Jordan Valve Mark 688 Series - Piloted Soft Seat Regulator - Manual (Page 3)

4. Use caution when removing the final two bolts. The
upper case is spring-loaded by the internal return
spring (21).
5. Remove the return springs from the diaphragm plate
(21).
6. Remove the valve stem bolt (31) and seal washer
(27) from the diaphragm assembly.
7. Remove the seal washer (33) from the center of the
diaphragm plate.
8. Lift off the diaphragm plate (20) and remove the
diaphragm (19).
9. Inspect and replace as required by reversing the
above steps.
10. When re-assembling, it is necessary to balance the
lower support plate (11) on top of the valve plug/
stem assembly (8). Make sure the valve stem bolt
engages all parts in the diaphragm assembly before
tightening. Use a new seal washer (17).
11. To tighten the valve stem bolt, hold the outside of
the diaphragm plate to prevent the assembly from
turning while tightening the bolt.
12. Make sure to locate the return springs on the
stamped guides in the diaphragm plate before as-
sembling the upper case.
Main Valve Seats
1. Remove diaphragm as listed above.
2. Remove the actuator nut (7) from the lower case.
3. Lift the lower case assembly off of the bonnet.
4. Remove the 4 body bolts (3).
5. Lift off the bonnet assembly (2) from the main valve
plug / stem assembly (8).
6. Remove the plug / stem and cage (9) from the body
bore. Note - the cage will normally come out with
the plug.
7. Remove the seat assembly and o-ring (25) from the
bore of the body.
8. Separate the plug / stem from the cage.
9. Remove plug -O-ring (30) and seal (27).
10. Clean all parts with a light solvent.
11. Replace o-ring numbers (25), (29), (30), & seal (27).
12. Use a light grease, such as Dow Corning #4 to lubri-
cate all o-rings prior to re-assembly.
13. Place the seat o-ring (30) into the body bore, push-
ing it all the way into the corners of the bore.
14. Place the seat ring (13) on top of the o-ring.
15. Insert a new soft seat (10) into the groove on the
seat ring.
16. Assemble the plug o-ring (30) and seal (27) to the
plug groove. Place an additional amount of grease
on the outside of the seal and carefully insert the
plug / stem into the cage (9) being careful not to
damage the o-ring.
17. Place the cage and plug / stem on top of the seat
assembly in the body.
18. Place a new spacer (12) on top of the cage.
19. Insert the bonnet (2) over the stem and onto the
body.
20. Assemble the 4 body bolts (3) using an even
cross-torquing method. Torque to 75 ft-lbs.
21. Place the packing spring (16), retainer (15), new set
of packing (14), and the packing follower (15) into
the packing bore of the bonnet. Lubricate each
piece of packing upon installation.
22. Place the lower actuator assembly over the bonnet.
Make certain the port on the lower case is orient-
ed to the same side as when it was removed, and
is 90° to the flow direction.
23. Secure the actuator nut (7) to the lower case using
a minimum of 100 ft-lbs or torque.
24. Follow the steps outlined above under “Main Valve
Diaphragm” to finish assembling the actuator.