BETTIS
SERVICE INSTRUCTIONS
DISASSEMBLY & REASSEMBLY
CBM-SR (-M) SERIES
ENGLISH LANGUAGE
SPRING RETURN
PNEUMATIC ACTUATORS
WITH UNIDIRECTIONAL
INTERNAL MANUAL OVERRIDE
PART NUMBER: 074114E
REVISION: "B"
DATE: December 2001
Bettis P/N 074114E
Revision "B"
Page 1 of 13
CONTENTS
SECTION 1.0 – INTRODUCTION PAGE
1.1 General Service Information ............................................... 2
1.2 Definitions ........................................................................... 2
1.3 General Safety Information ................................................. 3
1.4 Bettis Reference Materials .................................................. 3
1.5 Service Support Items ......................................................... 3
1.6 Lubrication Requirements ................................................... 3
1.7 General Tool Information .................................................... 3
SECTION 2.0 – ACTUATOR DISASSEMBLY
2.1 General Disassembly .......................................................... 4
2.2 Spring Cylinder Disassembly .............................................. 4
2.3 Housing Disassembly ......................................................... 5
SECTION 3.0 – ACTUATOR REASSEMBLY
3.1 General Reassembly .......................................................... 6
3.2 Housing Reassembly .......................................................... 7
3.3 Pneumatic Cylinder Reassembly ........................................ 8
SECTION 4.0 – ACTUATOR SUPPORT INFORMATION
4.1 Testing ................................................................................ 11
4.2 Return To Service .............................................................. 12
4.3 Assembly Tool Drawing 074113 ......................................... 13
SECTION 1 - INTRODUCTION
1.1 GENERAL SERVICE INFORMATION
1.1.1 This service procedure is offered as a guide to enable general maintenance to be performed
on Bettis models CB415M-SR, CB420M-SR, CB520M-SR, CB525M-SR and CB725M-SR
Spring Return Series pneumatic actuators. When the actuator model number has "S" as a
suffix then the actuator is special and may have some differences that are not included in this
procedure.
NOTE: When the actuator model number has "-S" as a suffix then the actuator is special and
may have some differences that may not be included in this procedure.
1.1.2 Normal recommended service interval for this actuator series is five years.
NOTE: Storage time is counted as part of the service interval.
1.1.3 This procedure is applicable with the understanding that all electrical power and pneumatic
pressure has been removed from the actuator.
Bettis P/N 074114E
Revision "B"
Page 2 of 13
1.1.4 Remove all piping and mounted accessories that will interfere with the module(s) that are to
be worked on.
1.1.5 This procedure should only be implemented by a technically competent technician who
should take care to observe good workmanship practices.
1.1.6 Numbers in parentheses, ( ) indicate the bubble number (reference number) used on the
Bettis Assembly Drawing and Actuator Parts List.
1.1.7 When removing seals from seal grooves, use a commercial seal removing tool or a small
screwdriver with sharp corners rounded off.
1.1.8 Use a non-hardening thread sealant on all pipe threads.
CAUTION: Apply the thread sealant per the manufacture's instructions.
1.1.9 Bettis recommends that disassembly of the actuator modules should be done in a clean area
on a workbench.
1.2 DEFINITIONS
WARNING: If not observed, user incurs a high risk of severe damage to actuator and/or fatal
CAUTION: If not observed, user may incur damage to actuator and/or injury to personnel.
NOTE: Advisory and information comments provided to assist maintenance personnel to
injury to personnel.
carry out maintenance procedures.
1.3 GENERAL SAFETY INFORMATION
1.3.1 Products supplied by Bettis, in its "as shipped" condition, are intrinsically safe if the instructions
contained within this Service Instruction are strictly adhered to and executed by well trained,
equipped, prepared and competent personnel.
WARNING: For the protection of personnel working on Bettis actuators, this procedure should
be reviewed and implemented for safe disassembly and reassembly. Close attention
should be noted to the WARNINGS, CAUTIONS and NOTES contained in this
procedure.
WARNING: This procedure should not supersede or replace any customer’s plant safety or work
procedures. If a conflict arises between this procedure and the customer’s
procedures the differences should be resolved in writing between an authorized
customers representative and an authorized Bettis representative.
1.4 BETTIS REFERENCE MATERIALS
1.4.1 CB420M-SR, CB525M-SR Assembly Drawing part number 073530.
Bettis P/N 074114E
Revision "B"
Page 3 of 13
1.4.2 CB415M-SR, CB520M-SR, CB725M-SR Assembly Drawing part number 073743.
1.5 SERVICE SUPPORT ITEMS
1.5.1 Bettis Service Kit.
1.5.2 Commercial leak testing solution.
1.5.3 Non-hardening thread sealant.
1.6 LUBRICATION REQUIREMENTS
1.6.1 The actuator should be re-lubricated at the beginning of each service interval
using the following recommended lubricants.
NOTE: Lubricants other than those listed in steps 1.6.2 should not be used without prior written
approval of Bettis Product Engineering. The lubricant item number on some assembly
drawings is item (5) while the Bettis service kits lubricant item number is item number (500).
1.6.2 All temperature services (-50°F to +350°F)/(-45.5°C to 176.6°C) use Bettis ESL-5 lubricant.
ESL-5 lubricant is contained in the Bettis Module Service Kit in tubes and the tubes are
marked ESL-4,5 & 10 lubricant.
1.7 GENERAL TOOL INFORMATION
1.7.1 All threads on CB series actuators are Inch Unified and NPT.
1.7.2 All tools/Hexagons are American Standard inch. Two adjustable wrenches, small punch,
Allen wrench set, small standard screwdriver with sharp edges rounded off, medium size
standard screwdriver, diagonal cutting pliers, external snap ring pliers, flat file, drive ratchet
/ deepwell socket set and torque wrench (up to 2,000 inch pounds / 226 N-m).
SECTION 2 - ACTUATOR DISASSEMBLY
2.1 GENERAL DISASSEMBLY
WARNING: It is possible, that the actuator may contain a dangerous gas and/or liquids.
Ensure that all proper measures have been taken to prevent exposure or release
of these types of contaminants before commencing any work.
Bettis P/N 074114E
Revision "B"
Page 4 of 13
NOTE: Before starting the general disassembly of the actuator it is a good practice to operate
actuator with the pressure used by the customer to operate the actuator during normal
operation. Notate and record any abnormal symptoms such as jerky or erratic operation.
2.1.1 The setting of the stop screws (2-80) should be checked and setting recorded before stop
screws are loosened or removed.
2.1.2 If not already removed, disconnect all operating pressure from actuator, allowing the spring
to travel to its extended or relaxed position. The spring will rotate to the actuator to its fail
position.
2.1.3 Rotate the handwheel clockwise until the actuator is at the end of its stroke.
2.1.4 Loosen and remove hex nut (2-90) from housing stop screw (2-80).
2.1.5 Remove stop screw (2-80) from housing (1-10).
2.1.6 Loosen and remove hex nut (2-90) from end caps stop screw (2-80).
2.1.7 Remove seal washer (3-80) and thread seal (3-70) from end cap stop screw (2-80). Do not
remove stop screw (2-80) from the end cap (2-20) unless the stop screw needs replacement.
2.2 SPRING CYLINDER DISASSEMBLY
2.2.1 The spring in CBM Series Spring Return Actuators are preloaded. Actuator must be
disassembled in the following manner.
2.2.2 Make sure the handwheel (6-10) is rotated all the way clockwise (relaxing or extending the
spring).
Loading...