stainless exhaust tubing/ fabrication for my tank?

[pybyr]

anyone here in the boiler room in the business of fabricating custom big-diameter stainless exhaust like the diesel truck performance enthusiasts use?

or have any friends in that line of work who'd be friendly to a "renewable mad science project" ?

or know of someone in that trade (stainless exhaust) in/ near central/ northern VT?

I need a 5 foot straight length of either 4 or 5 inch diameter 409 stainless tubing for my "stratification baffle"

I also need a smaller diameter L-shaped piece of 409 stainless to go inside it, for another part of my stratification baffle

thanks!

 

[kabbott]

I have ordered from stainless works before http://www.stainlessworks.net/cart/index.php?cPath=95_96
the tube in the link is 304 I think but they might have 409 to, ain't cheap but neither is your tank so you might as well use it.

 

[Nofossil]

You might try Fab-Tech in Colchester. They make BIG stainless pipes (6' diameter) as well as a lot of smaller stuff. Don't know if they'd be interested, but it doesn't hurt to ask.

Giroux's in Hinesburg also does stainless fabrication, and definitely does small / custom jobs. That's where I got my storage tank.

 

[BrownianHeatingTech]

http://www.onlinemetals.com/merchant.cfm?pid=920&step=4&showunits=inches&id=56&top_cat=0

Any reason you don't want to use PVC? It's a good bit cheaper, and easier to machine. Even if you end up wanting to so stainless on the finished product, you may want to experiment with PVC first.

Joe

 

[pybyr]

http://www.onlinemetals.com/merchant.cfm?pid=920&step=4&showunits=inches&id=56&top_cat=0

Any reason you don't want to use PVC? It's a good bit cheaper, and easier to machine. Even if you end up wanting to so stainless on the finished product, you may want to experiment with PVC first.

Joe

actually, I originally wanted to use 4 inch Schedule 80 PVC conduit, precisely for the reasons that you mention (a lot easier to join and drill/ machine) but all the data I was seeing was suggesting that PVC starts to lose mechanical rigidity above 140-150F

my old farmhouse cellar ceiling is pretty low height, so if I used PVC and it melted into a floppy mess, it'll be quite the adventure for me to climb in the manway and replace it- so I'd rather do it right the first time than end up replacing it

if anyone can help point me to some hard data to verify that schedule 80 pvc conduit is highly likely to at least retain its basic shape/ form, when immersed in 200+ F water indefinitely, then I'd be delighted to use that

and thanks for the suggestion of online metals- I have bought from them in the past and been pleased; I've just been hoping to find someone local who has a chunk of material on hand

 

[Nofossil]

A non-scientific suggestion:

Take a piece of PVC and immerse it in boiling water for half an hour. Pick it up with pliers and bend it around a bit, then decide if it's strong enough. The derating is for pressurized applications, and I don't think it deteriorates over time. If it doesn't turn into silly putty, I think you'd be OK.

 

[pybyr]

A non-scientific suggestion:

Take a piece of PVC and immerse it in boiling water for half an hour. Pick it up with pliers and bend it around a bit, then decide if it's strong enough. The derating is for pressurized applications, and I don't think it deteriorates over time. If it doesn't turn into silly putty, I think you'd be OK.

what an ! excellent ! idea-- thank you, as I am too busy ordering and assembling parts while trying to heat a big old VT farmhouse in the mean time with a wood cookstove, since I have yanked much of my old system out and not yet completed the new...

I just yanked my crock pot slow cooker out of the cupboard, filled it full of hot water, set it to simmer and put a scrap piece of 2.5 inch sched 80 pvc in it to see what happens overnight, and then to see again when I get home tomorrow.

if, as someone once said, about a nasty little fact killing a beautify theory, then maybe some empirical evidence will prove that the PVC might work for this

thanks Nofo!

 

[DaveBP]

Trevor,
Stovepipe can be had in stainless if you don't need serious mechanical strength. I think I've seen it in McMaster-Carr.
Puppies shredded my copy and I chucked it but I think that's where I've seen it.

 

[pybyr]

A non-scientific suggestion:

Take a piece of PVC and immerse it in boiling water for half an hour. Pick it up with pliers and bend it around a bit, then decide if it's strong enough. The derating is for pressurized applications, and I don't think it deteriorates over time. If it doesn't turn into silly putty, I think you'd be OK.

what an ! excellent ! idea-- thank you, as I am too busy ordering and assembling parts while trying to heat a big old VT farmhouse in the mean time with a wood cookstove, since I have yanked much of my old system out and not yet completed the new...

I just yanked my crock pot slow cooker out of the cupboard, filled it full of hot water, set it to simmer and put a scrap piece of 2.5 inch sched 80 pvc in it to see what happens overnight, and then to see again when I get home tomorrow.

if, as someone once said, about a nasty little fact killing a beautify theory, then maybe some empirical evidence will prove that the PVC might work for this

thanks Nofo!

since I am home with my son who has a stomach virus, I can report on the results of the crackpot-- err-- crockpot PVC test.

Schedule 80 3 inch PVC conduit does indeed get soft enough to be shape-able by hand when immersed for a prolonged time in 200F water. Not silly putty, but soft enough that I have reservations about how well the whole thing (including drilled ports and other things) would retain its form over the long, long run when confronted with the unrelenting pull of gravity

 

[BrownianHeatingTech]

Schedule 80 3 inch PVC conduit does indeed get soft enough to be shape-able by hand when immersed for a prolonged time in 200F water. Not silly putty, but soft enough that I have reservations about how well the whole thing (including drilled ports and other things) would retain its form over the long, long run when confronted with the unrelenting pull of gravity

Try it with Sch 40. And make sure that you have solid PVC, not foam-core.

Joe

 

[pybyr]

Schedule 80 3 inch PVC conduit does indeed get soft enough to be shape-able by hand when immersed for a prolonged time in 200F water. Not silly putty, but soft enough that I have reservations about how well the whole thing (including drilled ports and other things) would retain its form over the long, long run when confronted with the unrelenting pull of gravity

Try it with Sch 40. And make sure that you have solid PVC, not foam-core.

Joe

I used a piece of the thickest-walled stuff (walls nearly 5/16-3/8 inch thick), and it was solid core electric conduit, which is the sturdiest form of PVC that I've encountered, d efinitely not the foam core as is used for underground drains, etc

I wish it'd work but since it got soft enough for me to re-shape the pipe from round to oval cross-section with my fingers, and without any great exertion, I just don't have confidence, based on that test, that it'd avoid sagging or something of the sort if held at temps approaching 200F on a 24/7/365 basis

 

[sdrobertson]

Could you place a stainless steel rod in the pipe to hold it up and prevent dips? Small diameter rod would be cheaper and hold the plastic up and in shape.

 

[BrownianHeatingTech]

I used a piece of the thickest-walled stuff (walls nearly 5/16-3/8 inch thick), and it was solid core electric conduit, which is the sturdiest form of PVC that I've encountered, d efinitely not the foam core as is used for underground drains, etc

I wish it'd work but since it got soft enough for me to re-shape the pipe from round to oval cross-section with my fingers, and without any great exertion, I just don't have confidence, based on that test, that it'd avoid sagging or something of the sort if held at temps approaching 200F on a 24/7/365 basis

As I said, use the PVC for experimental purposes, before you start cutting on an expensive piece of stainless. Not for permanent use.

Joe