Dwyer PBV - Manual (Page 4)

©Copyright 2012 Dwyer Instruments, Inc. Printed in U.S.A. 8/12 FR# R2-443424-00 Rev. 1
PNEUMATIC ACTUATOR PARTS LIST
1. Extruded aluminum housing
2. Nickel plated steel anti-blowout pinion
3. NBR 70 lower pinion O-ring
◊
4. PTFE pinion spacer ring ◊
5. NBR 70 top pinion O-ring ◊
6. PTFE cam spacer ring ◊
7. SS indicator cam
8. Nylon position indicator
9. SS pinion washer
10. Pinion snap ring
11. Die cast aluminum piston
12. Piston O-ring bushing ◊
13. PTFE antifriction ring ◊
14. PTFE piston thrust block ◊
15. SS stop bolt retaining nut
16. SS stop bolt
17. External spring*
18. Internal spring*
19. Die cast aluminum end cap (left)
20. Die cast aluminum end cap (right)
21. NBR end cap seats
22. SS end cap bolt
*spring return actuators only parts subject to wear. Please contact the factory or
your W.E. Anderson distributor for replacement kits.
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000 www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: 219/872-9057 e-mail: [email protected]
MAINTENANCE
The Series PBV Automated Ball Valves are not field serviceable and should be
returned if repair is needed (field repair should not be attempted and may void
warranty). Be sure to include a brief description of the problem plus any relevant
application notes. Contact customer service to receive a return goods
authorization number before shipping.
PNEUMATIC ACTUATOR
Note: For optimal operation, PBV actuators should be run with a supply of clean,
lubricated air.
SPRING RETURN ACTUATORS
Air to PORT 2 (the right hand port) causes the actuator to turn CCW. Loss of air to
PORT 2 causes air to exhaust and the actuator turns CW. This is the FAIL CLOSE
operation.
DOUBLE ACTING ACTUATORS
Air to PORT 2 (the right hand port) causes the actuator to turn CCW. Air to PORT
1 (the left hand port) causes the actuator to turn CW.
DISASSEMBLING STANDARD ACTUATORS
IMPORTANT: Before beginning disassembly, ensure that the air supply to the
actuator has been disconnected, all accessories have been removed and that the
actuator has been dismounted from the valve.
1. Loosen the end cap fasteners (22) with a wrench (size varies depending on
actuator model). On the spring return actuator, alternate 3 to 5 turns on each
fastener until the springs are completely decompressed. Use caution in
removing the cap since the springs are under load until the fasteners are fully
extended.
2. Remove the pinion snap ring (10) with a lock ring tool. The indicator (7) may
now be removed.
3. Turn the pinion shaft (2) CCW until the pistons are at the full end of travel.
Disengage the pistons (11) from the pinion. (NOTE: Low pressure air--3 to 5
P.S.I. MAXIMUM--might be required to force the pistons completely from the
body.) Note the position of the pistons before removing them from the actuator
body. The part numbers of the pistons are located on the side and should be
right-side up on an actuator with a standard orientation.
4. Remove the pinion through the bottom of the actuator. The actuator is now
completely disassembled. All replacement parts may now be put in. W.E.
Anderson recommends that all wear parts (3, 4, 5, 6, 12, 13, 14) be replaced
before reassembly.
REASSEMBLING STANDARD ACTUATORS
IMPORTANT: Be sure that the actuator surfaces are free of grit and scratches
before reassembling.
1. Apply a light film of grease to all o-rings and the pinion before replacing.
2. Put the pinion (2) back through the actuator with the flats of the pinion shaft
running parallel with the body.
3. When reassembling the actuator, make sure that the piston racks are square to
the actuator body and returned to their original orientation. (NOTE: The normal
operation of all PBV pneumatic actuators is FAIL CLOSED. To change the
orientation to FAIL OPEN, rotate the racks 180º to create a reverse operation.)
4. When replacing springs in a spring return actuator, ensure that the springs are
replaced in their identical position in the end cap from which they were
removed. (NOTE: In some circumstances, you might want to change the
standard 80 pound spring set to fit your application and available air pressure.
Changing the spring sets on PBV pneumatic actuators requires no special
tools. Please refer to the spring combination torque chart in our catalog for the
inner and outer spring combinations that will allow you to operate with the
spring set that you desire.)
4. Seal the end caps with a petroleum lubricant and bolt to actuator body.
5. Check the seal of the actuator by covering seal areas (pinion, end caps) with
soapy water and using low pressure air to the actuator to ensure that no
bubbles are produced.