stainless pipe

[grader]

added secondary air to my boiler this past season, 1.5 inch black pipe reducing to .75 pipe with the holes. the .75 did not take the heat and curled like noodles. what kind of stainless .75 inch pipe do i need that will take the heat? i need 4 pieces 10 inches long threaded on one end and capped on the other. any info on type or links are welcome, thanks.

 

[Corey]

I would think about any stainless you pick up should be fine. I found an old industrial table at the scrap yard which had some legs 1" diameter x .100" thick. Those became my secondary air tubes and they have survived years of orange-hot heat with no apparent damage, deformation or deterioration.

https://www.hearth.com/talk/threads/burnin-orange-tonight.106714/

 

[HoosierHillJack]

Schedule 80 stainless 3/4 would work great but schedule 40 should be sufficient. You should look at junkyards and scrap recyclers because buying it new will be painful on your wallet.

 

[Corey]

While the thicker stuff will work, the thinner pipe adds less thermal mass to the firebox which means you can heat up faster and get into secondary combustion sooner.

Even if you are burning 'continuously', that probably still means a load of wood, burning to coals, another load of wood, etc. So even a 15-20 minute delay getting the secondaries hot, times 3-4 loads per day could mean missing an hour or more of secondary combustion every day.

 

[brenndatomu]

I used 304 stainless, it holds up fine. 316 would be good too, just costs a lil more

 

[grader]

thanks for the feedback. i did some online digging for high heat stainless and came up with 309h or 310h but they want about $100.00 a foot for it. if i can use 304 or 316 then it should be cheaper.

 

[brenndatomu]

http://www.onlinemetals.com/ 3/4" x 4' 304 is about $22 plus shipping...this where I got mine