3/4 vs 1"

Starting to gather parts and pieces. I have a couple of questions regarding pipe size. I don't remember seein this in the 1st 4900 posts i have read. Is there a big difference in 3/4" vs 1" pipe nipples and ball valves in regards to temp control and airflow? Also ball valve vs gate valve on intake? Thanks for any light ya'll can shine on this subject.
 
All ball valves are not the same. I saw some 3/4" that were about 1/2" on the inside. maybe thats why it was cheaper. You need to look and compare.

I would think a ball valve would allow you to "fine tune" the air flow better.

If I had the extra cash at the time of purchase, I think I would buy 1" valves for the extra flow.
 
Starting to gather parts and pieces. I have a couple of questions regarding pipe size. I don't remember seein this in the 1st 4900 posts i have read. Is there a big difference in 3/4" vs 1" pipe nipples and ball valves in regards to temp control and airflow? Also ball valve vs gate valve on intake? Thanks for any light ya'll can shine on this subject.

My UDS is not finished yet, but I have bought a gate valve instead of a ball valve. Not sure about air flow, but with liquids a ball valve is simply used for on and off, whereas a gate valve is used to control the flow. Probably over thinking it, but we'll see how it goes soon hopefully.

I also like the look of a gate valve more than a ball valve.
 
I used two 3/4 valves and two 1/2 valves, since I already had two of each. I Don't think it matters much...
 
All ball valves are not the same. I saw some 3/4" that were about 1/2" on the inside. maybe thats why it was cheaper. You need to look and compare.

I would think a ball valve would allow you to "fine tune" the air flow better.

If I had the extra cash at the time of purchase, I think I would buy 1" valves for the extra flow.

Yeah I noticed that too while looking at Lowes today that the actual hole through the center was not that big. Definately not 3/4" of course that refers to thread size not flow. The 3/4" PVC had much bigger hole for flow. I guess with the low temps you could use PVC valves especially if a riser pipe is used for intake.
 
i think the 3/4 may be better than the 1" since the adjustments would have more of an impact.
 
^^^ Tom, sorry to be o/t but she emailed the guys and awaiting a response. Shouldn't be a problem since the farm is rather big. They brought us up 2 bushels of each a few months ago.
 
Yeah I noticed that too while looking at Lowes today that the actual hole through the center was not that big. Definately not 3/4" of course that refers to thread size not flow. The 3/4" PVC had much bigger hole for flow. I guess with the low temps you could use PVC valves especially if a riser pipe is used for intake.


Ball valves are sold as full port, half port and even 1/4 port...make sure you have full port or you won't have enough air flow to keep stoked...I have 3, 1 fully closed, 1 fully open and 1 half cracked for 225 deg.
 
Starting to gather parts and pieces. I have a couple of questions regarding pipe size. I don't remember seein this in the 1st 4900 posts i have read. Is there a big difference in 3/4" vs 1" pipe nipples and ball valves in regards to temp control and airflow? Also ball valve vs gate valve on intake? Thanks for any light ya'll can shine on this subject.

If you want to look at calculations, check out this post below. It describes different ways to get roughly the same circular area for intake or exhaust.


I think without question, the average and most common configuration is three 3/4 intakes, with 1 and a half of them open to maintain 225. If you use larger holes, you'll have to figure out what works.. certainly it won't be 1 and a half; it would be less.

What I do now with a new drum I made, is eight 1/2 inch holes, and I leave 3 of them open to maintain 225.. at some point I may open a 4th after several hours. This, however, is directly tied to the CONFIGURATION of my exhaust. If I have just one 2 inch hole in the lid, the draft is stronger. If I add a little pipe to that, it becomes significantly stronger. In my new drum I have another eight 1/2 holes in the lid which adds up to the same circular area as the single 2 inch hole. It creates a very mild draft but adequate to keep the fire going. I like this because I think it keeps the food moist and allows for that yummy flavored smoke to really sink in. Best of all, it does not burn as much fuel to do all this.

And oh by the way, you may ask "if you only use 3 or 4 of the holes, why make 8 of them?"
Because sometimes I like to smoke chicken and turkey at much higher temp. It makes the skin nice and crispy and doesn't take as long. To do that, I would leave all 8 holes open and that lets me sit between 350 and 400.
 
Question regarding exhaust stack, like an exhaust tip on a car.

How do I fit one to the large bung hole? Do I need to weld one on or is there pipe that screws in I can buy? I'm sure the thread is NPS, just not sure how available this thread would be on a pipe.

Any suggestions would be much appreciated. Ideally I'd like to use a chrome exhaust tip.
 
Question regarding exhaust stack, like an exhaust tip on a car.

How do I fit one to the large bung hole? Do I need to weld one on or is there pipe that screws in I can buy? I'm sure the thread is NPS, just not sure how available this thread would be on a pipe.

Any suggestions would be much appreciated. Ideally I'd like to use a chrome exhaust tip.

Welding that is overkill unless you're making something fancy.
I prefer mine more easily removed. I have a 3inch duct piping (very light compared to the iron piping that will fit inside the bung hole). The part of the 3 inch duct piping that would get inserted into another section is a little smaller and you can make it smaller still... that just sits on top covering the small lip of the bung hole that sticks out.

I cut down the pipe to a length of maybe 6 inches which I think is too much. I find myself removing it sometimes and have re-configured my drum since to not need the single 2 inch hole, but smaller and multiple holes.
 
Interesting posts about the ball valve........ever since I got mine installed, I seem to have trouble getting the temps up much over 250* and the last 25* is like forever getting there.

At the time I bought 2 ball valves, I also added elbows, and 2' of pipe rise to another elbow and then the ball valve. Then later I added the third ball valve and just added it on the close pipe nipple. But frankly, ever since I added the ball valves it seems harder to get the higher temps.
 
Personally, and this is just my opinion, I see no need for more than 1 ball valve. I have 3 intake nipples on mine. 2 are just capped and 1 has a full port ball valve. If I want more air, I'll just uncap one nipple and fine tune with the valve.

Basically if 1 fully uncapped is not enough air, I'll just slighly open the valve. I'm just saying that with only 1 valve, there's still the ability for infinite adjustments from all closed to all open.
 
intake venting

I built my UDS with a 1" ball valve and a 1" nipple / cap.

open everything up to bring it to temp, close the cap and fine tune with the ball valve.

Not hot enough? open the cap and tune with the ball valve...

Fatty meats run hotter.... it takes lots of beer er, I mean experience to learn the way around your UDS.

Happy Smokin !
 
I also agree that only one control valve plus a couple of capped nipples will give you infinite adjustments.
As far as reaching operating temps, whether you want to settle at 250 or take it up to 350, you need to find out how many lit coals to start out with for each type of cook. Once you establish that for your particular drum it only takes a few minutes to reach those temps.
 
I have built 5 of these pits and on my latest build I drilled only one hole for intake ventilation, put a t-nipple in it and then attached the hose from an electronic temperature controller to it. Game over. No more fiddling with the ball valve, taking nipple covers on and off, etc. I know it costs a bit more but you don't have to drill as many holes nor do you buy the gate valves which can run up to $25. The electronic temp controllers can be bought for as little as $150 and in my opinion, they are worth it for when you want to put the meat on and go to bed.
 
:clap2:Score! Found a place near Gardendale, Al that has used open top drums unlined that used to hold cooking oil for for $10 ea. Headed to get 2 right now to start my build. 1 for KISS and 1 for future experimenting and mods.
Wish me luck!
 
Found an exhaust stack that screws straight into the bung hole, happy days!!!

Does the length of the exhaust have any effect on temps, for example, does it run hotter with a longer exhaust?
 
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