I have not "been there done that" but I have seen fitters try to use a flange gasket with wafer valves, which already have a built-in gasket. This creates a rubber-on-rubber seal which does not work well. Yes, sometimes you can get it to seal, but sometimes not. If you feel you need a flange gasket in conjunction with the wafer gasket you should really put a steel washer ring in between so there is rubber-to-metal contact on each side.
If that is not possible due to the tight fit, it may be that you have what the thread title says - misaligned flanges. The fix for that seems like it would be to align the flanges. If this assembly is up in the air at the 9-foot elevation, what is supporting it? It may be that there needs to be more hangers for all that weight to "align" the flanges and get a good seal. John Hoffman P.E. | Fire Protection Engineer | Facility Engineering Services, KCP, LLC - Burns & McDonnell Engineering | National Nuclear Security Administration's Kansas City Plant | Operated by Honeywell FM&T | 2000 E. 95th St | Kansas City, MO 64131 | ph 816-997-7213 | [email protected] From: "Tom Duross" <[email protected]> To: <[email protected]> Date: 02/09/2011 04:20 PM Subject: misaligned flanges Sent by: [email protected] I recently replaced an 8" wafer check on a pump bypass and had a bear of a time doing it. It sits between 2 8" OS&Y gate valves 9' in the air and the whole room is flanged done in 1972. When I took the old one out, the system side valve dropped about 1/8". Plus, I had to use a bottle jack and wedges just to spread it enough to get old out and new in and now I have a drip. I used the same jack to lift the old valve back up and all seemed fine but 2 weeks later; drip, drip. I'm wondering if using double gaskets or maybe those ribbed gaskets might help. It's a Milwaukee 1400 if that helps. Anyone been there done that? TD _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
