Water Supply Pipe in Utility Trenches

http://www.dipra.org/pdf/DIPvsHDPE.pdf

(although it is going to be biased towards ductile iron )

THANKS, BUT I ALREADY REFFERED THAT, I AM LOOKING FOR real life EXPERIENCES FROM SOME SENIOR FELLOWS.

I look over and inspect several thousand feet of 36" above ground and below ground water pipe. I have some HDPE water pipe that is not in the ground but most of the 36" and up size is underground. HDPE is great for underground water lines IMO. Most of our above ground water pipe runs through 36" and 30" Sch. 40 SA-53 steel pipe. If you are thinking using HDPE for above ground there are a few things I would suggest.

1. The pipe is going to move allot during the day so it is best to have a support system that allows it to move.

2 Be carefull to fully support under the pipe at required intervals because it will start to sag in between the supports if not. This is really important if it goes over or through an area where it is heated by some other source or if the water inside the pipe is heated. It will sag more the warmer the air or the contents of the pipe gets.

3. If you are considering have long pumped runs of pipe where you could form a vacuum on the pipe when the pumps shut down I would suggest that you install a vacuum breaker every so often in the line. I had some above ground 20" HDPE that had a problem with this.

Good morning naveed.engr. I would highly recommend using the proper HDPE of the appropriate DR for the pressure and temperature involved for your underground piping. I would not bring it above ground, for many reasons. Make the transition below ground to the DI (or steel) pipe. For the underground portion of the DIP, clean and coat the pipe with the proper mastic and tape; and braze the proper anode and cathodic protection checking system to DIP.

The best HDPE pipe is made by Phillips Petroleum, trust me. Be sure to install 6" of fine sand (</= 1/4" dia) bedding prior to installing the HDPE, and 6" of the same cover. Use butt-fusion for your joints. Go have a beer with your girlfriend.

Phillips and Chevron merged their respective pipe groups to form Performance Pipe a division of the Chevron Phillips Chemical Company, Plano, TX, www.driscoplex.com.