High Density Polyethylene pipe transition
High Density Polyethylene pipe transition
(OP)
I have a question about transitioning from HDPE pipe to steel pipe. I have seen specifications that call for the transition to be above ground and other specifications that call for the transition to be below ground. If any of you have any insights as to why one method would be used over the other, I would appreciate some input.





RE: High Density Polyethylene pipe transition
I am not aware of any technical reason for preference for above ground versus below ground, other than the fact that some types of joints (e.g. bell and spigot) may require soil restraint to keep the joint from pulling apart.
RE: High Density Polyethylene pipe transition
RE: High Density Polyethylene pipe transition
RE: High Density Polyethylene pipe transition
Thank you!!
RE: High Density Polyethylene pipe transition
When making a material transition, respect this expansion force. Use of a thrust collar may be warranted to keep the pipe where you want it to be.....
let us know how you make out...
BobPE
RE: High Density Polyethylene pipe transition
That being said, the temperature sensitivity is something to be concerned about.
There is one other thing you should be aware of when using HDPE in conjunction with carbon steel or other metal pipe. Your transition should probably include a reducer on the metal pipe side. A nominal 8" SDR 9 pipe will have an ID closer to a Std wall 6" pipe than an 8" pipe.
RE: High Density Polyethylene pipe transition
RE: High Density Polyethylene pipe transition
We've used Philips' Performance Pipe for our underground potable water/firewater lines, wastewater, and natural gas lines. I assume this is an installation on private property since it's for your plant. Be sure to check NFPA 24 (Standard for the Installation of Private Fire Service Mains and Their Appurtenances) for a wealth of information.
The Plastics Pipe Institute (www.plasticpipe.org) is also a good source of information for underground installation of HDPE, among other things.
You might want to take a look at Philips' website:
http://www.cpchem.com/enu/performance_pipe.asp
It includes pipe and fitting data sheets, technical bulletins, and (most importantly) their engineering manual, which includes HDPE-to-steel transition information.
Good luck!
Kelly L
RE: High Density Polyethylene pipe transition