Flowserve 10 ACCESS I Worcester Controls - Manual (Page 8)

8 10, 15, 20 ACCESS I and 10-40 Access M 39 Actuators Intrinsically Safe WCAIM2028
On spring-return actuators, the springs may need replacement after
extended duty since springs may fatigue and break. SPRINGS
SHOULD ALWAYS BE REPLACED IN COMPLETE SETS. Spring kits are
available through any authorized Worcester/McCANNA distributor.
SPARE PARTS
The following are recommended spare parts which should be kept on
hand for Series 39 pneumatic actuators:
Repair Kit(s) - Kits contain all necessary seals,
bearings and instructions.
Spring Kit(s) - For spring-return actuators.
TROUBLESHOOTING
BEFORE DISASSEMBLING ACTUATOR FOR ANY REASON, CONSULT
REBUILDING INSTRUCTIONS CONTAINED IN FOLLOWING SECTION.
A. If actuator does not function, check to ascertain:
1. That valve is free to rotate. This can be done as described
above in Manual Operation.
2. That actuator is the correct size.
3. That speed control screws or exhaust ports are not blocked.
4. That correct voltage is supplied to solenoid.
5. That sufficient air supply is available at inlet to control block.
Inlet pressure to control block should be at least 40 psig for
double-acting, 80 psig for spring-return (unless a reduced
spring complement is installed (fewer springs)). When
checking supply pressure, place gage in line at control block
inlet and monitor gage for unexpected pressure drops.
B. If proper voltage and air pressure have been verified and valve is
free, proceed as follows:
1. Turn on signal voltage. Check solenoid for clicking sound.
2. If no sound is detected, remove air pressure and turn off
signal voltage.
a) Carefully unscrew solenoid and solenoid stem from end
cap.
b) Reapply signal voltage and observe solenoid plunger. If it
does not retract, replace solenoid.
3. Manually override control block. If correct operation is not
obtained, replace the control block.
4. If control block and solenoid are operating correctly, proceed
to Section C below.
C. If the actuator functions but exhibits leakage, or power loss
accompanied by leakage, proceed as follows:
1. Check voltage. Voltage must be within 10% of the specified
voltage (low voltage will cause leakage out of the back of the
solenoid and burn out of the coil).
2. Check air supply. Be certain that no sharp air pressure drops
occur as unit is cycled. Loss of air pressure can cause
incomplete shifting of the spool valves, which results in
bypass leakage and substantial actuator torque losses.
3. If air supply and voltage are adequate, proceed as follows:
a) If leak is at solenoid exhaust port, replace the solenoid.
b) If leak occurs at exhaust ports in the block itself, the
trouble will be in either the spool valve in the block, or at
one of the piston seals of the actuator. A leaking piston
seal will usually leak on either cycle.
If the block is replaced and leakage continues from
the exhaust port, remove the actuator from the valve,
disassemble (per Rebuilding Instructions below) and
check the following:
1) Make sure that all internal porting is free and clear of
any obstructions. End caps, guide rods and the piston
with hole are air-transporting components.
NOTE: The most common problem encountered on 39
actuators is the improper replacement of the piston
with hole, relative to seals in end caps. (See Step 5)
2) Make certain that the actuator has lubrication, and
that there is no solidified grease between the pinion
and the piston racks.
a) If actuator has no lubrication, apply generous
amount of a #1 grease.
b) If solidified grease between the pinion and the
piston racks is present, clean, dry, regrease and
reassemble.
3) Verify that actuator pinion shaft and/or pistons are
not bound. If bound, reassemble per Rebuilding
Instructions.
4) If unit exhibits excessive amounts of backlash, check
teeth on piston racks for wear. If worn, replace piston
assemblies.
5) In spring-return actuators, check for misplaced or
broken springs. If springs are broken, check body
bore for scoring.
a) If springs are broken, replace springs. SPRINGS
SHOULD ALWAYS BE REPLACED IN COMPLETE
SETS.
b) If body bore is scored, replace it. Also, replace
piston O-rings (contained in repair kit).
6) If actuator is free, valve is free and control block (if
used) is shifting air properly, reassemble the actuator
and retest. If unit still fails to operate, consult
Flowserve.
REBUILDING INSTRUCTIONS
NOTE: For identification of all numbered parts discussed below,
consult exploded view of actuator.
After actuator has been repaired, mark rebuild label accordingly and
apply to actuator.
Flow Control
Worcester Controls