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Adjustable Pipe through Thimble

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by rexrules, Oct 6, 2012.

  1. rexrules

    rexrules New Member

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    First post here, but I have been reading for a while now.

    Is it acceptable to put a section of Duravent adjustable pipe through a wall thimble? The seam would not be in the wall. Is it ok to trim the collar on the thimble just a little so the adjustable section can fit through?

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  2. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Thimbles shouldn't be modified in any way.
  3. rexrules

    rexrules New Member

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    Is there any acceptable way to pass an adjustable section through the wall?
  4. smwilliamson

    smwilliamson Minister of Fire

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    DO NOT PUT A SEAM OF TWO SECTIONS OF PIPE CONCEALED IN A THIMBLE. Adjustable length often are a tough fit through the thimble because their diameter is exactly the same as the thimble. Adjustable lengths have a slightly larger diameter to accommodate another pipe being inserted into it. as long at the pipe fits through and there is no seam concealed in the wall or ceiling of the thimble...you are fine. Additionally, you should never use more than 1 adjustable length in any straight run and certainly not an adjustable length onto another adjustable length. Try it...they do not slip over each other and do not seal.

    It's okay to trim the thimble if you must but perhaps reconsider your install scenario again. before you get the hole cut in the wall. I find that there is often 1 or 2 acceptable ways to route venting and the first way I come up with may not be the very best one. Dry fit your sections and think it through. However....I will caution you aginst slipping on adjustable lengths until you are fully committed...they are often stubborn to come apart.

    Additionally, when ever you use an adjustable length, you must secure it with 3 screws that WILL NOT PIERCE THE INNER stainless wall. A quick squirt of red RTV in the slip joint is not bad practice either.
  5. rexrules

    rexrules New Member

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    The seams will not be in the thimble. The pipe doesn't seem to want to go through the thimble though. Maybe just a little more force?
  6. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    The venting made by a manufacturer is tested as a system and if you can find a system that has an adjustable section that can be inserted through the thimble for that system without modification the answer would be yes otherwise no.

    You need to see what the manufacturer has to say along with your local code folks, if the wall is made of brick then you likely could get away without even using a pass through thimble.

    An unmodified thimble guarantees that the clearances to combustibles is met for the vent pipe inside the wall. Once again that clearance is vent system specific.

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