check valve in drinage, & Man hole

[vignesh47]

Is it advisable to provide a check valve in the soil drainage line(PVC)

2. I have a manhole which has soil, drainage and a pressurized line from RO reject and Backwash.
The size of the manhole is 1000mm X 1000mm.
The flow from pressurized line is 7.5 l/sec
The difference between the bottom of inlet to manhole(soil pipe) and top of outlet pipe is 10Cm.
Outlet pipe size is 160mm.
Is this 10cm difference between inlet and outlet enough?

 

[europipe]

Not easy to understand, can you provide a sketch or PID ?

 

[vignesh47]

I have attached a sketch. Kindly take a look at it

 

[bimr]

It is not a good idea to put a check valve in a manhole. The pressure is not enough to keep the valve closed. There is no ability to maintain the check valve.