Anyone using high temperature silicone 2-ply air duct hose on their roaster?
- CarefreeBuzzBuzz
- Posts: 3874
- Joined: 7 years ago
A product like this:
https://www.pegasusautoracing.com/produ ... viewHeader
Found one North roaster using it on a 1kg machine. I will be getting a 500grm North. At a temp rating of 500 that is more than what I have seen for galvanized steel at 390.
Any thoughts are appreciated.
https://www.pegasusautoracing.com/produ ... viewHeader
Found one North roaster using it on a 1kg machine. I will be getting a 500grm North. At a temp rating of 500 that is more than what I have seen for galvanized steel at 390.
Any thoughts are appreciated.
- millcityroasters
- Posts: 253
- Joined: 10 years ago
We've used it at Roasters Guild Retreat. It's okay for light use, but harder to clean than pipe.CarefreeBuzzBuzz wrote:A product like this:
https://www.pegasusautoracing.com/produ ... viewHeader
Found one North roaster using it on a 1kg machine. I will be getting a 500grm North. At a temp rating of 500 that is more than what I have seen for galvanized steel at 390.
Any thoughts are appreciated.
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- Posts: 340
- Joined: 18 years ago
Not planning on an exhaust fire, but if something were to happen, steel doesn't really ignite. As far as I've googled, silicone will melt and burn although how it does both of those is dependent on flame-retardant additives. If you're using it over a week, I don't think it's gonna catch fire. But on those permanent installations that people sometimes fail to maintain...
Spencer Weber
- CarefreeBuzzBuzz (original poster)
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So I'm confused then. Galvanized steel products I have looked at are rated to 390. For example, Nordfab says this - "At temperatures ranging between 390° F and 480° F, the zinc iron alloy layers in galvanized steel will continue to provide a high level of protection from corrosion. However, there may be some peeling, changes in mechanical properties, and reduction in the corrosion protection. Recommended max. service temperature is 390° F."
Seems to me that at that point, you probably are at a loss too if you have a chaff fire. So I guess it doesn't melt though. The product linked is both silicone and fiberglass.
Your point is well taken in that all the safety steps to avoid a chaff fire in the first place are essential. Right now the flexibility is a real advantage to me as I am not clear where the permanent home will be.
Seems to me that at that point, you probably are at a loss too if you have a chaff fire. So I guess it doesn't melt though. The product linked is both silicone and fiberglass.
Your point is well taken in that all the safety steps to avoid a chaff fire in the first place are essential. Right now the flexibility is a real advantage to me as I am not clear where the permanent home will be.
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The products max service temp and what happens above that temp are separate things. "Needs to be replaced" is one thing. "ignited and burned down my house" is another.CarefreeBuzzBuzz wrote:So I'm confused then. Galvanized steel products I have looked at are rated to 390. For example, Nordfab says this - "At temperatures ranging between 390° F and 480° F, the zinc iron alloy layers in galvanized steel will continue to provide a high level of protection from corrosion. However, there may be some peeling, changes in mechanical properties, and reduction in the corrosion protection. Recommended max. service temperature is 390° F."
Spencer Weber
- CarefreeBuzzBuzz (original poster)
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Spencer thank you for this feedback. I think this has helped me make my decision where I am going to combine some galvanized steel and then use a shorter silicone run until I figure out exact placement and parts needed. After further reading I agree the galvanized won't melt, it may peel. Thank you.
popeye wrote:The products max service temp and what happens above that temp are separate things. "Needs to be replaced" is one thing. "ignited and burned down my house" is another.
- millcityroasters
- Posts: 253
- Joined: 10 years ago
There's no comparison between the two materials.CarefreeBuzzBuzz wrote:So I'm confused then. Galvanized steel products I have looked at are rated to 390. For example, Nordfab says this - "At temperatures ranging between 390° F and 480° F, the zinc iron alloy layers in galvanized steel will continue to provide a high level of protection from corrosion. However, there may be some peeling, changes in mechanical properties, and reduction in the corrosion protection. Recommended max. service temperature is 390° F."
Seems to me that at that point, you probably are at a loss too if you have a chaff fire. So I guess it doesn't melt though. The product linked is both silicone and fiberglass.
Your point is well taken in that all the safety steps to avoid a chaff fire in the first place are essential. Right now the flexibility is a real advantage to me as I am not clear where the permanent home will be.
At 550F the zinc will oxidize and and leave the steel prone to rusting. The pipe itself will be intact. It just might rust someday. In the event of catastrophe, the mechanical properties of steel make it a vastly superior option.
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That peeling is just the galvanized coating. The steel won't melt until well over 1000F. My exhaust air is rarely over 350F leaving the roaster, let alone by the time it goes through the damper and manifold and through the chaff collector and fan before it hits the ductwork. This is primarily due to the increasing airflow as the roast progresses to tame the RoR, purge smoke, and remove chaff, and therefore cooling the exhaust. No peeling at these temperatures. What do you expect your exhaust temperature to be?
LMWDP #581 .......... May your roasts, grinds, and pulls be the best!
- Balthazar_B
- Posts: 1726
- Joined: 18 years ago
Has anyone run stainless steel ductwork for a long-term installation to avoid the eventual deterioration of mild steel as the galvanized zinc coating sacrifices itself?
https://www.ductingsystems.com/ducting-supplies.html
https://www.ductingsystems.com/ducting-supplies.html
- John
LMWDP # 577
LMWDP # 577
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Interesting too that Norfab also says "Nordfab Rigid Flex Steel Hoses have a temperature rating of galvanized steel max. 750° F ... " which seems to contradict their other statement on galvanized steel ratings.
https://www.ductingsystems.com/nordfab- ... -hose.html
https://www.ductingsystems.com/nordfab- ... -hose.html
LMWDP #581 .......... May your roasts, grinds, and pulls be the best!