PR200 1" pipe vs Sch 40?

[redcoatd]

Hi,

Is there any reason *not* to use PR200 1" pipe vs Schedule 40?

Gives me slightly bigger diameter compared to Sch 40, and I have some already after installing irrigation system.

cheers

David

 

[uncleof6]

PR200, aka SDR21 (PVC SDR 21 PR 200 PVC 1120 TYPE I GRADE 1) is the pipe I use exclusively. There is no reason to prefer sch40 over it. PR200 is the pressure rating @ 200psi, however the pressure rating is irrelevant for our purposes with pressure down around 5 psi. We are dealing with "flow biased" systems, so the larger the inside diameter, the less friction loss, and thus the higher the flow rate.

 

[redcoatd]

great - thanks!

I figured only running 300 gph it would fine

 

[sleepydoc]

PR200 1" pipe vs Sch 40?

Is this just what they sell at Home Despot for irrigation pipe?

 

[uncleof6]

Is this just what they sell at Hope Despot for irrigation pipe?

OK, a brief lesson:

Home Depot sells "class 200" and perhaps "class 125," as well as sch 40 and sch 80 (and abs dwv pipe.)

All these names for PVC pipe are pressure ratings except for those bearing a "schedule" such as sch20 and sch80. The Sch is based on iron pipe dimensions. The rest are the pressure rating, and different ways to arrive at the pressure rating.

Cl 200 (class 200) is rated @ 200 psi. SDR 21 (Standard Dimension Ratio) is rated @ 200 psi. The "21" means the outside diameter is 21x the wall thickness. Hence the higher the SDR rating, the lower the pressure rating, a higher SDR rating, will have a lower Cl rating. (or PR rating...)

We absolutely don't care about the pressure rating of the pipe. However a pipe such as Cl 125 or Cl 160 (*sometimes* sold as "irrigation pipe") will collapse very easily. Cl 200 and Cl 315 are most commonly "irrigation pipe."

Walking into Home Depot and asking for SDR 21 pipe will often result in a blank stare; walking into an irrigation supply and asking for Cl (class) 200 pipe and you will get handed SDR 21.

When picking out pipe at Home Depot, look at the pipe: exactly what the pipe is will be printed along the pipe (of course, what everyone wants to clean off the pipe which is fine ) You don't want class 125 or class 160.

If you enjoy pounding your plumbing with hammers and other heavy objects, you better go with sch 40, just understand there is a point where the smaller SDR 21 will be stronger than larger sch 40 (larger diameters, the wall gets thinner.) If you need a special bend in PVC pipe, then heating up Sch 40 will be very useful; the thinner walled stuff will collapse too easily when bending. Using Sch 80 pipe is just silly, for aquariums however.