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Gas Valve Pressure capacity

ChrisL Member Posts: 121
I need to replace a gas valve for an older Weil Mclain J5 Boiler. It is 600k btu, and the gas valve is 1 1/4". I purchased a new Honeywell diaphram gas valve that has a max pressure of 1psi. However, the existing valve has a 1/2 psi max.

Will this be a problem? I can't find any info on requirements for pressure ratings on gas valves, and its something that must be done correctly.


Chris Lober


  • Gary Fereday
    Gary Fereday Member Posts: 427
    That pressure

    1 psi is the maximum that that gas valve will handel. 1/2 psi is ok! The question I think you are asking is will the new valve pass that many btu's of gas. That is a function of the valve inards. The instruction sheet should have a maximum btu rating on it. If it is big enough it should tell you. The pressure is set either in the valve or at a seperate regulator. If your valve has a regulator in it ok. Only one regulator please. bigugh
  • Gary Fereday
    Gary Fereday Member Posts: 427

    That big a unit, may need to comply with a insurance inspection gas train. That is a special gas train (valves etc,) that safetys more than just the normal residence heating application. Careful here to check and see if insurance of the building allows what you are going to do! bigugh
  • Gas Valve

    I do not know what valve you are using but as an example a 1 1/4" Honeywell V88A-1683 will handle 2,100 CFH (approx 2,100,000 BTU's) with max pressure of 1lb. The replacing of a gas valve rated for 1/2 lb is not a problem. What is the number on the valve you are going to put in? I will give you the CFH rating once I have the number of the control.

    What is the number on the old control? If I have that I will cross reference for you to make sure your do not violate an underwriter requirement.
  • ChrisL
    ChrisL Member Posts: 121
    Gas valve going in:

    Thanks Tim,

    Actually, that is the valve I am installing...a Honeywell V88A1683. It is replacing a White Rogers which there's not much info on. Only info on the WR is 1 1/4, 1/2 psi, 24v. As I said, boiler is 600k gross.

    My concern with replacing a 1/2 psi capacity valve with a 1 psi valve is that it might flow more gas if the gas pressure goes above 1/2 psi. Not sure if my logic is correct, but as you know, an oversight on something like this could be catastrophic.

    Also, the flame controller on the boiler is a Honeywell RA890f.


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