Opening of in-service Butterfly valve with broken locking pin
Opening of in-service Butterfly valve with broken locking pin
(OP)
We have a 24" Wafer type butterfly valve installed on the inlet cooling water line of one of the exchangers.A few days back the valve was closed for taking the exchanger out of service for maintenance purpose. After the maintenance we tried to take the exchange back into service by opening the valve, but it was found stuck (jammed). We tried to rotate the spindle by applying a large moment arm (putting a pipe wrench to it) but this resulted in the breaking of pin (used to fasten the spindle with the gate). Subsequently the spindle became free. Now the problem is that for replacing the valve we have to de-pressurize the main cooling water header which will result in the long duration plant outage (which we want to avoid). Can any body advice any solution to opening the gate without de-pressurizing the line?? A quick reply is requested.





RE: Opening of in-service Butterfly valve with broken locking pin
RE: Opening of in-service Butterfly valve with broken locking pin
You could install a 12" "hot tapped" bypass line around it with a new valve, and put the exchanger back in service with a reduced capacity.
Or you could install a stopple up stream of the valve, to isolate, remove and replace the valve.
RE: Opening of in-service Butterfly valve with broken locking pin