the Big Honkin' Pipe.  This should help, and if not enough, opening the steam throttling valves should take care of the rest.  Moving to a boiler about 1/2 the capacity of the old should really make this installation pay for itself in reduced fuel bills due to higher seasonal efficiency.  Also, the home now heats much more evenly than it has ever before for the owners.

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  • Ron Jr._3
    Ron Jr._3 Member Posts: 603
    edited June 2010
    Very nice install

    Everything about the job is top notch , Boilerpro . From the drop header with system valve , to the brass nip and ell for the relief valve ........ And I'm glad to see a pressure gauge after the pigtail with the pressuretrol . What size is the tapping in the bottom of a gauge glass cock ? That's a great idea to add a blowoff there . The small one that comes built in won't last too long if you use an adjustable on it more than once ........  I wholeheartedly agree about the mercury switch pressuretrols too . I can't get a PA404 or L404 to work without setting the cutout higher than 3 psi or more .

    Excellent work , each and every phase of the job !
  • Tapping

    The gage glass is just a regular 1/4 IPS, so I just fit up a couple of brass nipples with a full port 1/4 inch valve.   One of the local boiler inspectosr put me onto this...its a great idea.  Thank you for comments...they mean alot when coming from one of the best in the field.

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This discussion has been closed.