How can this check valve function?

Discussion in 'Stove Forum' started by hikerduane, Oct 25, 2023.

  1. hikerduane

    hikerduane Subscriber

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    Having issues with a Coleman 347, alcohol, marine stove. This C/V has a passage below the sealing threads and ends on the top of the C/V. I kept losing pressure of course, so sealed the hole at the top. Now, it is hard to push air into the fount, guess that set up allowed more air to be pumped into the fount, but what would prevent air escaping?
    Or should the "faces" of opposing surfaces make a seal looking at the lower portion of the c/v?
    Duane
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  2. Lantern

    Lantern Subscriber

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    When threaded in place does the lower hole align with anything internally? Hope you can catch my thinking Duane. It is a puzzle. Charlie
     
  3. Toby Garner

    Toby Garner United States Subscriber

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    Duane, as you know Coleman used that same check valve on most of their GPA starting in 1927 till a few years after WW2 minus the hole yours has photoed, with a couple exceptions. On those the sealing surface is the taper below the threads and I suspect yours is the same... The question remains, why the hole of it's above the pressurized fount? I am not familiar with the 347, there may be something there I'm not aware of.
     
  4. hikerduane

    hikerduane Subscriber

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    Was thinking later, if sealed at the taper, air can't go in or out unless there was evidence of a thin, rubber washer to act as it's own C/V. With the aid of my air compressor and a schraeder valve fuel cap, I got higher flames, but after a bit those died down and the burner then produced vapors that burner my eyes and nose, like alcohol will do. Can't get the two burner plates to seal as I get some under burn and the burner gets red, that's when I only get the acrid? vapors.
    I have a new cap coming Friday of the same design, hoping the air stem seals better with it, but that doesn't fix the burner issue.
    Charlie, hard to see that deep into the tube bottom, I'll take a close look.
    Duane
     
  5. hikerduane

    hikerduane Subscriber

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    PS: Pulled the C/V, now I see a hole down low in the internal threads, the male threads on the air stem must provide the seal. Mystery solved, must be enough wear though that the air stem does not stop air escaping. Need to find another air stem I guess.
    Duane
     
  6. Toby Garner

    Toby Garner United States Subscriber

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    There's not a check ball like every other Coleman check valve with an air stem positive shutoff?
     
  7. hikerduane

    hikerduane Subscriber

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    Yes it is, but has the extra passage for air to get pumped to the fount, guessing since it has a large diameter pump. This has three extra holes in it. Will see if a NOS C/V has less wear and the air stem can seal off escaping air.
    Duane
     
  8. Toby Garner

    Toby Garner United States Subscriber

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    Duane, if it's like every other Coleman with that style check valve, that hole on the side will not pressurize the fount. Yours is the only one I've ever seen made with that hole.
     
  9. hikerduane

    hikerduane Subscriber

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    No, with me finding the internal hole and since I sealed the top hole, the pump is much harder to operate now, so I'm finally grasping the reason for the extra passage. The marine stoves are quite a departure from other stoves. Just look at all the parts used for the preheater.
    Duane
     
  10. Toby Garner

    Toby Garner United States Subscriber

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    I understand they're different, but without a check valve and/or NRV on that other hole it can't possibly be to pressurize the fount.... Does anyone have the operating instructions for this model? Maybe there is another passage that extra air is taking going some where else... I've never seen the operating instructions for this model.
     
  11. hikerduane

    hikerduane Subscriber

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    Ah, I follow you now. There is a passage/channel to the top as it would have to be, just under the threads, running to the hole I plugged at the top.
    I found some operating instructions linked by Berniedawg. No mention of this type C/V.
    Duane
    found.
    PS: I notice a discrepancy with dual numbers for the C/V. Transposed number?
    https://www.berniedawg.com/wp-conte...man-348-Marine-Alcohol-Stove-Instructions.pdf
     
    Last edited: Oct 25, 2023