Wafer valve on HDPE pipe with loose flanges

[arondelo]

Installing a 32" wafer butterfly valve at HDPE pipes with loose flanges would be a problem?

Can anyone share experience regarding this combination (relatively big wafer valve mounted with loose flanges)?

Thanks.

 

[pennpiper]

arondelo,
Please define what you mean by "Loose Flanges".

Sometimes its possible to do all the right things and still get bad results

 

[LittleInch]

I think what you mean is wafer valve between two stub type swivel flanges?

like one of these?

If so then not really. You need to ensure that the valve face is a full face flange face of the same dimensions as the hub part of the connecting flange.

Clearly you need to hold the valve upright when bolting it up and try to get it with zero net torque on the flanges if you can, but they will stand some torque.

More an installation issue with one this big so whatever you use to lift it into place with will need to stay until you finally tighten the bolts up.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[moltenmetal]

Does the valve need to remain in place when you break into the line? If so, you need a lugged body design. Otherwise you can get away with a wafer.

 

[LittleInch]

MM - If the flange has a backing ring though???

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[moltenmetal]

Subject to the dimensional check you've suggested(i.e. making sure that the valve covers the entire flange face of the van stone/lapjoint stub end welded to the pipe) and to the installation caveats you've also pointed out, you should be able to use either a lugged body design or a wafer-style design valve between van stone/lapjoint flanges. Never done this at 32" before but don't know why it wouldn't be possible.

 

[gerhardl]

At such diameters the support of the pipeline, both sides of the valve, to minimize skew forces on valve and pipeline will be of great importance.