Texas UDS Build Question

Discussion in 'UDS Builds' started by texassmokedr, Mar 9, 2016.

  1. Howdy from North Texas,

    I'm working on my first UDS build and want to know if I can use schedule 40 PVC for my upright inlet pipe with my valve on it. I wasn't going to have a upright pipe; however the thought of bending over has convinced me that I need one. Thanks in advance for any insight!

  2. dirtsailor2003

    dirtsailor2003 Smoking Guru OTBS Member

    Suppose you could. I just bought several 3' lengths of black pipe (threaded ends) from Home Depot for my discada burner. Price wasn't bad. I'd go that route before using PVC.

    I used standard gate valves on mine. I just use key to turn the handles. No bending over, and all three gate valves cost less than one ball valve.
  3. I'd like to see that! I'll compare the pipe prices before I get to that stage, Thanks!
  4. dirtsailor2003

    dirtsailor2003 Smoking Guru OTBS Member

    Here is the gate key that I have. The two prongs fit in the handle. You can also get another style that has a square hub on the end. You remove the handle from the valve and the key goes over the hub. Home Depot and most places that sell irrigation equipment have these keys. You can bend the prongs to fit the holes. If you go with the square hub you need to size the key to the hub on the valve. When I am running lower temps 225-250 I have two valves completely closed and the third partially open.

    The key fits in the larger holes just past the green tag. I have three 3/4" gate valves on my UDS.

    Picture of my charcoal basket with ash pan attached.
  5. dirtsailor2003

    dirtsailor2003 Smoking Guru OTBS Member

    Oh yeah gate key costs $2-$5 bucks here. Would be easy to make one too.
  6. bill1

    bill1 Smoke Blower

    I think the vertical pipes help airflow.  Just like draft forces make hot air rise, gravity makes cold air fall.  So bringing in cold air at the top and letting it fall helps things "move" a bit better than only bringing it in at the bottom.  Of course you can always add more openings if flow is a problem and as temperatures stabilize and your fire builds up you don't need as much flow either.  But if the physics is important to you, I think you want the side vertical pipes.  

    Now as to PVC or not...as long as you have cold air going down and in, you'll probably keep the PVC below its flow (melt) temperature.  So if you have 3 pipes and start with them all open but then valve off two of them, the one you always have lots of cold air flow in could be PVC I suppose.  But the other two still have to handle the conducted heat from the fire at the bottom so would have to be metal.  Since cosmetically, I think you want all the same, you might as well plan on them all being metal.  

    But if the PVC question was just due to being on a tight budget, I'd consider galvanized electrical conduit.  EMT, the thinnest, is very inexpensive.  And I don't believe these side pipes get hot enough to oxidize the zinc and allow it to flake off so I wouldn't worry about health issues but your mileage may vary.  (You can always dip the lowest few inches in paint--if the paint doesn't burn off, certainly the galvanization won't.)  If you're careful, 3/4" EMT will take a normal tapered NPT die, and although the thread isn't particularly strong, it will certainly hold up the side pipe and not leak at these low inlet pressures.  Add a little JB Weld if you want to firm it up even more.  And if you move up to intermediate (IMT) conduit, you'll have no issues at all threading it.

    Addendum: Another possible benefit of the side pipes is it allows you to put your valves up higher, where things are cooler.  You might even be able to use cheap PVC ball valves then.  The savings there will easily pay for the side pipes.  Or instead of valves, make your own air restrictors from steel plate, soup cans, etc.    
    Last edited: Mar 11, 2016
    texassmokedr likes this.
  7. Thanks Guys!  This is a work in progress...  here are pics of my build so far, I will use a Webber lid and I burned out the barrel yesterday.  The only barrel I could find was one without a removable lid.  I had to grind down the edge where it was cut out with a big can opener.  Will post more pics soon. 

  8. . Worked on paint prep this afternoon.

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