Duct Pressure Class higher than 10? 1

[nuuvox000]

I am designing a high velocity exhaust system and my calcs show that the fan motor external static pressure should be 12.5" w.c.. However, in the SMACNA manual I only see pressure classes that go up to 10 or -10. Can I specify a greater pressure class than this? Is there a standard beyond SMACNA for high pressures (or negative pressures)?

 

[Stick.]

Take a look at the SMACNA industrial duct standards (round or rectangular). The tables for skin thickness go up to 1/2" plate, so they'll more than cover the pressures you need (positive or negative). As a caveat, I'll add that my experience is in industrial process equipment and not HVAC, so there may be a better standard than this one, but this is what I'm aware of.

https://www.smacna.org/store/product/round-industrial-duct-construction-standards

https://www.smacna.org/store/product/rectangular-industrial-duct-construction-standards

 

[nuuvox000]

Thank you very much, I was using the HVAC SMACNA Standards Manual which I thought was the only one. Looks like I've crossed over a little into Industrial.