20
Note
The following step pertains to integral check valve models
only. DO NOT remove check valve parts unless inspection
or unit operation indicates a check valve problem. If
check valve removal is necessary, perform step 8.
8. Select the correct screw listed in Table 7. Obtain a piece
of pipe or tubing with an inside diameter that is slightly
larger than the outside diameter of the seat. Also obtain a
flat washer. Remove seat (17), Figure 16, per instructions
noted in Figure 16. Remove poppet (18), spring (19), and
sleeve (20) from body.
Screw Dia./ Thread Type
Screw Length
1.125–7 UNC–2B
76.2mm (3 in.)
Table 7. Screw Tabulation for Seat Removal
Figure 16. Check Valve Seat Removal
Note
Thread seat (17), then place tubing and washer over
seat area as shown. Thread the screw into seat.
Tighten the screw to remove seat.
Screw
Tubing
Washer
Seat (17)
(Figure 15)
E. Pressure Centered Main Stage Disassembly
(Refer to Figure 17)
1. Remove four screws (1) and name plate (2) from
crossover plate (4).
2. Remove four screws (3) and crossover plate from main
stage body (6).
3. Remove and discard two ‘‘O’’ rings (5) from crossover
plate.
Note
The following section pertains to main stage disassembly. If
your unit does not require main stage disassembly, omit
the following section.
4. Loosen four end cover screws (7) from end cover (8). Be
ready to catch any oil trapped inside the unit. Remove
end cover, spring (10) and discard ‘‘O’’ ring (9).
5. Remove sleeve (11) and piston (12) from main stage
spool (13).
6. Remove main stage spool from body.
7. Remove plug (14) and ‘‘O’’ ring (15) from cover. Discard
‘‘O’’ ring.
Note
Perform step 8 for opposite side cover disassembly. Note
that centering springs are different.
8. Loosen four end cover screws (16) from end cover (17).
Be ready to catch any oil trapped inside the unit. Remove
end cover, spring (19) and centering washer (20).
9. Turn the body on its side and remove plugs (23) and ‘‘O’’
rings (21 and 22) from body. Discard ‘‘O’’ rings.
Note
DO NOT remove the internal plugs of body unless
inspection reveals a problem.
Refer to figures 21 thru 26 for internal plug locations.
10. Remove plugs (25) and ‘‘O’’ rings (24) from body.
Discard ‘‘O’’ rings.
11. If necessary, remove rest pins (28) with vise grip pliers.
