Combustion Air Piping thickness 3

[incorep]

Are there any codes or good engineering practices that would prevent steel air piping for combustion air (maximum design pressure 2 psi) to be sized for Schedule 10 thickness?

Currently the design is using Schedule 40, and as a cost savings measure, can I use schedule 10?

Thanks,

 

[unclesyd]

There is nothing if the line is properly designed and supported. We called them ducts.

We tried some large size Sch 10 CS but switched to Sch 20 due to problems, which I think were vibrations.

Sch 10 CS maybe hard to find except in the very large sizes of which you line probably is. Flanges can be problem. There were 2 suppliers that we used I see if I can find my literature.

 

[Montemayor]

incorep:

UncleSyd is correct. At 2 psig, this is basically an air duct application and Schedule 40 pipe is dead weight, at excess cost, with no positive contribution other than allowing personnel to sit or step on it.

UncleSyd continues his good, practical advice: Schedule 10 is, unfortunately, hard to come by and may cost MORE - due to low demand. In the past, I have resorted to rolling thin plate (3/16") and seam welding my own forced-draft piping on boilers - clamped on rubber hose connection(s) where possible in order to arrest any fan, boiler, or burner vibrations. Since the forced air is clean and free of any contaminants, I refraim from using any flanges or connectors other than the hoses. I never found reason to open up the ducts for inspection or cleaning.

Hope this experience helps.

 

[tommac]

I suggest you look at spiral weld pipe. Yours is a perfect application for it. Naylor Pipe

http://www.naylorpipe.com/front.asp

is one manufacturer.

 

[Montemayor]

tommac:

Great suggestion and even better application. Naylor is the perfect solution, with corresponding elbows and fittings in the event of offsets and extended length. This is probably cheaper and faster than rolling and welding.

 

[Bobfromoh]

It sounds to me like Sch 40 is a minimum thickness that probably comes from the code that controls the equipment design.....but just guessing here?