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Was told my gas line might not be big enough for my Weil Mclain PEG 50 Steam boiler.

BobbyC
BobbyC Member Posts: 96
in Strictly Steam
Gas company was at my house this morning changing my meter and he made a comment that he was surprised the gas line was on 3/4" from the meter to my boiler. I have a WM PEG 50 with an input of 175K BTUs. The run isn't long but I didn't know if I should have a pro look at it. Boiler was installed about 4 years ago. Am I losing in efficiency with that small of a gas line? He sad the pressure was good on the gas. TIA

Comments

  • Abracadabra
    Abracadabra Member Posts: 1,948
    Assuming you are low pressure up to the input of the boiler, 3/4" black pipe is good for about ~190KBTU up to about 20 feet. If you have more than 20' of effective length (including equivalent length for all the fittings) then the line is undersized. Doesn't affect efficiency but firing rate. If you are running the boiler significantly underfired you can run into venting issues.
  • BobbyC
    BobbyC Member Posts: 96
    Thanks Abra. I think I'm under 20 feet but will measure. When you say low pressure up to input what do you mean? How will I know if it's underfired?
  • BobC
    BobC Member Posts: 5,495
    Turn off all the other gas appliances and clock the meter while the boiler is running, that will tell you what the firing rate is. This link will take you to instructions and a handy chart.

    http://www.aprsupply.com/support/technical-support/checking-firing-rate-(clocking-meter)

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Tonski
    Tonski Member Posts: 2
    I had problems recently with my boiler, it was malfunctioning and I didn’t know what to do but then my friend told me about this gasboilerspareparts.com, it helped me a lot, I managed to get the part that was broken in the first place and replace it. Now it is working like never before.
  • Abracadabra
    Abracadabra Member Posts: 1,948
    BobbyC said:

    Thanks Abra. I think I'm under 20 feet but will measure. When you say low pressure up to input what do you mean? How will I know if it's underfired?

    Low pressure gas meaning 6" W.C.

    Don't forget to add the equivalent lengths for elbows/tees/fittings/etc. An elbow is equivalent to 3'? I don't have those memorized.. don't have a cheat sheet handy.

  • BobC
    BobC Member Posts: 5,495
    I just had my gas service upgraded after finding too much pressure drop under load. The old service was dropping 3" when the boiler fired, the new service drops 0.3" when the boiler fires. It took most of the day to dig up the pipe and replace everything up to the gas meter, I'm glad I didn't have to pay for it.

    Have the input gas pressure checked at the boiler with the boiler off and again when it is firing.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • BobbyC
    BobbyC Member Posts: 96
    Alright, so I clocked the meter last night. I counted 40 seconds for it to make one revolution which it stated is 2 cubic feet. So I assume 20 seconds for 1 cubic feet?
  • BobC
    BobC Member Posts: 5,495
    You are correct and that means you are firing at about 180,000 BTU per hour.

    In my case the pipe coming in from the street had deteriorated enough that the ability of the pipe to supply enough gas was compromised.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • BobbyC
    BobbyC Member Posts: 96
    180K per hour good or bad?
  • BobC
    BobC Member Posts: 5,495
    The PEG50 is rated at 175,000 BTU's so you are right where you should be.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • BobbyC
    BobbyC Member Posts: 96
    That's great news. Thanks a lot for the help Bob C!

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