Loading ...
Sorry, an error occurred while loading the content.

Re: [microhydro] HDPE vs PVC pipe

Expand Messages
  • Hugh Morris
    PVC has a limited fatigue life and can cause problems when there is waterhammer. Hugh ... a! ... -- Hugh W Morris (Mr) Dept of
    Message 1 of 3 , Jul 31, 2003
    View Source
    • 0 Attachment
      PVC has a limited fatigue life and can cause problems when there is
      waterhammer.
      Hugh


      Eric Youngren wrote:
      >
      > Hi Tim,
      >
      > I like the HDPE. It is more durable than PVC and is UV-stable. In my system full burial was not an option due to steep rocky terrain and there is danger of falling trees and large limbs, so HDPE was the only good choice. If you will bury it the whole way PVC might be a cheaper way to go. Poly can also freeze solid without fear of rupture.
      >
      > We put in 260' of 4" HDPE this spring with a workshop group. We started with a stack of 20' sections at the top of the hill and pulled the pipe down the hill as we butt-welded each section on. It is very steep so it was helpful to have lots of people to hold the pipe from sliding away down the mountain. The "fusion butt-welder" machine was rented from the pipe supplier for about $45 a day. It is basically a jig to hold the two ends square while you trim the edges with an electric trimmer, then you use the lever arm to push the ends into an electric heater element until you see a uniform bead of plastic melted all around. At that point you QUICKLY pull out the heater element and slam the ends together with the lever arm and hold them under pressure for a few minutes. Its a pretty simple operation. We read the manual, did one practice weld and we felt like experts. The welds are stronger than the pipe itself. It does raise a bead on the inside of the pipe as well but!
      a!
      > t !
      > the flows you mention it should not introduce too much friction. All in all I think its a great system for connecting penstocks. I can email you photos of our welding set-up if you'd like.
      >
      > I paid about $2/ft for the 4" poly pipe. The flange adaptor to connect to the PVC manifold at the bottom was a bit more spendy, but not too bad.
      >
      > Good luck!
      > Eric
      > ----- Original Message -----
      > From: Tim DiChiara
      > To: microhydro@yahoogroups.com
      > Sent: Thursday, July 24, 2003 9:54 PM
      > Subject: [microhydro] HDPE vs PVC pipe
      >
      > Greetings All:
      >
      > I'm in the beginning stages of researching hydro power for my house in
      > Virginia, USA -- I haven't done the exact measurements yet, but I have
      > approx 30 ft of head and 100-300 gal/min.
      >
      > My question is about piping. I've heard that it's better to use HDPE instead
      > of PVC (I'd probably need 4" inner diameter). However, from what I've read,
      > HDPE pipe needs to be heat-fused ("butt-welded") together, which obviously
      > requires specialized equipment. Is that true? If so, can such a machine be
      > rented at a typical rental store? (And can an amateur operate it?)
      >
      > Also, does anyone know of the approx cost of HDPE pipe per foot? And how
      > about a good supplier/wholesaler?
      >
      > Thanks for a great list!
      >
      > Cheers,
      > Tim
      >
      > _________________________________________________________________
      > MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*.
      > http://join.msn.com/?page=features/virus
      >
      > Yahoo! Groups Sponsor
      > ADVERTISEMENT
      >
      >
      >
      >
      > 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 microhydro-unsubscribe@...
      >
      > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
      >
      > [Non-text portions of this message have been removed]
      >
      >
      > 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 microhydro-unsubscribe@...
      >
      > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

      --
      Hugh W Morris (Mr) <h.morris@...>
      Dept of Civil and Environmental Engineering
      The University of Auckland,
      Private Bag 92019 Auckland NEW ZEALAND

      Ph +64 (9) 3737599 xtn 88186
      Fax +64 (9) 3737462
    Your message has been successfully submitted and would be delivered to recipients shortly.