Tie into 24" Storm Force Main 3

[sdynamic]

The storm drain system from the new development site should be connected to the existing 24" Storm Force Main. What is the most critical point for designing this?

The storm pipe from the new site is 6" (force main as well). There would be some pressure issues at the point of interest. Can I have any suggestion or engineering advice to design this connection?

Thanks in advance!

 

[cvg]

a little more information might be helpful

 

[bimr]

Check with your local highway department (DOT). They will have standard details on line that you can use.

I am not aware of any critical issues in making such a connection.

It is preferable that the force main enters the manhole from the opposite side of the mh from the discharge pipe.

 

[cvg]

it seems that if you are connecting one force main to another force main, there will not be a manhole, instead it would be a tee or wye fitting of some kind between two pressure pipes. However, the larger implication in my mind is pump station design and backflow prevention. These may be the "pressure issues" that gtg2020 alludes to. There may be a need for a check valve on one of the force mains at this location to prevent backflow. There may also be a need to alter one or both of the pump stations to handle the change in flow and pressure. Thrust restraint should also be considered. Again, if gtg2020 will provide some information, the tips could be addressed to his actual concerns.

 

[civilperson]

Put the connection in a junction box or Manhole for future access. Check the hydralic head at the connection point, have 6" pipe be higher pressure than the 24" pipe. Use isolation valves before/after the junction on both lines to avoid hot tap.

 

[cvg]

if this is storm drainage, I don't see the need for hot tap. I would not schedule the work during the rainy season. wait until the weatherman says no rain. cut out and install the valves and tees plus thrust block or restrained joints. valve vault would be useful for the check valve or the isolation valve.