Bray 98 Series User manual

REVISIONS
REV. ERN#
1 154983
SERIES 98 & 98H
SCOTCH YOKE ACTUATOR
Installation, Operation and Maintenance Manual
BRAY.COM THE HIGH PERFORMANCE COMPANY

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 2 of 84
Table of Contents
1.0 - Definition of Terms 5
1.1 Hazard-free Use 5
2.0 Introduction 5
2.1 Storage 6
3.0 Installation 6
4.0 Operation Guidelines 7
5.0 Assembly Drawing and Materials of Construction 8
5.1 Spring Return Pneumatic Actuator Assembly Drawing and Materials of Construction 8
5.2 Spring Return Hydraulic Actuator Assembly Drawing and Materials of Construction 10
6.0 Maintenance 12
6.1 Lubricants and Maintenance Consumables 12
6.2 Disassembly, Service & Reassembly of Modules 12
6.3 Spring Module 12
6.3.1 Removing the Spring Module 12
6.3.2 Service & Reassembly of the Spring Module 13
6.4 Pressure Module 14
6.4.1 Removing the Pressure Module from Actuator 14
6.4.2 Disassembling the Pneumatic Pressure Module 15
6.4.3 Service & Reassembly of the Pneumatic Pressure Module 15
6.4.4 Disassembling the Hydraulic Pressure Module 16
6.4.5 Service & Reassembly of the Hydraulic Pressure Module 16
6.5 Torque Module 18
6.5.1 Disassembling the Torque Module 18
6.5.2 Service & Reassembly of the Torque Module 18
6.6 Reassembly of Actuator 19
7.0 Field Conversions 20
7.1 Fail Safe Condition (for Spring Return Actuators) 20
7.2 Double Acting to Spring Return 20
7.3 Spring Return to Double Acting 20
8.0 Assembly and Materials of Construction - Double acting single cylinder 22
8.1 Pneumatic Actuator - Double Acting, Single Cylinder Assembly and Materials of Construction 22
8.2 Hydraulic Actuator - Double Acting, Single Cylinder Assembly and Materials of Construction 24
9.0 Assembly and Materials of Construction - Double Acting Dual Cylinder 26
9.1 Pneumatic Actuator - Double Acting, Dual Cylinder Assembly and Materials of Construction 26
9.2 Hydraulic Actuator - Double Acting, Dual Cylinder Assembly and Materials of Construction 28

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 3 of 84
10.0 Bolting Torques and Tools 30
10.1.a S98 Pneumatic Pressure Module 30
10.1.b S98 Pneumatic Pressure Module 30
10.1.c S98H Hydraulic Pressure Module 30
10.2 Torque Module 31
10.3 Spring Module 31
10.4 Actuator Assembly 31
11.0 Technical Data 32
11.1 S98 Double Acting Pneumatic Actuators 32
11.2 S98H Double Acting Hydraulic Actuators 34
11.3 S98 Spring Return Pneumatic Actuators 36
11.4 S98H Spring Return Hydraulic Actuators 40
12.0 Module Weights 44
12.1 Correct Valve Lifting / Strapping 45
13.0 a Series 98 PNEUMATIC Dimensions 46
13.0 b Series 98 HYDRAULIC Dimensions 47
13.1 Series 98/98H Dimensions - Bolting Pattern 48
13.2 Valve Stem Interface Dimensions 48
14.0 Series 98/98H General Specifications and Features 49
14.1 Series 98 Seal Kits And Repair Kits 50
14.2 Series 98H Seal Kits And Repair Kits 52
15.0 Hydraulic Override ON S98 PNEUMATIC ACTUATORS 54
15.1 Installation 54
15.1.1 Installing Hydraulic Override on Spring Return Actuators 54
15.1.2 Operation - Spring Return Hydraulic Override 55
15.2 Installing Hydraulic Override on DA Actuator 55
15.2.1 Operation – DA Hydraulic Override 56
15.3 Maintenance of Hydraulic Override 56
15.3.1 Spring Return Hydraulic Override Cylinder 56
15.3.2 Disassembly of Hydraulic Cylinder 56
15.3.3 Servicing Hydraulic Cylinder 56
15.4 DA Override Cylinder 56
15.4.1 Disassembly of Hydraulic Cylinder 56
15.4.2 Servicing Hydraulic Cylinder 57
15.5 Servicing Hand Pump Unit 57

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 4 of 84
16.0 Jackscrew Override 58
16.1 Installation 58
16.1.1 Installing DA Jackscrew Override 58
16.1.2 Operating DA Jackscrew Override 59
16.2 Installing SR Jackscrew Override 60
16.2.1 Operating SR Jackscrew Override 60
17.0 Extended Stoppers 61
17.1 Installation 61
17.1.1 Installing Extended Stopper for Torque Module 61
17.1.2 Adjusting Extended Stopper 62
17.2 Installing Extended Stopper for Spring Module 62
17.2.1 Adjusting Extended Stopper 62
18.0 Hydraulic Damper 63
18.1 Installing the Hydraulic Damper on a DA actuator 63
18.2 Installing the Hydraulic Damper on SR actuator 65
19.0 Partial Stroke Test & Locking Device 68
19.1 Installing PST &LD on a standard DA actuator 68
19.2 Configuring as a Locking Device to lock at CW end 69
19.3 Configuring as Locking Device at CCW end 71
19.4 Configuring as a Partial Stroke Test Device at CCW end 73
19.5 Configuring as a Partial Stroke Test Device at CW end 73
19.6 Installing PST & LD module on a standard SR actuator 74
19.7 Configuring as a Locking Device to Lock at CW End 76
19.8 Configuring as Locking Device at CCW end 77
19.9 Configuring as a Partial Stroke Test Device at CCW end 79
19.10 Configuring as a Partial Stroke Test Device at CW end 79
20.0 Appendix 80
20.1 Special Requirements for Actuators in Extended Temperature Service 80
20.1.1 Torque Module 80
20.1.2 Spring Module 80
21.0 Reference Drawings 81
22.0 Trouble Shooting Potential Problems 82
For information on this product and other Bray products please visit us at our web page - www.bray.com

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 5 of 84
1.1 Hazard-free Use
This device left the factory in proper condition to be safely
installed and operated in a hazard-free manner. The notes
and warnings in this document must be observed by the user
if this safe condition is to be maintained and hazard-free
operation of the device assured.
• Take all necessary precautions to prevent damage due to
rough handling, impact, or improper storage. Do not use
abrasive compounds to clean, or scrape its surfaces with
any objects.
• Configuration and calibration procedures are described
in this document. Proper configuration and calibration is
required for the safe operation of this product.
• The control system in which the unit is installed must
have proper safeguards to prevent injury to personnel,
or damage to equipment, should failure of system
components occur.
• This document does not cover every detail about every
version of the product described. It cannot take into
account every potential occurrence in installation,
operation, maintenance and use.
• If situations transpire that are not documented in sufficient
detail, please request the required information from the
Bray Distributor or Representative responsible for your area.
1.2 Qualified Personnel
A qualified person in terms of this document is one who is
familiar with the installation, commissioning and operation of
the product and who has appropriate qualifications, such as:
• Is trained in the operation and maintenance of
pneumatic and hydraulic pressure equipment and
systems in accordance with established safety practices.
• Is trained or authorized to energize, de-energize,
ground, tag and lock electrical circuits and equipment in
accordance with established safety practices.
• Is trained in the proper use and care of personal protective
equipment (PPE) in accordance with established safety
practices.
• Is trained in first aid.
• In cases where the device is installed in a potentially
explosive (hazardous) location – is trained in the
operation, commissioning, and maintenance of
equipment in hazardous locations
2.0 INTRODUCTION
The instructions and guidelines in this manual enable
competent technicians to install, operate, adjust and carry out
routine maintenance activities on Series 98 pneumatic and
hydraulic actuators. Responsibility lies with the user to follow
the instructions in this and in any additional documentation
related to the product and accessories supplied with it.
User shall ensure the equipment is installed and operated
in the environment that it is intended for and effective
protections are provided against exposure to pressure and
temperature in excess of maximum rating. Failing to do so
may affect the product warranty. Only trained personnel,
aware of precautions in hazardous environments and health
and safety in the workplace should service the equipment.
Series 98 Scotch Yoke Actuators are designed for quarter
turn rotary valves, in configurations as:
DA- Double Acting with a single cylinder
DD- Double Acting with dual cylinders
SC- Spring Return Fail Close (CW) - Symmetrical and
Canted Yoke
SO- Spring Return Fail Open (CCW) - Symmetrical Yoke
only.
The pneumatic pressure module of the S98 is replaced with a
Read and Follow These Instructions
Save These Instructions
1.0 - DEFINITION OF TERMS
indicates a potentially hazardous situation which, if not avoided, could result in death or serious
injury.
indicates a potentially hazardous situation which, if not avoided, may result in minor or
moderate injury.
NOTICE used without the safety alert symbol indicates a potential situation which, if not avoided, may
result in an undesirable result or state, including property damage.

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 6 of 84
hydraulic pressure module in the S98H, while the Torque and
Spring modules remain the same.
Two output torque characteristic profiles are available in the
form of Symmetrical Yoke and Canted Yoke.
Standard actuators have a mounting base to ISO 5211. MSS
mounting base is available as an option.
Mounting of the shaft driven accessories is per VDE 3845/
NAMUR standard.
The operating pressure range of the Series 98 Pneumatic
Actuators is 40 to 150 psig, and 500 to 3000 psig for Series
98H, depending upon the size and configuration. Refer to
the MOP (maximum operating pressure) charts or the name
plate on the actuator for the maximum operating pressure.
Operating media for S98 pneumatic shall be clean and dry
compressed air, in accordance to ISO 8573-1 Class 2.3.4
filtered to 5 microns or better, with pressure dew point
of -20°C (-4°F) or at least 10°C (18°F) below ambient
temperature.
For S98H hydraulic actuators, operating media shall be the
recommended grade of hydraulic fluid, specified to ISO 4406
class 18/16/13 maximum contamination level and flash point
> 157°C, for the standard temperature trim.
The user shall plan and implement a periodic maintenance
program to ensure the service conditions continue as
intended and the actuator is monitored and maintained per
manufacturer’s recommendations.
2.1 Storage
Bray Series 98 & 98H are not weatherproof until the unit
is properly installed, or all conduits and applicable port
connections are sealed off and prepared for storage. The
units may be shipped with temporary covers to prevent
foreign matter from entering through the conduit openings;
however, the user is responsible for replacing with the proper
sealing plugs to support its NEMA/IP ratings.
To prevent condensation from forming inside the unit,
maintain a near constant external temperature and store
indoors in a well ventilated, clean, dry room. The temperature
shall be between 40°F (4°C) and 85°F (29°C), with a relative
humidity less than 70%. Store units away from vibration
and direct sunlight exposure, and place units on a shelf or
wooden pallet in order to protect against dampness. Keep
units covered to protect against dust and dirt; if storing for
long term, placing the unit inside a plastic sealed bag may be
preferred.
Bray cannot accept responsibility for deterioration caused on-
site once the cover is removed or due to improper storage.
3.0 INSTALLATION
The S98 actuators are assembled, tested and delivered per
the configuration ordered. The mounting of the actuator
may be direct onto the valve or may require a mounting kit
that would include a bracket, coupler shaft with keys and
hardware.
WARNING
Use appropriate tackles and slings to lift the actuator.
Refer to Technical Data table for the approximate actuator
weight. The lifting lugs provided are for lifting the actuator
only and not for lifting the complete valve-actuator-
accessory assembly.
NOTICE
• Actuators do not have any built-in pressure limiting devices.
Such devices must be incorporated in the pressure supply
lines or in the hydraulic power unit as part of the controls
system.
• The user shall ensure installation in intended service
conditions and that the actuator is not covered with
dirt/dust or other substances that may affect any heat
dissipation capability, resulting in exceeding the maximum
temperature rating of the actuator.
• To prolong actuator seal life use only permitted media of
recommended quality.
• The actuator shall not be installed in hazardous areas
incompatible with the defined gas groups and temperature
class.
• When using manual override sandwich gearbox, ensure the
gearbox has over travel at least equal to that of the actuator.
• The actuators can be mounted on valves in different
positions, but care shall be taken to reorient suitably, some
accessories like filter regulation units, hydraulic override
power pack reservoirs, etc. that are gravity dependent for
functioning.
• For extended temperature range service, please refer
to the Special Requirements under Appendix to prepare
the actuator, before proceeding with the below steps on
installation.
Before proceeding with installation, check compatibility of
the valve stem to the actuator bore. The length, size and
configurations (keyways / double D / square) must match.
Additionally, check compatibility of valve and actuator bolting
pattern. If using a mounting kit, physically check the coupler
to ensure it fits the actuator bore and the valve stem.
1. Ensure the pressure module is depressurized completely
by venting the ports of S98 pneumatic actuator to
atmosphere and any power sources to accessories are
disconnected. The S98H hydraulic actuator's cylinder
ports shall be vented into the oil reservoir, through the
direction control valve, in its de-energized state.
2. Ensure the valve and actuator are aligned to the same
position (i.e., valve closed - actuator closed or both in
open). For spring return actuators, align the valve to the

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 7 of 84
fail safe position of the actuator. If a sandwich gearbox
manual override is used, then make sure it is also aligned
with the valve and actuator position.
3. Secure the valve, bolt the mounting bracket to the valve
and fit the coupler shaft on the valve stem (when using
mounting kit). Ensure the actuator's bore and seating
face are clean and coat the valve stem/adaptor with a
suitable oil/grease. Position the actuator to align the
valve stem (or coupler shaft) with the yoke bore and slide
the actuator on until the actuator seats on the bracket
mounting surface (or on the valve top flange, in case of
direct mounting).
4. When using a manual override sandwich gearbox
between the actuator and valve, first couple and fix the
gearbox on the valve following the gearbox installation
procedure. Back off the gearbox travel stop bolts. Mount
the actuator on the gearbox with the coupler shaft and
bolt up the actuator on the gearbox flange.
5. In order to align the bolt holes, it may be necessary to
loosen the valve-bracket bolting slightly. The actuator
mounting bolts should easily thread into the actuator
base without side loading on the bracket (or the valve
top flange). If needed, turn the actuator a bit and/or
adjust the actuator travel stops. Bolt up the actuator
to the bracket / gearbox flange / valve as the case may
be. Refer to the Bolting Torque table for recommended
torque values.
6. Before operating the actuator, disengage the manual
override, if present. The travel stops of the actuator shall
limit the stroke and not those on the gearbox/valve, if
present.
7. Adjust the travel stop bolts of the actuator for the proper
open and closed valve positions, per valve manufacturer’s
recommendations. Refer to the Series 98 specifications
for the travel adjustment range for different models.
8. Tighten the travel stop bolts lock nuts after adjusting the
stop bolts. Ensure the travel stops on gearbox or valve, if
provided, are now adjusted and locked to fractionally lag
the actuator’s stop position.
NOTE: When used for actuating torque seated valves
or swing disc type of valves, ensure that the stop bolt is
sufficiently backed off to permit the valve disc to seat.
9. Ensure the manual overrides are set for the normal
pneumatic operation before putting the actuator to test
in power operation mode. Refer to Sec. 15 through 17.
10. Stroke the actuator a few times at not more than MOP to
check for proper and smooth operation. If the actuator
is equipped with a switchbox or other accessories, adjust
them at this time.
NOTICE
It is recommended to ground the actuator assembly
against any buildup of static electricity.
4.0 OPERATION GUIDELINES
Series 98 actuators operate well in both on-off and
modulating applications. The accessories, control elements,
tubing and fittings shall be chosen for adequate flow rates so
as not to constrict flow or cause high pressure drop affecting
the performance of the actuator.
Maximum Operating Pressure (MOP) of the actuator is
mentioned on the nameplate and shall not be exceeded.
Suitable pressure regulator and safety valve shall be
incorporated in the supply line, if the line pressure is higher
than this.
CAUTION
Do not pressurize from the cap end port of the spring
return actuator. On the pneumatic actuator, this port is
normally fitted with a breather filter. If there is a possibility
of the actuator being submerged temporarily in water
due to flooding, then this port must be provided with an
extension pipe with the breather filter on the pipe end,
at a safe height above the water level. On the hydraulic
SR actuators, tube this port directly to the oil reservoir to
vent it above oil level. To avoid any back pressure, do not
connect it to other return lines.
Spring Return actuators work on pressure stroke or spring
stroke by pressurizing or venting respectively, the adaptor
side port (rod end side). A 3/2 way valve is typically used.
DA models require alternate ports to be pressurized and
vented for stroking. A 5/2 or 5/3 way direction control valve
or two 3/2 way valves may be used.
DD models have adaptor ports of the cylinders tubed in
parallel with the end cap ports of the other side cylinder. The
two cylinders work simultaneously with cap end of one and
rod end of the other pressurized, at a time.
Actuator & Mouting Kit Bolting Torques
Bolt Size Torque
Nm Lb-in
M8 30 265
M12 110 975
M16 260 2300
M20 510 4515
M30 1550 13720
M36 2500 22125

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 8 of 84
CUSTOMER
THIRD ANGLE
PRIMARY UNITS
DIVISION
RELEASED
ERN
REV.
DRAWING NO.
SHEET BTSI Deepak Chandra
08/29/2018
BTSI 184617 ES-00019
1 OF 2 4
GENERAL ASSEMBLY, SERIES 98,
SPRING RETURN PNEUMATIC ACTUATOR
MM
R
A
B
C
D
55
48 51
50
52
2
18
19
47
34
39
40
32 4244
46
49
31
33
26
35 1
25 54
43
56
44
63 63
66
DETAIL A
36 54
DETAIL B
3637
DETAIL C
3838
45 41
DETAIL D
59 57 58
TORQUE MODULE
INTERNAL PARTS
4
11
9
10
8
17
4
21
5
23
22/22a
27
6
5
67
68
69
65
70
20
53
15
16
28
30
29 14
3
7
606162
64
60 61 62
24
12 13
NOTE: REFER SHEET 2 FOR BILL OF MATERIALS
IOM/MANUALS
5.0 ASSEMBLY DRAWING AND MATERIALS OF CONSTRUCTION
5.1 Spring Return Pneumatic Actuator Assembly Drawing and Materials of Construction
For reference only. Please refer to current revision of ES-00019 drawing for more information.

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 9 of 84
For reference only. Please refer to current revision of ES-00019 drawing for more information.
* Parts in Seal Kits
* & ** Parts in Repair Kits
ITEM DESCRIPTION MATERIAL QTY.
1 Yoke Housing Ductile Iron 1
2 Guide Rod Alloy Steel 1
3 Housing Cover Ductile Iron 1
4 ** Bushing (Yoke) PTFE Bronze 2
5 * O-Ring (Yoke) Buna-N 2
6 * O-Ring (Cover) Buna-N 1
7 Top Cover Ductile Iron 1
8 * O-Ring (Top Cover) Buna-N 1
9 ** Flanged Bushing PTFE Bronze 1
10 * O-Ring (Accessory Drive) Buna-N 1
11 Accessory Drive Stainless Steel 1
12 Hex Bolt Steel 8
13 Spring Washer Spring Steel 8
14 Set Screw, Socket Head Steel 2
15 Dowel Pin Hardened Steel 4
16 Socket Head Caps Screw Steel 4
17 Socket Head Caps Screw, Low Head Steel 1
18 Seal Nut Steel 2
19 Stop Bolt Steel 2
20 Breather Vents Carbon Steel 1
21 Yoke Ductile Iron 1
22 ** Slider Block Bronze 2
22A ** Roller Steel 2
23 Yoke Pin Alloy Steel 1
24 Retainer Plate Plastic 2
25 Guide Block Carbon Steel 1
26 ** Bushing (Guide Rod) PTFE Bronze 2
27 ** Bushing (Yoke Pin) PTFE Bronze 2
28 Cap Screw, Flat Head, Hex Socket Steel 8
29 Position Indicator Plastic 1
30 Cap Screw, Flat Head, Hex Socket Steel 1
31 Adaptor, Pressure Module Ductile Iron 1
32 Barrel Carbon Steel 1
33 Piston Ductile Iron 1
34 End Cap, Pressure Module Ductile Iron 1
35 Piston Rod Alloy Steel 1
36 ** Bushing (Adaptor) PTFE Bronze 2
ITEM DESCRIPTION MATERIAL QTY.
37 * Seal, U-Cup Buna-N 1
38 Split Collar Alloy Steel 4
39 Tie Rod Steel 4
40 Locknut, Nylok Steel 4
41 * O-Ring (Piston Rod) Buna-N 1
42 * Wear Ring PTFE 2
43 * Quad Seal Buna-N 1
44 * O-Ring (Barrel) Buna-N 2
45 Retainer Ring Stainless Steel 1
46 Pipe Plug Carbon Steel 1
47 Adaptor, Spring Module Carbon Steel 1
48 Pipe Carbon Steel 1
49 End Cap, Spring Module Carbon Steel 1
50 Spring Guide Carbon Steel 1
51 Button Plastic 9
52 Spring, Compression Alloy Steel 1
53 Lifting Lug Carbon Steel 1
54 Spring Rod Alloy Steel 1
55 End Cover Carbon Steel 1
56 Retainer Ring Stainless Steel 1
57 Spring Washer Spring Steel 4
58 Hex Bolt Steel 4
59 * O-Ring (End Cover) Buna-N 1
60 Stud Steel 12
61 Nut Steel 12
62 Spring Washer Spring Steel 12
63 * O-Ring (Module) Buna-N 2
64 Lifting Eye Bolt Carbon Steel 1
65 Name Plate Stainless Steel 1
66 Breather Vent Stainless Steel 1
67 Label, Logo Metallized
Polyester 2
68 Label, Configuration Metallized
Polyester 1
69 Label, Caution Metallized
Polyester 1
70 Rivets Stainless Steel 4

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 10 of 84
5.2 Spring Return Hydraulic Actuator Assembly Drawing and Materials of Construction
ES-00690
A
B
C
D
55
48 51
50
52
2
18
19
47
72 32
46
49
31
26
35
1
25 54
56
63 63
3373
44 44
39
40
57
34
76
74 74
42
DETAIL A
69
54
DETAIL B
70
3738
36
DETAIL C
45 41 71
DETAIL D
59 57 58
TORQUE MODULE
INTERNAL PARTS
4
11
9
10
8
17
4
21
5
23
22/22a
27
6
5
66
67
65
64
68
20
53
75
79
78
15
16
28
30
29 14
3
7
606162 60 61 62
24
12 13

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 11 of 84
ITEM DESCRIPTION MATERIAL QTY
1 Yoke Housing Ductile Iron 1
2 Guide Rod Alloy Steel 1
3 Housing Cover Ductile Iron 1
4 ** Bushing (Yoke) PTFE Bronze 2
5 * O-Ring (Yoke) Buna-N 2
6 * O-Ring (Cover) Buna-N 1
7 Top Cover Ductile Iron 1
8 * O-Ring (Top Cover) Buna-N 1
9 ** Flanged Bushing PTFE Bronze 1
10 * O-Ring (Accessory Drive) Buna-N 1
11 Accessory Drive Stainless Steel 1
12 Hex Bolt Steel 8
13 Spring Washer Spring Steel 8
14 Set Screw, Socket Head Steel 2
15 Dowel Pin Hardened Steel 4
16 Socket Head Caps Screw Steel 4
17 Socket Head Caps Screw,
Low Head Steel 1
18 Seal Nut Steel 2
19 Stop Bolt Steel 2
20 Breather Vents Carbon Steel 1
21 Yoke Ductile Iron 1
22 ** Slider Block Bronze 2
22a ** Roller Steel 2
23 Yoke Pin Alloy Steel 1
24 Retainer Plate Plastic 2
25 Guide Block Carbon Steel 1
26 ** Bushing (Guide Rod) PTFE Bronze 2
27 ** Bushing (Yoke Pin) PTFE Bronze 2
28 Cap Screw, Flat Head, Hex
Socket Steel 8
29 Position Indicator Plastic 1
30 Cap Screw, Flat Head, Hex
Socket Steel 1
31 Adaptor, Pressure Module Carbon Steel 1
32 Barrel Carbon Steel 1
33 Piston Alloy Steel 1
34 End Cap, Pressure Module Carbon Steel 1
35 Piston Rod Alloy Steel 1
36 * Guide Ring, Piston Rod Phenolic Resin 2
37 * Lip Seal Polyurethane 1
38 * Sealing Set, Piston Rod PTFE & Buna-N 1
39 Tie Rod Alloy Steel 8
ITEM DESCRIPTION MATERIAL QTY
40 Nut, Tie Rod Steel 8
41 * O-Ring (Piston Rod) Buna-N 1
42 * Guide Ring, Piston Phenolic Resin 2
43 * Sealing Set, Piston PTFE & Buna-N 1
44 * O-Ring (Barrel) Buna-N 2
45 Set Screw, Piston Lock Steel 2
46 End Plug Steel 1
47 Adaptor, Spring Module Carbon Steel 1
48 Pipe Carbon Steel 1
49 End Cap, Spring Module Carbon Steel 1
50 Spring Guide Carbon Steel 1
51 Button Plastic 9
52 Spring, Compression Alloy Steel 1
53 Lifting Lug Carbon Steel 1
54 Spring Rod Alloy Steel 1
55 End Cover Carbon Steel 1
56 Retainer Ring Stainless Steel 1
57 Spring Washer Spring Steel 12
58 Hex Bolt Steel 4
59 * O-Ring (End Cover) Buna-N 1
60 Stud / Hex Bolt (Module) Steel 12
61 Nut (Module) Steel 12
62 Spring Washer (Module) Spring Steel 12
63 * O-Ring (Module) Buna-N 2
64 Name Plate Stainless Steel 1
65 Label, Caution Metallized Polyester 1
66 Label, Logo Metallized Polyester 2
67 Label, Configuration Metallized Polyester 1
68 Rivets Stainless Steel 4
69 ** Bushing (Adaptor) PTFE Bronze 1
70 * Wiper Polyurethane 1
71 * Backup Ring (Piston Rod) PTFE 2
72 * O-Ring (End Plug) Buna-N 1
73 * Backup Ring (End Plug) PTFE PTFE 1
74 * Backup Ring (Barrel) PTFE 2
75 Pipe Plug Carbon Steel 4
76 Protective Plug Plastic 2
78 Label, Lifting Metallized Polyester 1
79 Label, Venting Metallized Polyester 1
For reference only. Please refer to current revision of ES-00690 drawing for more information.
* Parts in Seal Kits
* & ** Parts in Repair Kits

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 12 of 84
6.0 MAINTENANCE
Series 98 actuators are designed for long service periods
between maintenance, in demanding conditions. However,
a preventative maintenance program is essential for
ensuring good performance, safe operation, extended life of
equipment and to avoid expensive down time.
The service conditions, load and cycling frequency may vary
largely, which would require the maintenance program to
be suitably designed, with sound judgment of the working
conditions. Contact manufacturer for assistance.
In general, the scheduled service shall include replacement
of all seals and wear parts.
Seals are recommended to be replaced if the actuator is in
storage or inactive for long periods of time to avoid leakage
due to the seal set. Actuators inactive or in storage for >6
months may be checked for leaks firstw.
6.1 Lubricants and Maintenance Consumables
The Standard actuators use the following lubricants, refer
to TS-00084 or contact factory for information on high/low
temperature actuator lubricants.
Shell Alvania EP2 (LF) grease for the Torque & Spring
Modules
Molykote 55 for the Pneumatic Pressure Module.
ISO Grade 32 hydraulic fluid for hydraulic override
Thread lock compound: Loctite 243 (or equivalent)
Thread Sealant: Loctite 577(or equivalent)
Hydraulic fittings thread sealant: Loctite 542 (or equivalent)
Commercial leak check fluid: Snoop (or equivalent)
Anti seize compound: Loctite 77164 (or equivalent)
Hydraulic Fluid for S98H Standard Trim: Mineral Oil, ISO
VG 32 or 46
6.2 Disassembly, Service & Reassembly of Modules
CAUTION
Prior to disassembly of the actuator, disconnect all air/
hydraulic and electrical power from actuator, remove the
relevant accessories from actuator and dismount actuator
from valve (or override gearbox, if present).
NOTICE
Replacement of the press fitted bushings may require
workshop infrastructure to remove the worn bearings
from their housing and to press fit new ones, without
damaging the housings. We recommend sending the
actuator (or module) to our factory for overhauls/major
repairs.
References:
Drawing # ES-00019 – Spring Return Actuator Assembly
Drawing # ES-00020 – DA Assembly
Drawing # ES-00021 – DD Assembly
Drawing # ES-00690 - Spring Return Hydraulic Actuator
Assembly
Drawing # ES-00689 - DD Hydraulic Actuator Assembly
Drawing # ES-00688 - DA Hydraulic Actuator Assembly
(Refer to the Bray website for current revisions of the
drawings)
6.3 Spring Module
WARNING
Follow the sequence of steps as described below. Injury
or damages may occur if critical steps are bypassed or
shortcuts taken.
Never attempt to cut open the Spring Module welded
assembly as the spring inside is energized and can cause
fatal/severe injury or extensive damages.
Note: If the actuator is provided with a jackscrew or
hydraulic override cylinder on the Spring Module, first
ensure to back off the override fully, to unload it from
any spring force. Remove the override assembly before
disassembling Spring Module.
6.3.1 Removing the Spring Module
(Refer to the relevant Spring Return Actuator
Assembly drawing)
1. Slacken the Spring Module side Travel Stop Bolt Lock
Nuts (18) on the torque module (and extended stopper,
if provided). Apply pressure to pressure module adaptor
port (rod end port), raising pressure slowly, enough to
release spring force on the Travel Stop Bolt (19).
2. Mark the set position of the Stop Bolts and back off fully
both the Stop Bolts (and Extended Stopper/Jackscrew, if
present) and release pressure. This will relieve the spring
preload.
CAUTION
Never try to loosen the Spring Rod without completely
relieving the spring load on it.
3. Remove the Extended Stopper/ override assembly, if
present, from the Spring Module by unfastening the
bolts holding the assembly on the End Cap (49).

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 13 of 84
WARNING
The Spring Module is welded into an integral component
and cannot be disassembled.
Spring within is under compression. Never attempt to
modify or cut open this module.
Do not dispose of the spring module in metal scrap unless
it is appropriately disarmed.
4. To take the Spring Module off the actuator, unscrew the
End Cover Bolts (58), remove the End Cover (55) and
the O-ring (59). Using an extended socket spanner /tube
spanner, unscrew and disconnect the Spring Rod (54)
from the Guide Block (25) in Torque Module. A retainer
ring on the threaded side of the Spring Rod stops it
from being taken out of the Spring Module.
5. Sling and support the Spring Module and remove the
Module’s mounting flange Stud Nuts (61) and Lock
washers (62). Spring Module can now be pulled off the
Torque Module. Pull off the module carefully so as not
to damage the threads on the Spring Rod and studs on
the Adaptor.
6.3.2 Service & Reassembly of the Spring Module
Ensure that a correct Repair Kit is on hand, prior to assembly.
1. Take the Retainer Ring (56) off and pull the Spring Rod
out from the cover end.
2. Replace the Bushing (Adaptor) (36), clean and lubricate
the Spring Rod and slide it back in.
3. Install the Retainer Ring back in the Spring Rod groove.
4. Fit the Module back on Torque Module with new O-ring
(63).
5. Thread in the Spring Rod back into the Torque Module's
Guide Block (25) and torque it to value as in Table 10.3.
6. Fit End Cover back with new O-ring (59).

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 14 of 84
6.4 Pressure Module
CAUTION
Ensure the ports are depressurized before disassembly
of Pressure Module. Failure to do so could cause severe
injury.
To take the Pressure Module off the Spring Return
Actuator, first the Spring Module must be removed or
at least the Spring Rod must be disconnected from the
Guide Block (steps 1-4), as described in section 6.3.1.
6.4.1 Removing the Pressure Module from Actuator
1. For Spring return actuators the spring rod shall be first
disconnected following the steps 1-4 of 6.3.1. For
Double acting actuators skip this step.
2. Apply low pressure 5-7 psi on pneumatic or 30-50 psi
on hydraulic actuators to the adaptor port (rod end side
port) to move the piston to end cap side.
3. Depressurize and remove the Plug (46) (or cover plate)
on the End Cap (34). On the S98H, drain out oil from
the ports first, to avoid oil spill.
4. Use an extended socket or tube spanner and unscrew
the Piston Rod (35) from the Guide Block (25) in Torque
Module. Use a square drive or extended hex wrench
(Allen Key) on the hydraulic pressure modules.
5. Sling and support the Pressure Module. Remove the
Adaptor Stud Nuts (61) and Lock washers (62). Pressure
Module can now be pulled off the Torque Module.
Pull off the module carefully so as not to damage the
threads on the Piston Rod and studs on the Adaptor.
6. Ensure the Module sealing O-ring (63) is retained in the
groove.
CUSTOMER
THIRD ANGLE
PRIMARY UNITS
DIVISION
RELEASED
ERN
REV.
DRAWING NO.
SHEET
BTSI Deepak Chandra
08/29/2018
BTSI 184617 ES-00019
1 OF 2 4
GENERAL ASSEMBLY, SERIES 98,
SPRING RETURN PNEUMATIC ACTUATOR
MM
R
A
B
C
D
55
48 51
50
52
2
18
19
47
34
39
40
32 4244
46
49
31
33
26
35 1
25 54
43
56
44
63 63
66
DETAIL A
36 54
DETAIL B
3637
DETAIL C
3838
45 41
DETAIL D
59 57 58
TORQUE MODULE
INTERNAL PARTS
4
11
9
10
8
17
4
21
5
23
22/22a
27
6
5
67
68
69
65
70
20
53
15
16
28
30
29 14
3
7
606162
64
60 61 62
24
12 13
IOM/MANUALS
Pneumatic Pressure Module
CUSTOMER
THIRD ANGLE
PRIMARY UNITS
DIVISION
RELEASED
ERN
REV.
DRAWING NO.
SHEET
BTSI Deepak Chandra
08/29/2018
BTSI 184617 ES-00019
1 OF 2 4
GENERAL ASSEMBLY, SERIES 98,
SPRING RETURN PNEUMATIC ACTUATOR
MM
R
A
B
C
D
55
48 51
50
52
2
18
19
47
34
39
40
32 4244
46
49
31
33
26
35 1
25 54
43
56
44
63 63
66
DETAIL A
36 54
DETAIL B
3637
DETAIL C
3838
45 41
DETAIL D
59 57 58
TORQUE MODULE
INTERNAL PARTS
4
11
9
10
8
17
4
21
5
23
22/22a
27
6
5
67
68
69
65
70
20
53
15
16
28
30
29 14
3
7
606162
64
60 61 62
24
12 13
IOM/MANUALS

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 15 of 84
6.4.2 Disassembling the Pneumatic Pressure Module
1. Secure the Module and unscrew the Tie Rod Nuts (40).
2. Gently tap the End Cap (34) off the cylinder Barrel (32)
with a plastic mallet and remove the End Cap
3. Slide the Barrel over and off the Adaptor (31) and Piston
(33), being careful not to scratch or dent the honed and
chrome plated surface of the barrel.
4. Take the Piston Assembly off the Adaptor, taking care
not to damage the threads.
5. Tie Rods (39) may be unscrewed from the Adaptor Plate.
6. Remove the Retainer Ring (45) and take the Split Collars
(38) off the Piston Rod (35) upper groove. Pull the Piston
Rod off the Piston and remove the Split Collars from the
lower groove.
6.4.3 Service & Reassembly of the Pneumatic Pressure
Module
NOTICE
The wear parts (all seals, piston wear bands and rod
guide bushings in the Repair Kit) shall be replaced during
the maintenance cycle. Ensure the replacement seals are
suitable for the service temperature. Remove old seals
and clean all the parts thoroughly.
The assembly of the Pressure Module is done in vertical
orientation.
Use Dow Corning Molykote 55 lubricant in the
Pneumatic Pressure Module.
1. To reassemble, secure the Adaptor Plate horizontally,
after replacing the Bushing (36), with sufficient space
below, to accommodate the Piston Rod. The rod seal
groove side of the Adaptor faces upwards.
2. Lubricate the piston rod U-cup Seal (37) and insert it in
the groove in Adaptor Plate with the seal lip towards
piston side.
3. Lubricate and install the Adaptor O-ring (44).
4. Lubricate the piston rod O-ring (41) and install in the
groove on the piston rod.
5. Grease and slip in the Split Collars on the Piston Rod
lower groove and slide in the Piston Rod (hex side)
through the Piston till the split collars locate in the
counter bore in the piston.
6. Install the Split Collars on the upper groove similarly and
secure it by the Spiral Retainer Ring.
7. Lubricate the Piston Rod and carefully slide in the Piston
Assembly through the Rod Seal and Bushing in the
Adaptor. Beware of the pinch points between the Piston
and the Adaptor while lowering the Piston Assembly on
the Adaptor inner face.
8. Lubricate and install the Wear Bands (42) and the Piston
Quad Seal (43) on the Piston.
9. Carefully lift and slide in the Barrel over the Piston Wear
Bands, Quad Seal and Adaptor O-ring and push it down
on to the Adaptor.
10. Thread the Tie Rods into the Adaptor, use thread lock
compound on the threads.
11. Lubricate the inside of the Barrel and slide in the End
Cap, aligning the ports on the Adaptor and the End
Cap.
12. Fasten the assembly with Tie Rod Nuts tightened to
the recommended torque. (Refer to Section 10 Bolting
Torque Tables)
13. Lift the Module using lifting eye bolts threaded into the
End Cap and place it horizontally. Put back the Plug/End
Cover on the End Cap to test the module.
14. Apply 10-15 psi air pressure to ports alternately to check
for smooth stroking for 5-10 cycles and then raise to 80
psi and hold the pressure to check for any leaks past the
Piston, through the Rod Seal and the Barrel O-rings.
Leak test the piston seal by bubble test at 80 psi pressure
and for other seals check visually using commercial leak
check fluids (Snoop or equivalent).
Leakage rate after hold down time shall not be much
higher than 1-2 bubbles per minute with a 1⁄4" ID tube.
Stroke the piston a few times to set the seals if leakage
is higher, and repeat the bubble test. If still not within
the limits, dismantle the module to examine the cause.
15. If no abnormalities are seen, the Module is ready for
assembly on the Torque Module.

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 16 of 84
6.4.4 Disassembling the Hydraulic Pressure Module
1. Secure the Module and unscrew the Tie Rod Nuts (40).
2. Gently tap the End Cap (34) off the cylinder Barrel (32)
with a mallet and remove the End Cap.
3. Slide the Barrel over and off the Adaptor (31) and Piston
(33), being careful not to scratch or dent the honed and
chrome plated surface of the barrel.
4. Take the Piston Assembly off the Adaptor, taking care
not to damage the threads.
5. Tie Rods (39) may be unscrewed from the Adaptor Plate.
6. Remove the Lock Screw (45) and unscrew the Piston
(33) off the Piston Rod (35).
7. Pull out all seals, backup rings and wear rings from the
grooves on piston, piston rod, adaptor, end cap and the
end cap plug.
6.4.5 Service & Reassembly of the Hydraulic Pressure
Module
NOTICE
The wear parts (all seals, wiper, piston & rod wear rings
and backup rings in the Seal Kit) shall be replaced during
the maintenance cycle. Ensure the replacement seals are
suitable for the service temperature. Remove old seals
and clean all the parts thoroughly.
The assembly of the Pressure Module is done preferably
in vertical orientation.
Use ISO grade 32 or 46 as lubricant in the Pressure
Module.
1. To reassemble, secure the Adaptor (1) after thorough
cleaning, with sufficient space below to accommodate
the Piston Rod. The wiper seal groove side of the
Adaptor faces upwards.
ES-00690
A
B
C
D
55
48 51
50
52
2
18
19
47
72 32
46
49
31
26
35
1
25 54
56
63 63
3373
44 44
39
40
57
34
76
74 74
42
DETAIL A
69
54
DETAIL B
70
3738
36
DETAIL C
45 41 71
DETAIL D
59 57 58
TORQUE MODULE
INTERNAL PARTS
4
11
9
10
8
17
4
21
5
23
22/22a
27
6
5
66
67
65
64
68
20
53
75
79
78
15
16
28
30
29 14
3
7
606162 60 61 62
24
12 13
Hydraulic Pressure Module

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 17 of 84
2. Lubricate Wear Rings (21), U-cup Rod Seal (17) and the
wiper seal (12) lightly with oil and install them in the
respective grooves with the wear rings inserted first.
3. Flip the Adaptor (1) and install the PTFE Energized Rod
Seal (16) by first lubricating and installing the energizer
O-ring (15) in the seal groove followed by installing the
PTFE seal ring over the O-ring using an appropriate
installation tool. Ensure the PTFE seal is inserted in
the correct direction with the sealing step facing the
hydraulic pressure.
4. Lubricate and install the second Wear Ring (21) in the
bearing groove.
5. Install the scarf cut (split type) PTFE Backup Ring (18) in
the groove on the Header for the cylinder barrel sealing.
6. Lubricate and install the static O-Ring (10) in the groove
with this O-ring on the outside.
7. Similarly, install the scarf cut (split type) PTFE Backup
Ring (24) in the seal groove on the Piston Rod (3).
8. Lubricate and install the O-ring (23) in the groove. Use
a thin walled protective sleeve over threads, to protect
O-ring while assembling.
9. Install the second Backup Ring (24) in the groove, such
that the O-ring (23) is between the two Backup Rings.
10. Thread in the Piston (2) onto the Piston Rod (3) threads
and tighten till the leading piston face loads on the step
or on the circlip.
11. Apply a drop of thread lock compound and thread in
the Set Screw (25) into the tapped hole in Piston’s flat
end and tighten it firmly.
12. Lubricate with oil the energizer O-ring (13) and install in
the piston seal groove. Ensure the O-ring is not twisted.
13. Install the PTFE Seal (14), using appropriate installation
tools.
14. Install the two Wear Rings (20) on the Piston grooves.
15. Carefully guide the Piston Rod’s threaded end through
the Header (1) assembly, ensuring the rod thread do not
damage the seals in the Header.
16. Slide the Piston Rod all the way through, to rest the
Piston face on the Header end.
17. Coat the wear rings and piston seal thinly with oil and
carefully guide the Barrel (4) over the Piston, pushing it
down until it slides over the Header static seal (10&18)
and touches the header body.
18. Thread in the Tie Rods (6) all the way into the tapped
holes on the Header body.
19. Install the PTFE Backup Ring (18) in the End Cap (5)
groove, followed by the O-ring (10) such that the O-ring
is on the outside.
20. Lightly coat the O-ring (10) in the End Cap (5) with oil
and install the end cap through the tie rods onto the
Barrel (4), ensuring the alignment of the ports on end
cap with those on the header.
21. Install the Lock Washers (9) and thread in the Tie Rod
Nuts (8) on the ends of the tie rods and torque them
in cross pattern, refer to Table A1 for tightening torque
values.
22. Install the PTFE Backup Ring (19) on the Plug (7) groove,
followed by O-ring (11) such that the O-ring is on the
threaded side.
23. Thread in the Plug (7) into the End Cap (5) and tighten it
firmly and the module can be then pressure tested.
24. Apply about 1000psi hydraulic pressure to stroke the
piston forward and back a few times. Then raise the
pressure to MOP of the actuator (if higher than 1000psi)
to check for any external leaks. With pressure held on
one port of the cylinder, wait for about 5minutes to
check for any leak through the other port.
25. If no abnormalities are seen, the Module is ready for
assembly on the Torque Module.

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
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6.5 Torque Module
6.5.1 Disassembling the Torque Module
NOTICE
For SR actuators, the Spring Module or the Pressure
Module must be removed from the Torque Module to
allow for removal of the Guide Bar and Yoke Assembly
from the Torque Module.
For DA actuators, remove the end cover on the Torque
Module.
1. Disconnect the Piston Rod (35) and the Spring Rod (54)
from the Guide Block prior to disassembly.
2. Remove the position Indicator (29), if provided.
3. Remove Top Cover Bolts (16) and the Top Cover (7).
4. Take off the Accessory Drive Shaft Assembly (11) from
top of the Yoke.
5. Remove the Housing Cover Bolts (12) and Lock Washers
(13).
6. Tighten the two Set Screws (14) on the Housing Cover
(3), half turn at a time alternately till the Housing Cover
is separated enough to pry off the Housing with a blunt
tool.
7. Gently tap with plastic hammer or pull off the Guide Bar
(2) from the Guide Block (25) and the Housing (1).
8. Rotate and center the Yoke Assembly, move the
Guide Block towards the Yoke center and lift the Yoke
Assembly out of Housing.
NOTICE
For smaller models (up to 14E3) this can be done by
hand. Larger models may require use of a hoist to
support the weight of the Yoke sub-assembly. For this,
remove the Screw (17) off the Yoke and fit an eye bolt
in place.
9. Secure the Yoke Assembly and remove the Retainer
Plate Screws (28) and the Retainer Plate (24).
Note: For some applications, the Slider Blocks in the Yoke
sub-assembly are replaced by Steel rollers
10. Pull out the Yoke Pin (23), and the upper Slider Block
(22) /Roller(22a), as the case may be.
11. Slide the Guide Block out of the Yoke (21) and remove
the bottom Slider Block/Roller..
12. Remove the Yoke sealing O-rings (5) from the Housing
and Housing Cover, if replacement is required.
13. The Yoke Bushing (4) in the Housing and the Housing
Cover, the Guide Bar Bushing (26) and Yoke Pin Bushing
(27) in the Guide Block are press fitted and may need
suitable workshop tools for removal without damaging
the housing.
6.5.2 Service & Reassembly of the Torque Module
Note: Thoroughly clean/degrease all components prior to
assembly.
1. Replace the bushings in the Housing, the Housing
Cover and the Guide Block with suitable pressing tools.
Contact factory for more information.
2. Secure the Yoke and fit the bottom Retainer Plate
(24) with Screws (28), applying a drop of thread lock
compound on the screw threads.
3. Flip the Yoke over, grease the bottom slot and the Slider
Block (22)/Roller (22a) generously and slide the Slider
Block/Roller into the slot
4. Grease the Guide Block bushings and slide the Guide
Block between the arms of the Yoke aligning the Yoke
Pin bushings with the lower Slider Block/Roller pin hole.
5. Grease the Yoke Pin (23) and slide it through the upper
slot in the Yoke and the Guide Block pin bearings,
locating it in the lower Slider Block/Roller hole. Push the
Yoke Pin down to touch the bottom Retainer Plate.
6. Grease the upper slot and the Slider Block/Roller and
slide it down on the Yoke Pin through the upper slot till
it rests on the Guide Block.
7. Fit the upper Retainer Plate to complete the Yoke
Assembly.
8. Lubricate and Install the Yoke O-ring (5) in the Housing
and grease the bushing and the Yoke seating raised
face.
9. Carefully slide in the Yoke Assembly into the Housing
bushing and push it down to seat it on the raised
seating face in the Housing.
10. Grease and slide in the Guide Bar (2) through the
Housing and Guide Block.
11. If removed previously, screw back the accessory drive
shaft assembly Screw (17) on top of the Yoke, applying
a drop of thread lock compound. Grease the upper
journal of the Yoke.
12. Lubricate and install the Yoke O-ring and Cover O-ring
(6) in the Housing Cover. Ensure the two set screws
on the Housing Cover are fully backed off. Locate the
Housing Cover on the Yoke's upper journal and fit it on
the Housing with the Cover Bolts (12).
13. Locate the Accessory Drive Shaft Assembly on the top

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
© 2020 BRAY INTERNATIONAL, INC. ALL RIGHTS RESERVED. BRAY.COM The Information contained herein shall not be copied, transferred,
conveyed, or displayed in any manner that would violate its proprietary nature without the express written permission of Bray International, Inc. 19 of 84
of the Yoke, locating the plate slot into the screw head.
14. Replace the flanged bushing and the O-rings in the Top
cover and fit it back on the Housing Cover with the Top
Cover Bolts. Fit the indicator on the drive shaft.
15. Apply anti-seize compound on the stopper bolt threads
and thread them with the Lock Nuts into the Torque
Module Housing.
6.6 Reassembly of Actuator
1. Secure the Torque Module on its base.
2. Mark the position and then back off the Travel Stop
Bolts (19) fully and manually turn the Yoke to the side
on which the Pressure Module is to be fixed.
3. Lift the Pressure Module, lubricate and place the module
flange O-ring in the groove. Degrease the Piston Rod
threads, apply a drop of thread lock compound on the
threads and locate the module on the Torque Module’s
mounting flange.
4. Carefully guide the Studs into the flange and center the
module on the spigot (centering ring).
5. Fasten the modules with Spring Washers and Stud Nuts,
refer to the tables for torque values.
6. Take the Plug/End Cover off the End Cap of the Pressure
Module and couple the Piston Rod threads to the Guide
block, using an extended socket or tube spanner for
pneumatic pressure module. Refer to the tables in
Section 10 for torque values. For hydraulic pressure
module, use a hex wrench or a square drive.
7. Install the Plug (or End Cover) with thread sealant and
apply low pressure on the End Cap port till the Yoke
reaches end of stroke. Restrain the Guide Bar from
sliding out of the Housing while stroking.
8. For DA models (refer to Drawing #ES-00020-DA
Assembly), fit the DA End Cover (52) with O-ring (47)
in the groove, using Bolts (51), Nuts (50) and Spring
Washers (49). Skip to step 12.
9. For DD models, pressurize the cap end port of the
mounted cylinder to turn the yoke fully to the other end
to mount the second Pressure Module on the other side
of Torque Module, following relevant actions from steps
3 through 7. Skip to step 12.
10. For Spring Return Models, mount the Spring Module on
the other side of the Torque Module in same manner
as the Pressure Module and couple the Spring Rod
to Guide Block just as was done with the Piston Rod.
Always ensure to tighten the Piston and the Spring Rod
to the recommended torque.
11. Fix the End Cover with O-ring on the Spring Module (or
the Extended Travel Stop/Jackscrew Assembly/Hydraulic
override cylinder, if provided).
12. Set the Travel Stops to previously marked positions.
For spring return actuator, connect air pressure line to
the adaptor port (rod end side port) and slowly raise
pressure enough to start the yoke rotation, to be able to
adjust the spring module side travel stop bolt.
13. Test the actuator for smooth operation at the Maximum
Operating Pressure, as noted on the nameplate.

Series 98 & 98H Scotch Yoke Actuator
Installation, Operation and Maintenance Manual
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7.0 FIELD CONVERSIONS
7.1 Fail Safe Condition (for Spring Return Actuators)
Prior to configuration change, refer to the torque charts and
ensure the actuator's torques would be suitable for the new
application.
The fail safe direction on Series 98 spring return actuator can
be reversed from fail CW to fail CCW and vise versa. This
requires interchanging the position of Pressure and Spring
Modules.
NOTICE
Fail Safe direction change is limited to Symmetric Yoke
actuators. Canted Yoke is meant specifically for FCW
application. It is strongly recommended to take the
actuator off the valve to do the fail safe reversal.
CAUTION
Never try to unscrew and remove the Spring Rod without
completely relieving the spring load on it.
1. Follow the steps for removing the Spring and Pressure
Modules from the actuator, as described in Sections 6.3
and 6.4 respectively.
2. Switch the positions of the two modules, mount the
Pressure Module first. Take care to seat the module
sealing O-ring properly in the groove. Pneumatic
Pressure Module will need to be flipped about its' axis
before mounting if the supply ports are required to be on
the front side of the actuator. On the hydraulic pressure
modules, shift the pipe plugs on ports, as required.
3. Follow instructions in Section 6.6 Reassembly of the
Actuator.
4. Follow Sec. 3.0 to mount the Actuator back on the valve/
gearbox and adjust the travel stop bolts, as required for
proper valve operation. Tighten the Lock Nuts on the
travel Stop Bolts.
5. Check actuator for proper operation, at the rated
working pressure.
NOTICE
Actuator part number and fail direction needs to be
suitably changed on the name plate, after completing
any configuration change. Refer to Technical Manual or
contact factory for information.
7.2 Double Acting to Spring Return
1. To convert the DA actuator to Spring Return (FCW
or FCCW), a Spring Module will need to be mounted
opposite the Pressure Module with a Module Mounting
Kit.
2. If the Pressure Module needs to be shifted, for the
required configuration of the Spring Return actuator,
then first remove the Pressure Module from the actuator.
Follow the procedure in Section 6.4 to remove the
Pressure Module and Section 6.6 for Reassembly of
Actuator. Skip this step if shifting the Pressure Module is
not required.
3. Remove the DA End Cover (52), (refer to Drawing #ES-
00020 – DA Assembly).
4. Tighten the Studs from Module Mounting Kit into the
Spring Module Adaptor, applying thread lock compound
on the threads. Install the module O-ring in adaptor
groove.
5. Follow steps in Section 6.6 for Reassembly of the
Actuator.
6. Set the travel Stop Bolts on the Torque Module as
required for proper valve seating.
7. Remove the air connection from the End Cap port of the
Pneumatic Pressure Module and replace the connector
with a breather-filter. On the hydraulic pressure modules,
connect the cap end port to the hydraulic fluid reservoir.
8. The Spring Return Actuator requires pressure connection
only on the Adaptor port (rod end port.
7.3 Spring Return to Double Acting
1. Remove Spring Module from actuator (refer to Section
6.3).
2. Fit DA End Cover with O-ring and fasteners from the DA
Cover Kit.
3. Adjust travel Stop Bolts, as required.
4. Remove the breather-filter from the End Cap of the
pneumatic Pressure Module and connect suitable
connector for connecting the air line from the direction
control valve.