Large Check Valves
Large Check Valves
(OP)
We had a 30" wafer check valve fail. After 2 weeks of downtime, we finally found the remains of the flapper and are operational again. To avoid this fun, we are replacing all the valves of the same style. Unfortunately, the 30" and 36" replacements will be too wide, and will require cutting the pipe.
Does anybody know of a company that can custom make 2 wafer check valves of this size? I have some calls out, but so far there are no replies.
Does anybody know of a company that can custom make 2 wafer check valves of this size? I have some calls out, but so far there are no replies.





RE: Large Check Valves
RE: Large Check Valves
RE: Large Check Valves
This will likely be a custom job, so if anyone knows of a company that does work like this, please let me know.
RE: Large Check Valves
I presume these are flanged, since if they were weld ends you would have to cut and rebevel the pipe anyway and you might be able to fit them easier. Or maybe there's a bypass around them or something. Any reason you can't cut in a new valve? Or better yet, any reason you can't repair the old ones? Dumb question after they just caused you 2 wks down time I guess.
If they are guided and heavy disk for pig travel, don't try to replace them with a silly wafer check. The pigs will take them out of action at first bang.
http://virtualpipeline.spaces.msn.com
(A work in progress)
RE: Large Check Valves
RE: Large Check Valves
Noreva make short pattern non slam check valves www.noreva.de. This may solve your space problem and also stop the check valve failures and reduce maintenance on other equipment.
Geoffrey D Stone FIMechE C.Eng;FIEust CP Eng
www.waterhammer.bigblog.com.au
RE: Large Check Valves
And as for the type, everyone here has been calling it a wafer check, and with the 36" one just 4 1/16" thick, they definately aren't full body.
They are used in a natural gas environment, so water hammer isn't a factor. The reason it failed is because the flapper plate (as we have come to call it) was attached to the pivoting bar by 4 bolts. For whatever reason, the bolts weren't welded, lock washered or even loctited in place, so they backed out over the last 7 years. Once one on the end wiggled itself out, the two in the middle sheared at the interface, and the last one bolt put up a good fight before failing.
The new design from Wheatley has a one-piece internal assembly. While this undoubtedly makes for a more reliable valve, it is thicker than the original and this proposes a problem.
Repairing was considered, but since the only logical explanation for this check valve is backup protection for an expander, we opted to replace it in the line without the flapper in order to start up the plant sooner. At the moment it is an orifice plate. At the turnaround this fall we are going to replace it with a functional wafer check, whether we have to cut the pipe or not.