I tried 14 different wholesalers for pipe in my area. Not one carries the
6" PVC S&D 2379 (thin wall inexpensive pipe). SOme said they could order
it. Most had 6" SDR-35 which is about $2.50/ft.

So my options are down to using the metal ventilation 6" pipe ($1.40ft at
Lowes) but I hear the adapters are very expensive....or.......

Keep all ducting at 4" PVC thin walled ($0.58 at Lowes).

"trs80" wrote in message
...
Would a small shop DC system run ok with the mains at 4" smooth bore PVC
ducting vs 6"? I would have about 30' of main and 4 drops using a 2hp
1600cfm unit and air blocks for the station no used. The DC has a 5"
intake and 12" impeller.

I cannot find locally PVC 6" sewer and drain pipe. I can find galvanized
6" duct at about $1.40/ft and 4" smooth bore S&D PVC pipe at $0.58/ft. I
hate to spend more of the duct then the DC which would happen if I go the
metal pipe route.

I visited all local Home supply brands (HD, Lowes, CW) and all dont carry
over 4" pVC. And I called an irrigation supply and they dont carry the
light duty 6" PVC pipe (i think its schedule 2379 or something like that).
Im guessing that its not a big seller inmy area for some reason to do with
building codes for such things.

So any way, I was wondering how much performance I lose by going the 4" vs
6" route.

Any thoughts appreciated!