Isolation joint underground

[FilippoT]

We need to install an isolation joint to separate the underground pipeline from the above ground plat section. Unfortunately not enough space was considered on the abovegorund section therefore currently one of the possible solution is to install the isolation joint underground.
Is there any particular requirement for underground isolation joint installation or it is a common practice?

 

[pennpiper]

FilippoT,
You are faced with a poor original design.
The method you proposed (to install the isolation joint underground) will not work.
How about we try to find another way?
A, After the existing pipe comes above ground, is there a set of Flanges (where an Insulation Gasket sets can be installed) before any branches?

B, After the existing pipe comes above ground, are there branches with Flanges (where an Insulation Gasket sets can be installed) on each branch?

C, In the current underground and above ground portion is there space for digging a large pit for a concrete vault where the isolation flanged set (with insulation gaskets and room for the piping and people) can be installed and then rise up out of the pit to above ground without any more contact with the soil?


Sometimes its possible to do all the right things and still get bad results

 

[LittleInch]

It's not the best idea but can be made to work.

I've seen it where the IJ is located inside a pit or box underground. This is so that
1) you can inspect it for leaks
2) the CP doesn't track around through the ground from one side to the other, especially if the ground is wet.

You also need to remember that the pipe between IJ and the above ground section is not protected by CP so may need additional protection.

So no it is not common practice and an insulating flange kit is a possible solution but these are not without their issues either

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.