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Balanced system increased pressure

Fizz
Fizz Member Posts: 547
Happy New Year to all!  I recently throttled-back the short side loop on my Richardson system with hopes of getting more balanced system, and it worked, but with a few consequences: pressure went from 1-2 oz to 3-4 oz, and water hammer at one pipe before radiator.  I removed vent to open pipe, but pressure stayed same. The pipe where water hammer occurs is in a small add-on bathroom with no access.  Would going back to pre-throttle-back settings make a diffenence in water hammer, or is it a conincendental happening.

Comments

  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,849
    I don't think it's a coincidence.

    When you throttle something down you always increase the pressure behind the throttle. I'm not sure why you're getting water hammer, but someone more familiar with the Richardson system might. My only suggestion would be to throttle up the long side instead of throttling back the short side to achieve balance, but there's probably a reason why you couldn't.



    Just for clarification, is the hammer occurring on the short side or the long side?
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Fizz
    Fizz Member Posts: 547
    Water hammer is

    on the long side specifically at one of the non-Richardson add-ons from back in the late '20's.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    Throttling

    How exactly did you throttle back one side of the system?--NBC
  • Fizz
    Fizz Member Posts: 547
    Throttle-back

    done at supply valves on individual radiators.  Three of rads were heated top to bottom with el trap getting warm to hot every cycle, even on days when call for heat would be minimal.  After throttle-back, now on these few days with temps in teens, and single digits(supposed to go below 0 tonite), they will get fully heated. Other rad kept at setting, and got improved heat.
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,849
    Water Hammer

    So if you throttled back the short side you'd be forcing more steam into the long side. More steam means more condensate. If the higher volume of steam is trying to get by this higher volume of water, there's your water hammer. If possible, increasing the pitch to drain the condensate faster might help.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Fizz
    Fizz Member Posts: 547
    Increasing pitch

    is not an option with set-up, so I'm going to retrace my steps to one radiator at a time and see if it helps.  I'm not sure from your response if we are talking about a one or two pipe system, but Richardson is a 2 pipe. Thanks for your quick reply, it makes sense!
  • fixitguy
    fixitguy Member Posts: 91
    Richardson is a great system

    I have a bit of experience with the Richardson system and find that pitch is very important because with 3/4" pipe [particularly on a long run] steam & condensate do not play well together. The supply should be well insulated. All things considered you may not be able to throttle a rad down. The Richardson system was designed to be a vapor - Vacuum system back when coal burners were in vogue and that maybe the main vents are ng or in the wrong places. What sort of a trap do the add on rads have? Possibly one or more of them is shot and a source of imbalance, or too many add ons on the main.
  • Fizz
    Fizz Member Posts: 547
    Richardson and add-ons

    You might be right re: the 3/4" pipe.  My system has 3 add-ons, 2 were in one room(large kitchen) and are fed by a separate 11/4" run from a drop down from main, with a separate return and vent; the 3rd add-on( and this is where issue with water hammer occurred) is an attachment off an existing Richardson rad.  All add-ons have traditional traps, and are in good working order.  The 3rd add-on is fed by a lateral(3/4") which feeds both radiators, and the lateral is off a 1"run-out from main which runs 8' and then is reduced to 3/4" run(straight line) of 12' to a riser to 2nd floor rad.  Just before end of 1" pipe is a 1" lateral of about 6' to a riser to 2nd floor rad.  Now many prior posts have pretty much established that the culprit is too many rads off run-out, and solution is for replacing run-out with 11/4" piping.  The main issue is that rad attached to riser at end of run-out barely heats beyond supply valve, unless one of other rads on run-out is shut, or all others are throttled-back.  Getting back to problem with water hammer , I have re-set all valves on short loop to origninal settings and system is back to lower pressure and no hammer.