Pressure Sewer Restraint

[EngWade]

All,

How are pressure sewers restrained? Are thrust blocks (similar to potable water distribution systems) an acceptable means for restraining pressure sewers? If not, why not?

Thanks.

 

[bimr]

Pressure sewers are restrained in the same manner as water mains.

Thrust blocks are no longer used as extensively as in the past. Many engineers are moving to the megalug type of mechanical joint restraints.

The system designer has little control over the installation methods used by the Contractors. Thrust blocks may or may not be installed properly by Contractors. There may or may not be problems with the soil conditions as well.

Mechanical restraints are generally more reliably installed.

 

[avane]

In my experiences, thrust blocks are actually quite common even still today. The method depends on the type of pipe material, size and site constraints. It also depends on the pressures expected (remember to count for surge) and the type of bend. Our company has a standard table and detail for blocking based on soil characteristics, angle, and size of pipe. If you're using DIP, go to dipra.org and download the free software. EBAA Iron makes mega-lugs and if you google them, they have a restraint software for various pipe materials. You can also get out a manual and do some calcs.

 

[bimr]

See page 237

http://books.google.com/books?id=SJ...num=10&ved=0CCQQ6AEwCTgo#v=onepage&q=&f=false

http://www.engineeringtoolbox.com/forces-pipe-bends-d_968.html