Mechanical Joint vs. Flanged Joint

[drowles]

Does anyone have a listing of prices for mechanical and flanged joint DI piping for sizes (4"-54")... I realize that there are location adjustments, but I am just trying to get a general idea.. In general, is mechanical joint more or less expensive than flanged joint???

 

[dicksewerrat]

Mech. Joints are normally cheaper to produce and install.

 

[cub3bead]

By mechanical connection do you mean a threaded joint or a Victaulic coupling?

My preference for assebling DI water piping systems is to butt weld everything except where I need to install a a manual valve or a control valve and then it is a flanged connection.

Are you serious about DI water piping as large as 54"?

 

[drowles]

Very serious...

It is for local piping at a water treatment plant.. They prefer DI pipe in that size to concrete pipe...

 

[cub3bead]

My appologies, I misread DI as deionized water not as you obviously intended it to mean ductile iron. Please forgive my error.

 

[cvg]

You may also want to consider steel, cement mortar lined pipe for large plant piping. Never used ductile that large

 

[drowles]

Yeah.. I shouldnt use DI that large.. only up to about 42" from past experiences, but I am not the head hancho in this case.. C'mon guys.. no one has a generic price breakdown.

 

[cvg]

Call your ductile supplier and tell him you are thinking of changing from steel to ductile and need prices. Then call your steel supplier and tell him you are thinking of changing from ductile to steel...

you should get some healthy competition

If you are below ground, I would consider steel with welded joints or bell and spigot if thrust restraint is not an issue. Above ground, flanged is OK but also consider victaulic or dresser couplings.