Instruction Manual

Instruction Manual
D100400X012
EWN and EW-1 Valves
July 2014
11
7. Inspect parts for wear or damage that would prevent proper operation of the valve. Replace or repair trim parts
according to the following Lapping Seating Surfaces or Valve Plug Maintenance procedures as appropriate.
Lapping Seating Surfaces
Seating surfaces of the valve plug and seat ring (keys 2 and 9, figure 7 through 10) can be lapped for improved shutoff.
(Deep nicks should be machined out rather than ground out.) Use a commercial lapping compound or a mixture of
600-grit carborundum and solidified vegetable oil.
Assemble the valve to the extent that the cage or cage assembly is in place and the bonnet bolted to the valve. A
simplehandlecanbemadefromapieceofstrapironlockedtothevalveplugstemwithnuts.Rotatethehandle
alternately in each direction to lap the seats. After lapping, remove the bonnet, and clean the seat surfaces.
Completely assemble the valve as described in the Trim Replacement section, and test the valve for shutoff. Repeat
the lapping procedure if leakage is still excessive.
Figure 5. Removal Tool Required for Seat Ring Threaded to Valve Body (also see tables 6 and 7)
FOR136,197,OR203mm(5-3/8,7-3/4,OR8-INCH)SEATRINGS
36A9660-B
B1464
FOR 172 mm (6-3/4 INCH) SEAT RINGS