Hello, Be very wary of bursting pressure. It is one of those numbers that can be manipulated to mean anything. C900 comes in working pressure ratings of 100, 150, & 200 psi. These are the only numbers you should consider. Now, according to my very rough calculations, you should have about 300 psi working pressure at the bottom of your run. That pretty much elimates C900 for your situation. And, don't forget about surge pressures, which can be 3 times your working pressure. Also, I have found 2 problems with using pvc, but that doesn't deter my using it in some cases. 1) Deer love to poke their hoofs thru it. 2) Rodents love to chew holes in it. Now, if you can find a work around to those two problems, or you are willing to live with occasionally having to replace sections of the run, then go ahead and use it.
Just my 2 cents worth, Lewis Hughes Hughes Micro Corp. --- In [EMAIL PROTECTED], "Eric Youngren" <[EMAIL PROTECTED]> wrote: > Hi folks, > > Well I'm finally getting to the point where I'm ready to place my orders for pipe and fittings for my high-head penstock. > > I've been talking with different pipe suppliers and getting a lot of different, and contradictory, information about the pros and cons of various materials. I thought maybe I'd throw it out there to the list to see what y'all suggest. > > Here's the pipeline details: > Gross head : 650 feet > Design Flow : 200 gpm (varies from 50 - 350 gpm seasonally) > Penstock length : 1500' > Site: Very steep and rugged, forested w/ exposed bedrock in many places, some loose shale > > Based on those parameters we're going to use 4" diameter pipe. I have been thinking of using 160 psi rated HDPE for the first 500' of length because it is relatively easy to install and very durable over time. Below the poly I'll need higher pressure rated pipe. My first thought is steel, using Victaulic couplers to connect the 21' sections. But steel is now close to $5 per foot and I'm not looking forward to hauling all of that heavy pipe up and down the mountain all summer, and steel will eventually rust. I talked to a supplier this morning who highly recommended C900 PVC. It is a bit lighter than steel, rated for 985 psi bursting pressure, and half the price of steel. He also assured me that it is UV stable, impact resistant and will last longer than steel. Another guy I talked to was suggesting ductile iron pipe, which I know little about so far. > > So those seem like my options, steel w/ external couplers, C900 PVC or ductile iron. What do you think? I'm no engineer so I'd love to hear from anybody who sees any obvious or not-so-obvious advantages to one of these materials. > > Thanks, > Eric > > > [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/FGYolB/TM --------------------------------------------------------------------~-> Does your company feature in the microhydro business directory at http://microhydropower.net/directory ? If not, please register free of charge and be exposed to the microhydro community world wide! NOTE: The advertisements in this email are added by Yahoogroups who provides us with free email group services. The microhydro-group does not endorse products or support the advertisements in any way. More information on micro hydropower at http://microhydropower.net To unsubscribe: send empty message to [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/microhydro/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
