Reinf. Conc. Vault for Flowmeter

[ChipperB]

I need to contruct a concrete vault over an active 30-in PVC C-900 wastewater force main. The flowmeter will be a strap on. My question concerns the pipe/wall penetrations. Because the walls will be poured around the existing force main is it ok for the new concrete to poured dircetly against the pipe or should I make arrangements for there to be some space between the new concrete and the pipe? If a spaace is required, what is a good technique for sealing around the pipe?

thanks

 

[nackra]

http://www.linkseal.com/

I recommend isolating with Link-Seal or comparable system.

Someday the pipe may need to be "fixed"

 

[bimr]

You should use a flexible rubber boot around the pipe. You should think about adding a sump pump since the meter may be ruined by ground water intrusion.

 

[itsleighton]

you can do a precast vault and have the vault manufacturer "doghouse" the penetrations allowing you to lower it over the pipe, then filling the voids on the bottom of the pipe with grout.

http://www.ctprecast.com/Products/images/48_doghouse.gif

 

[cvg]

pre-cast doghouse is the way to go. you should be discussing this with your local pre-caster who can probably answer all your questions.