Hand Valve Maintenance - Emerson ANDERSON GREENWOOD 727 Installation And Maintenance Instructions Manual

ANDERSON GREENWOOD TYPE 727 DUAL PILOT MANIFOLD
INSTALLATION AND MAINTENANCE INSTRUCTIONS

4 HAND VALVE MAINTENANCE

The manifold block hand valves are intended
to function for the life of the valve with no
maintenance. If there is evidence of hand valve
seat leakage, the valve should be removed and
checked for abnormal wear/damage. Damaged
valves should be replaced with new assemblies.
The associated valve seating surface inside the
manifold block should also be examined closely
and resurfaced if required. See Section 12 for
hand valve kits and Section 13 for the special
hand valve seat resurfacing tool.
Hand valve removal (see Figure 5)
1. Remove the lock wire from the hand valve
handle.
2. Loosen the handle bolt (76) and remove
the hand valve handle (75) and hand valve
collar (78) from the valve stem.
3. Remove the latch plates (85) from the
manifold by removing the mounting
bolts (81).
4. Loosen the bushing locknut (72B) on
the top of the hand valve bonnet.
5. Loosen the hand valve bushing (72) to
the top of the valve bonnet.
6. Loosen and unscrew the locking collar
retaining nut (72A) as far as possible and
raise the locking collar (73) above the hex
for the hand valve bonnet. If the locking
collar is difficult to raise, lightly tap the
collar to free it from the manifold. Do not
strike it heavily or grip it with pliers as it
may crush down on the bonnet threads
and be extremely difficult to remove.
7. Loosen and remove the hand valve
assembly from the manifold block.
Hand valve seat resurfacing (see Figure 5)
1. Examine the hand valve seating surface
in the manifold block cavity for signs of
mechanical damage or excessive wear.
2. Recondition the seating surface, if required,
with the special Seat Resurfacing Tool
(Anderson Greenwood Part no. 02.2543.001)
per the included instructions.
WARNING!
Failure to follow these instructions closely may
result in further damage to the seating surface
requiring costly replacement of the entire
manifold block.
3. Remove all chips and debris from the
manifold cavity carefully after reconditioning
the valve seat. Clean, dry compressed air
should be used for this purpose to prevent
debris migration into the manifold's internal
flow passages. The inlet isolation valve
cavity may be cleared by removing fitting
93A, B, C, or D located on the main valve cap
(see Figure 2) and applying a compressed
air jet to the opening. The dome isolation
and vent valve cavities may be cleared by
removing the unloader bushing and piston
assembly (see Section 3 and Figure 4) and
applying compressed air to the opening
located at the bottom of the unloader cavity.
WARNING!
Failure to remove debris thoroughly from the
valve cavities in the manifold block may result
in pilot/main valve damage or malfunction.
4. Replace fitting or reassemble unloader
parts removed in step 3.
13