restrained joint for concrete to steel pipe 1

[Daamz]

HI,
I was wondering what the usual procedure (if any) was to connect a 72" concrete pipe to a 72" steel pipe? I looked online but didn't find any reatrained joints that would do the trick...

 

[dicksewerrat]

Is this a pressurized system?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[rconner]

If the comncrete pipe is a Carnegie joint type system such as prestressed concrete cylinder pipe (PCCP), I have been told by a quite experienced fellow from American SpiralWeld that the normal procedure is to weld a cylinder to the steel pipe that matches the joint diameter of the PCCP, either by sliding over the spigot or inserting into the bell of the PCCP etc. They or other large diameter pipe manufacturer could be consulted for further advise, if needed. If there is concern over (unknown) which type of pipe is extant/existing, the cylinder would be set for a bell insertion and include a butt strap for a spigot. The cylinder (or butt strap) is then welded to the PCCP steel joint ring.

 

[rossmail]

you can use a rubber coupling with an adapter that when on the steel pipe matches the od of the conc pipe,its a poor method,very week joint,poor shear strength even if a shear band is used ,or use a construction joint (line them up and form the inside with plywood and pour concrete diaper around the joint-the preferred method)

 

[rossmail]

oh i see reatrained joint ,,no why ?the short concrete pipes dont have restrained joints so why restrain the steel to concrete??

 

[BarryEng]

I would not use a restrained joint.
Why not just use a Straub coupling? They can be purchased in SS up to about 2200 mm diameter. These joints are very good as they can take a small axial movement, a small rotation BUT ARE NOT VERY GOOD IF THE ENDS OF THE PIPES CAN MOVE LATERALLY (one pipe not in alignment with the other). They can be used if the pipe ends are up to about 60 or 70 mm apart.

Barry Eng