Water Cross Restraint Necessary? 3

[Expo-marker]

I am working on designing a subdivision project with a pressurized underground water system. At all Tee's and Reducers we have designed restraints and restraint lengths however, upon city review they have asked us to provide restraints and restraint lengths for the water crosses. This doesn't really make sense to me as the water in the cross isn't changing direction and so it shouldn't need to be restrained. After expressing our confusion to the city reviewer, they have asked us to provide proof that a water cross does not need to be restrained. I have thus far been unable to find anything on the subject and so I was hoping to get some help here.

Project notes: Pipes are all PVC, Fittings are all DIP

 

[77JQX]

One normally installs valves at crosses. Wherever there is a valve, restraint should be included, so the valve may be closed without damage to the system.

 

[ashtree]

The city and 77JQX are correct. In saying that depending upon the design and soil type and a whole range of other factors you may not need any extra restraint, with enough provided by the other pipes and fittings, back fill , trench walls etc.

What the city is asking is for you to demonstrate that you have worked it out not just assumed that things would be okay.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[bimr]

One should consider that at some time in the future, maintenance will be required. Working on one pipe may cause failure of an adjacent pipe.