HDPE to Steel options

[pipe15]

What is the preferred connection between 24" HDPE and 20" steel.
What is the availability of a 20x32"od reducing flange? Are the available in both weld neck and slip-on?

If not, I guess I would use a set of 24" flanges and then a 24x20 reducer.

(I realize that I will use a 24" flange adapter on the HDPE side)

what does anyone think?
thanks
Mark

 

[BarryEng]

In Australia, one method could be that you would lay the PE with a cut end.
Butt weld a PE flanged/spigot onto the cut end of the PE.
The flange of the PE is usually a stub flange with a steel backing ring (have a look at the PIPA web site in Oz, for the details of a stub flange & backing ring).
Use a flanged fitting on the steel pipe to join.
As you said, using a 24 to 20 reducer. I do not know of the diameter differences in your pipes.

Normally, water utilities do not like to use flanges (buried) if they can avoid it. Another method would be to use a Straub coupling (or a Dresser coupling - I don't know what is available in USA). It would depend on the relative diameters of the two pipes. Straub couplings are not usually used with a diameter difference.

 

[dicksewerrat]

Butt weld a 24 20 HDPE reducer to the HDPE. Weld a Flange to that and weld a flange on the steel.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com