Use of HDPE flange connections in buried force main
Use of HDPE flange connections in buried force main
(OP)
Does anyone have experience with buried HDPE force-main flange connections or a suitable design, such as encasement, to protect these joints? The situation is for a 48" and 54" FM project, on steep grades, where it will be difficult to use a fusing machine in the trench. The flange joints are planned to be spaced at 150' - 200' intervals. I want to find an economical way to ensure that the buried flange joints are protected from the starting and stopping of flow.





RE: Use of HDPE flange connections in buried force main
See page 44
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RE: Use of HDPE flange connections in buried force main
RE: Use of HDPE flange connections in buried force main
I was about to invest in one of the Paulin research FEa packages and analyse the behaviour myself when the project changed and i was left with no one to pay the bill. one problem with using FEa to analyse the flange behaviour is the non linear charactristics of the PE and the soil
RE: Use of HDPE flange connections in buried force main
Flanged joints in plastic piping systems are obviously inherently weaker connections, more subject to viscoelastic deformations, and additionally plastic piping systems are subsequently subjected after original installation to much more pronounced thermal, Bourdon, and Poisson etc. effects (that can also in various fashions also load, and/or repetitively load flanged joints). As you are apparently in this case dealing with underground systems, I guess we could throw in imperfect axial support and/or differential settlement as well as any present corrosive or environmental stress cracking agents also into the mix.
I guess these technical realities, along with some third-party accounts I've heard over the years of unexpected or preferential problems in the field with at least some flavors of polyethylene flanged joint connections (I suspect you could readily find more, even published, with a key word web search e.g. http://www