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Primary & Secondary LWCO's

RogDog Member Posts: 3
Looking for some feed back on the average distance between the primary pump / boiler low water cut off (MM157) and the secondary manual reset LWCO (MM63M). Application is on a low pressure, 100HP, Burnham Scotch Marine boiler. The factory says their normal setting is 1/2" differrence. I believe this is to close for comfort. We have installed 3 of these boilers in a school and have had multiple shutdowns on the #63. All boilers have been boiled out and skimmed and the water appears to ride pretty even.


  • Joe Billow_6
    Joe Billow_6 Member Posts: 69

    Are you not putting the LWCO on a water column?
  • Tony Furst
    Tony Furst Member Posts: 12

    I have probably 15 of this same boiler installed at various locations and have had no problems with the 1/2" seperation. However what I have found is that if your feedwater supply pressure is not high enough above your operating pressure you can't feed water fast enough to meet the demand and will go off on low water.

    Not sure what pressure you're operating at but if the boilers fall under ASME BPV Section I then your feedwater pressure needs to be 3% above the setting of the largest relief valve opening pressure.

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