Gate Vavles on Buried Steel Pipe Watermain
Gate Vavles on Buried Steel Pipe Watermain
(OP)
Rather than using DIP, the City is requiring that I use 12" epoxy coated welded steel pipe in one particular area of a project (variety of reasons) for a watermain relocation (public water supply main). There's a need for a gate valve on this welded steel pipe. My question is this: Are there any steel gate valves rated for "buried service" on a potable water system? Or, would I still need to use standard cast or ductile iron body gate valves with transition pieces on each side to go from iron to steel? If I can't use steel pipe for buried application (due to corossion), then would it be okay to do so if the valve was in a chamber and not buried directly in soil? Never had to deal with steel pipe with gate valves on a potable watermain before, so I aplogize for my ignorance. Would appreciate any help / insight you can provide.





RE: Gate Vavles on Buried Steel Pipe Watermain
RE: Gate Vavles on Buried Steel Pipe Watermain
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Gate Vavles on Buried Steel Pipe Watermain
You could use a flanged valve or use mechanical joint with a transition gasket for plain-end steel pipe.
RE: Gate Vavles on Buried Steel Pipe Watermain
RE: Gate Vavles on Buried Steel Pipe Watermain
Alternate suggestion is,
Make two cuts into the existing pipe at a distance apart equal to the valve length + 2 flanges + 2 pipe diameters + gaskets + 2 hairs.
Include two new short lengths of pipe (spool pieces, blue) for fit up, each about a minimum of 1 pipe diameter long plus a bit for final cut.
Bevel the flange ends of the spool and weld the flanges to the spools.
Assemble the spool+ flange, valve and spool + flange and check dimension, marking the field-cut-end of the spool for accurate cutting.
Disassemble, bevel the field-cut-ends of spool pieces and weld-in (red) each spool piece at the field cuts.
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Internal and external coatings will require repair after the tie-in cutting and welding... assuming welded flanges.
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Gate Vavles on Buried Steel Pipe Watermain
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Gate Vavles on Buried Steel Pipe Watermain
Alternative valves could be double ecentric,double flanged handwheel and gear operated butterfly valves, ductile cast iron, epoxy coated, approved for drinking water, approved for burial, with stem extension. Plus: probably longer lifetime than centric discs and gatevalves, lower lifetime cost and not as heavy as gatevalves. Minus: not fully open pipeline for pigging.
RE: Gate Vavles on Buried Steel Pipe Watermain
Steve Wagner
RE: Gate Vavles on Buried Steel Pipe Watermain
RE: Gate Vavles on Buried Steel Pipe Watermain
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Gate Vavles on Buried Steel Pipe Watermain
RE: Gate Vavles on Buried Steel Pipe Watermain
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com