Emerson Fisher OS2 Instruction Manual page 12

Type OS2
COUPLING (KEY 5L)
COUPLING
HEAD
(KEY 5M)
W6853_1
Figure 9. Equalizer Bypass and Coupling Assembly for
NPS 1 through 6 / DN 25 through 150 Body Sizes
Disassembly of the Valve Plug (if required)
(Refer to Figure 13)
1. Remove the square nut (key 53).
2. Remove the small stem bushing (key 24).
3. Extract the bonnet (key 15) / valve cylinder (key 14).
Normally, the bonnet (key 15) / valve cylinder
(key 14) part cannot be dismantled.
4. Remove the main spring (key 12).
5. Remove the screws (key 36) and fixing O-ring (key 34)
while the pin (key 35) remains mounted on the valve
plug body (key 13A).
Disassembly of the Valve Plug O-ring
(if required) (Refer to Figure 13)
1. The valve plug body (key 13A) is threaded to the
valve plug cylinder (key 13B), the O-ring (key 34) can
be reached by unscrewing the valve plug assembly
(keys 13A and 13B) using a bar of 800 and 4 screws
[2 M8 on valve plug cylinder (key 13B) and 2 M10 on
valve plug body (key 13A)].
Assembly for NPS 1 through 6 / DN 25 through
150 Body Sizes (Refer to Figure 12)
1. Attach a new equalizer bypass (key 5A) to the coupling
(key 5) using a roll pin (key 5K).
2. Screw the equalizer bypass (key 5A) into the valve
plug (key 5H) with the plug disk (key 5N) and a new
plug O-ring (key 5J). Be careful not to nick or pinch the
O-ring (key 5J) when tightening the equalizer bypass
(key 5A). On the NPS 4 and 6 / DN 100 and 150 body
sizes, attach the plug disk (key 5N) and a new plug
O-ring (key 5J) to the valve plug (key 5H) using six
cap screws.
12
EQUALIZER BYPASS
(KEY 5A)
ROLL PINS
(KEY 5K)
Note
COUPLING
HEAD
(KEY 5M)
VALVE PLUG
(KEY 5H)
PLUG O-RING
(KEY 5J)
W6855
Figure 10. Valve Plug (Key 5) and Equalizer Bypass Assembly
for NPS 1 through 6 / DN 25 through 150 Body Sizes
3. Replace the valve piston ring (key 7) on the inside of the
bonnet skirt.
4. Refer to Figures 12 and 15. Place a new O-ring
(key 24B) on the small stem bushing (key 24). Set the
valve plug assembly (key 5) on a hard flat surface.
Set the main spring (key 12) in place on the valve
plug (key 5H). Place the bonnet (key 15) on the spring
(key 12) and compress the spring by pressing down
on the bonnet. Attach the stem (key 24) to the coupling
head of the valve plug (key 5H) through the bonnet
(key 15). Slowly release the bonnet (key 15) to allow
the spring tension to seat the small stem bushing
(key 24) onto the bonnet and carefully place the O-ring
(key 24B).
5. Place the bonnet assembly (key 15) onto the body
(key 1) using a new O-ring (key 10) and a new
external O-ring (key 11). Secure the bonnet (key 15)
by tightening down the nuts (key 23, for NPS 4 and 6 /
DN 100 and 150 only) or cap screws (key 21).
6. Place the mechanism box (key 16) onto the bonnet
(key 15) and attach using two cap screws (key 39) and
two flat washers (key 40).
7. Hook the sliding clevis to the stem and insert the pin
(refer to Figures 7 and 8). Secure the Pinusing the clip.
8. To reset, see Resetting the Trip Mechanism in the
Adjustment section.
Assembly for NPS 8 and 10 / DN 200 and 250
Body Sizes (Refer to Figure 13)
1. Perform the operations described in Disassembly in
reverse order.
2. Replace O-rings at each disassembly.
3. Be careful when removing or replacing the valve
plug assembly (key 13) to avoid damaging the piston
ring (key 7).
HOLES FOR
SPANNER
WRENCH
EQUALIZER
BYPASS (KEY 5A)
VALVE PLUG DISK
(KEY 5N)