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Boiler Back Flow Preventer...Testable or just Vented?

JUGHNE Member Posts: 11,086
Doing a risk analysis system study for hospital...the Legionalla issue again.
A: CW feed lines to 2 steam boilers each with simple single check valve as BFP.
B: CW feed line to water feeder pit- electric solenoid valve--2 ped pumps--chemical feeder point...no check valve at all.
C: CW feed line to hot water hydronic heating PRV....simple check valve only---Glycol system for heating.

I am thinking of dual check vented BFP (non testable) for all 4 CW feeds.
For B, would the snap action of the electric valve produce enough water hammer to cause problems? I was thinking of adding sealed air chamber arrestor.

Then do they all have to be low lead?? They are fed by the potable cold soft water system for the building.


  • Jamie Hall
    Jamie Hall Member Posts: 23,527
    Um. Well, back in the day, @JUGHNE , I'd have made you put testable RPZ backflow preventers on them. I was a rather conservative building inspector... mellowed some (?) with age! But I'd still like to see one at the very least on the hydronic with glycol.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • MikeJ
    MikeJ Member Posts: 103
    I have to say testable :)
    JUGHNE Member Posts: 11,086
    edited December 2017
    So having met with the local city water guy who had the state water instructor with him, they said testable.

    So one 1 1/4" testable back flow preventer in the feed line will cover all 4 items mentioned above.

    In this state (and probably others) requirements and testing requirements vary from town to town. But if the state man decrees then the city man agrees.
    State man did say that the BFV and valve ahead of it would not have to be low lead. (So common sense does exist at the state level).