AERCO ECS Retrofit User Manual

INTERNATIONAL, INC.

159 PARIS AVENUE • NORTHVALE, NJ 07647 • PHONE [phone]

TECHNICAL SERVICE BULLETIN

Date: 04/11/07 REV. Number: 2006-02
Subject: ELECTRONIC CONTROL SYSTEM (ECS) & CONTROL

VALVE, CXT-E RETROFIT INSTRUCTIONS

Page 1 of 81

1. INTRODUCTION

This Service Bulletin provides the procedures necessary to remove an existing Control Valve Actuator
and Control Box and replace it with a new CXT-E Electronic Control Valve Actuator and Electronic
Control System (ECS). These procedures are applicable to all AERCO Indirect-Fired Water Heaters with
Control Valves ranging in size from 1 inch to 4 inches and currently equipped with pneumatic, electro­hydraulic or self-contained valve actuators. In addition, this Service Bulletin applies to both steam-to­water and water-to-water heaters. The types and models covered include:

• HELITHERM HEATER MODELS

• A-Plus

• B-Plus

• B-Plus II (Water Wizard)

• E-Plus

• DOUBLE-WALL HEATER MODELS:

• DW-24

• DW-45

• DW-68

These instructions must be performed by a skilled service technician capable of exercising the necessary
safety precautions when working with high temperature, pressurized steam and water systems.

The following paragraphs in this Section describe the safety precautions to be followed, the tools and test
equipment required to perform all procedures in this Service Bulletin and the contents of the Retrofit Kits
for all Heater Models.

:

1.1 SAFETY PRECAUTIONS

Installation, maintenance and operating personnel must, at all times, observe all safety regulations. The
following warnings are general and must be given the same attention as specific precautions included in
these instructions.

1

FLUIDS UNDER PRESSURE MAY CAUSE INJURY TO
PERSONNEL OR DAMAGE TO EQUIPMENT WHEN RELEASED

Shut off all incoming and outgoing steam and water stop valves and
carefully decrease all trapped pressures to zero before performing any
maintenance.

Never search for leakage in a live steam line by sight alone or by “feel”.
Use a mirror or other suitable polished object.

Always provide yourself with personal protective equipment, (PPE) such as
gloves, eye protection, dust mask, hard hat, etc.

1.2 Tools Required

WARNING!

WARNING!

LIVE STEAM CAN CAUSE SEVERE BURNS

The following tools are required to perform the retrofit procedures specified in this Service Bulletin:

• Combination Wrenches: 7/16”, 9/16”, 5/8”, 13/16”, 1-1/16”, 1-1/8”, 8 mm

• Pipe Wrenches: 12”, 24”

• Vise-Grip Pliers

• Flat Tip Screwdriver, 1/2” Blade

• Phillips Head Screwdriver, No. 3

• Brass Wire Brush

• Needle Nose Pliers

• Tape Measure

• Black Marker

2

1.3 Retrofit Kit Contents

The contents of the Retrofit Kits, Part No. 27004-[ ] are included in Appendices A through D of this
Bulletin. The contents included in these Appendices are as follows:

• Appendix A: Lists the Basic ECS Retrofit Kit contents for each Water Heater Model

• Appendix B: Lists Optional Items based on: valve size, flow rate, type of actuator

currently installed

• Appendix C: Lists Valve Kits required for previously installed Pneumatic and Electro -
Hydraulic Actuators

• Appendix D: Lists Valve Kits required for previously installed Self-Contained
Actuators

WARNING

HIGH VOLTAGE OF 120 VAC IS USED IN AERCO INDIRECT FIRED
WATER HEATERS. USE EXTREME CARE WHEN ACCESSING CIRCUITS
AND ELECTRICAL CONNECTIONS WITHIN THE EQUIPMENT. SERIOUS
PERSONAL INJURY OR DEATH MAY OCCUR IF THIS WARNING IS NOT
OBSERVED. FOLLOW OSHA APPROVED LOCKOUT/TAGOUT
PROCDURES.

2. EQUIPMENT ISOLATION AND REMOVAL PROCEDURES

The locations of the major items to be removed from an AERCO Indirect Fired Water Heater are
shown in Figures 2-1 (Helitherm Models) and 2-2 (Double-Wall Models). These items include:

• Currently Installed Control Valve Actuator (Pneumatic, Self-Contained or Electro-Hydraulic)

• Control Box

• Top Head Solenoid Valve

• Thermal Element

• Shunt Tube

• Temperature Gauges & Capillaries

• Existing Feedback Sensor

• Load Alert Components (Except for Units With Electro-Hydraulic Valves)

In addition to the items listed above, the Drain Ball Valve (if installed) and Cold Water Inlet piping will
be temporarily disconnected to permit installation of a Flow Meter and Orifice Disk.

3

NOTE

Figure 2-1 shows the locations of the affected components and assemblies for
a typical Helitherm, Model SW1B-Plus II Water Wizard installation. Figure 2-2
shows component locations for a typical Double-Wall, Model DW-24.

The actual size and location of affected components and assemblies may
vary, depending on Packaged Water Heater Model, size, and type of Control
Valve being retrofitted. Refer to the applicable AERCO Heat Exchanger
Manual provided with your installation for additional details.

P&T RELIEF VALVE

SECOND OPTIONAL
P&T RELIEF VALVE

SHUNT TUBE

WIRING CONDUIT TO
WATER SOLENOID VALVE

CONTROL BOX

HOT WATER OUTLET

TEMPERATURE GAUGE

COMPOUND

PRESSURE

GAUGE

SHUNT TUBE

COLD WATER IN

DRAIN BALL

VALVE

DRAIN

WATER HEATER

POWER ON TRIPPED

SHELL OUTLET

°F PSIG

STEAM PRESS.

PT.NO.12869­1

CONTROL VALVE*

*NOTE:

HEATER SHOWN WITH
PNEUMATIC CONTROL
VALVE. AN ELECTRO­HYDRAULIC OR SELF­CONTAINED VALVE MAY
ALSO BE USED WITH THE
PACKAGED HEATER.

STEAM
IN

FRONT VIEW

Figure 2-1. Typical Helitherm Water Heater Component Locations (Sheet 1 of 3)

4

Figure 2-1. Typical Helitherm Water Heater Component Locations (Sheet 2 of 3)

5

OUTLET
FLANGE

THERMAL
ELEMENT

P&T RELIEF

VALVE(S)

SHUNT TUBE

MOUNTING

BRACKET

(SAVE)

COLD WATER IN

LOAD ALERT**

CONTROL

BOX

TOP

SOLENOID

VALVE

FEEDBACK
SENSOR

VALVE

**NOTE:

LOAD ALERT NOT
USED WITH ELECTRO­HYDRAULIC CONTROL
VALVE.

SHUNT TUBE

ORIFICE DISC

SPRING RING

DRAIN VALVE

STEAM IN

CONDENSATE OUT

CONTROL
VALVE

BOTTOM

Figure 2-1. Helitherm Water Heater Component Locations (Sheet 3 of 3)

6

SOLENOID
VALVE

S/W

COMPOUND
PRESS. GAGE

TEMP. GAGE

-OR-

W/W

PRIMARY INLET
TEMP. GAGE

MOUNTING

BRACKET

(SAVE)

HOT WATER

OUTLET

CONTROL

BOX

WATER HEATER

POWER ON TRIPPED

TUBE OUTLET

TUBE INLET

°F °F

SHELL OUTLET

°F

VALVE

PT.NO.1
2869-1

PRIMARY OUTLET
TEMP. GAGE

SECONDARY OUT.
TEMP. GAGE

3/4" PLUGGED

DRAIN

CONTROL
VALVE

CONDENSATE/BOILER
WATER OUTLET

STEAM/BOILER
WATER INLET

Figure 2-2. Double-Wall Heater Component Locations (Sheet 1 of 2)

7

RELIEF VALVE

WATER
SOLENOID

CONTROL BOX

DOUBLE WALL
TUBE LEAK

DETECTION PORT

(NOT TO BE
PLUGGED OR
BLOCKED)

COLD WATER
INLET

ORIFICE DISC
& SPRING RING

STEAM/BOILER

WATER INLET

Figure 2-2. Double-Wall Heater Component Locations (Sheet 2 of 2)

NOTE

The majority of illustrations contained in these instructions show a typical
Water Wizard, Model SW1B Plus II Packaged Water Heater. Additional
supporting illustrations are provided only where significant differences exist
between the Water Wizard and the AERCO Heater being retrofitted. For
example: E-Plus Water-to-Water Heaters or Double-Wall (DW) Models.

8

2.1 Isolating Water Heater

To isolate the Water Heater from all facility energy sources (steam, water, electrical power), proceed
as follows:

1. Disconnect and Lock-Out/Tag-Out external AC power supplied to the Control Box and any
other devices connected to the Heater.

2. Using a voltmeter, check to ensure that all incoming voltage readings are zero Before
continuing.

3. If the Heater is equipped with a Pneumatic Control Valve Actuator, close the valve supplying
air inlet pressure to the Pneumatic Controller.

4. Close all stop valves in the Steam Inlet and Condensate Outlet lines. On water-to-water
systems, do not rely on the Boiler Water Out Check Valve to stop the flow of water.

5. On the water-side, close the stop valves in the following order

:

(a) Hot water outlet line

(b) Recirculation line

(c) Cold water inlet line

6. Carefully open the Relief Valve located on the Top Head to relieve pressure in the Heater
Shell. Water should stop flowing from the valve within one minute. If water continues to flow
from the Relief Valve, one of the water stop valves is not securely closed.

2.2 Draining Water Heater

Allow the Water Heater to cool sufficiently prior to draining the unit. When sufficiently cooled, drain as
follows:

1. After ensuring there is no pressure build-up in the Heater Shell (para. 2.1, step 6), block open
the Relief Valve in the Top Head to avoid creating a vacuum in the Heater Shell when it is
drained.

2. Open the Drain Ball Valve in the Bottom Head and allow the potable water in the Heater Shell
to drain completely. If the unit is a Double-Wall Heater (DW-24, DW-45 or DW-68), the Drain is
located on the Shell and may either be plugged with a 3/4” NPT Plug or equipped with a Ball
Valve and additional drain piping. Remove Plug or open Drain Ball Valve as applicable.

9

CAUTION

DO NOT DISCARD ANY OF THE REMOVED PARTS OR ASSEMBLIES
UNLESS IT IS SPECIFICALLY INDICATED THAT THEY WILL NO LONGER
BE USED. IT IS RECOMMENDED THAT ALL REQUIRED ITEMS BE
REMOVED AS INDICATED IN THE FOLLOWING STEPS PRIOR TO
PERFORMING ANY OF THEREPLACEMENT PROCEDURES IN SECTION

3.

2.3 Removal of Components on Top Head Assembly

Virtually all components currently installed in the Water Heater Top Head must be removed prior to
installing the new Electronic Control System and Electronic Valve Actuator. Refer to Figure 2-1, sheet
3 to locate the applicable Top Head components and proceed as follows:

1. Disconnect the pipe drain from the Water Solenoid Relief valve in the Top Head.

2. Disconnect the electrical leads between the Water Solenoid and the Control Box.

3. Remove the 120 VAC Water Solenoid from the nipple connecting it to the Heater Top Head.
This Solenoid will be replaced with a new 24 VDC Solenoid provided in the Retrofit Kit.

4. If a Self-Contained Control Valve is installed with the Heater, remove the Valve’s Temperature
Control Thermal Element from the Thermowell bushing in the Top Head.

5. If a Pneumatic Control Valve is installed with the Heater, remove the Thermal Element and
Bushing.

6. Remove the Dial Thermometer and Thermowell from the Top Head.

7. Remove the Aquastat Capillary and Thermowell from the Top Head.

8. Remove the Anticipator Check Valve (Load Alert) as follows:

(a) Disconnect the union or flange in the hot water outlet piping (located beyond the outside

diameter of the Top Head).

(b) Refer to Figure 2-3. Remove the four hex nuts securing the hot water Outlet Flange to the

Top Head. Remove the Flange, Flange Gasket and outlet piping connected to the Flange.
Retain the four hex nuts for reinstallation of a new Outlet Flange (Section 4).

(c) Remove the Spring Plate Assembly, Spring and Valve Plug Assembly from the Load Alert.

These removed components will no longer be used. Also, the Outlet Flange and Gasket
will be replaced with new components provided in the Retrofit Kit.

10

OUTLET
FLANGE

FLANGE

GASKET

SPRING PLATE

ASSEMBLY

VALVE PLUG

ASSEMBLY

SPRING

HEX NUTS (4)

HOT WATER
OUTLET FLANGE

Figure 2-3. Anticipator Check Valve (Load Alert) Assembly

NOTE

For Double-Wall Heater Models (DW-24, DW-45, DW-68), the items removed
in paragraph 2.4 are located on the Shell of the Heater instead of the Bottom
Head. Therefore, refer to Figure 2-2 for Double-Wall Models.

2.4 Removal of Items Connected to Bottom Head

In order to install several new ECS components, the Drain Ball Valve must be disconnected and the
Cold Water Inlet Orifice Disc replaced. The locations of these items are shown in Figure 2-1, sheet 3.
Proceed as follows:

1. Disconnect any external piping connected to the Cold Water Inlet and Drain Ball Valve Outlet
on the Bottom Head.

2. Locate the Orifice Disc in the Cold Water Inlet (Figure 2-1, sheet 3).

3. Using a pair of pliers, disconnect the snap ring securing the Disc in the Bottom Head.

4. Remove the clip and the Orifice Disc from the Bottom Head. This Orifice Disc will be replaced
in Section 4 with a new Disc provided in the Retrofit Kit.

5. Next, temporarily remove the Drain Ball Valve from the Bottom Head (Figure 2-1, sheet 3).
Retain this Ball Valve for reinstallation in Section 4.

11

2.5 Control Valve Actuator Removal

The Water Heater may currently be equipped with a Pneumatic, Self-Contained or Electro-Hydraulic
Control Valve Actuator. Therefore, refer to the appropriate paragraph for the type of Control Valve
Actuator currently installed.

NOTE

Following removal of the existing Control Valve Actuator, AERCO recom­mends that the Valve Seat and Packing be replaced using the appropriate
items included with the Retrofit Kit. If the Valve is relatively new (less than 1
year) and is currently equipped with a Pneumatic or Electro-Hydraulic
Actuator, replacement of these items may be omitted at the discretion of the
user. However, if the Valve is currently equipped with a Self-Contained
Actuator, replacement of these items is mandatory, since the Valve must be
virtually disassembled to remove the installed Actuator. A new Valve Top (plus
other items) must also be added to Self-Contained Valves before an ECS
Actuator and Linkage Assembly can be installed.

2.5.1 Pneumatic Control Valve Actuator Removal

Refer to Figure 2-4 and remove the Pneumatic Control Valve Actuator as follows:

1. Disconnect the compression fitting connecting the control air line from the Actuator Top.

2. Loosen the hex nut under the indicator disk.

3. Insert a 1/8 inch steel rod in the hole provided in the upper shaft. Hold the rod to keep the
upper shaft from turning when performing the next step.

4. Using a pair of pliers, grasp the lower shaft and rotate it counterclockwise to separate it from
the upper shaft. Use care to avoid scratching the lower shaft.

5. Remove the two 3/8-16 cap screws securing the Pneumatic Actuator to the Valve Body.
Remove the entire Actuator from the Valve.

12

Figure 2-4. Pneumatic Control Valve Actuator Removal

13

2.5.2 Electro-Hydraulic Control Valve Actuator Removal

Refer to Figure 2-5 and remove the Control Valve Actuator as follows:

1. Disconnect the electrical connectors from the Actuator.

2. Loosen the Upper Hex Nut above the Lower Crossbar shown in Figure 2-5.

3. While holding the Lower Shaft with a pair of pliers, completely remove the Upper Hex Nut.

4. Remove the four hex head bolts securing the Electro-Hydraulic Actuator to the Valve Top.

5. Lift the entire Actuator off the Valve Top. Also, remove the Actuator Gasket.

14

Figure 2-5. Electro-Hydraulic Control Valve Actuator Removal

15

2.5.3 Self-Contained Control Valve Actuator Removal

Refer to Figure 2-6 and remove the Self-Contained Valve Actuator as follows:

1. Loosen the locknut on the thermal element adjustment sleeve. Unscrew the adjustment sleeve
to remove the sleeve and thermal element from the Actuator.

2. Carefully loosen the compression fittings on the upstream and downstream tubing to relieve
any trapped pressure buildup. Completely remove both the upstream and downstream tubing
assemblies and compression fittings. The tapped NPT ports in the Valve Body will be plugged
during the replacement procedures in Section 3.

3. Remove the hex head cap screws securing the Actuator to the Valve Body. Valve sizes from
1” to 2” have 6 cap screws, while sizes 2 ½” to 4” Valves have 8 cap screws.

CAUTION

Use care when performing step 4 to avoid damaging or scratching internal
Valve Body parts. It is imperative that the Actuator be lifted straight up to avoid
sticking or binding.

4. Lift the Actuator Housing straight up and off the Valve Body. Doing so will also remove the
entire inner valve assembly (Figure 2-7), including the Valve Stem, Seat, Valve Plug Shaft and
Top/Bottom Pistons. Depending on the age and condition of the valve, considerable force may
be required to pull the Pistons through the Valve Body. If it cannot be removed, the Valve
Stem may be used as an impact hammer to remove scale build-up on the internal valve
surfaces and allow Piston removal.

Replacement parts for these removed items are provided in the applicable Retrofit Kit for the
Valve size being retrofitted. These items will be replaced in Section 3. The Retrofit Kit also
contains a new Lower Shaft, Valve Top/Gasket, plus additional replacement items for the
Valve being retrofitted.

5. Proceed as follows, depending on the size of the Valve being retrofitted:

(a) For 2 ½ to 4 inch Valves, separate the Valve Seat Retaining Disc from the Valve Seat by

removing the four (4) cap screws (Figure 2-7).

(b) For 1 to 2 inch Valves, hold the Valve Plug Shaft with a pair of pliers and remove the

Valve Stem Retaining Nut from the Shaft (Figure 2-8).

6. Insert a 1/8 inch steel rod through the hole near the top of the Valve Stem (Figure 2-7 or 2-8).

NOTE

If “flats” are provided on the Actuator Connecting Shaft and Valve Stem, open­end wrenches may be used in step 7 to disconnect the Valve Stem and
Actuator Shaft.

7. Grasp the Actuator Connecting Shaft (Figure 2-7 or 2-8) with a pair of pliers. Carefully turn the
Valve Stem counterclockwise and separate it from the Actuator Connecting Shaft.

16

8. Replacement of all required Valve parts will be accomplished using the appropriate
instructions and illustrations in Section 3.

THERMAL ELEMENT
ADJUSTMENT SLEEVE

LOCKNUT

1/8" NPT
COMPRESSION
ELBOWS

DOWNSTREAM

TUBE

VALVE

BODY

UPSTREAM
TUBE

HEX HEAD
CAP SCREWS

1/4" NPT
COMPRESSION
ELBOW

Figure 2-6. Self-Contained Control Valve Actuator Removal

17

Figure 2-7. Self-Contained Control Valve Actuator Removal – 2 ½” to 4”

Figure 2-8. Self-Contained Control Valve Actuator Removal – 1” to 2”

18

2.6 Control Box Removal

The existing Control Box (Figure 2-1) is secured to the Heat Exchanger using a special mounting
bracket. The top end of this mounting bracket contains a slotted cutout which is inserted around one
of the studs securing the top head to the shell flange. A hex nut secures the bracket in place. The
currently installed Control Box will no longer be used. However, the mounting bracket will be reused to
mount the new ECS Control Box. Remove the Control Box and mounting bracket assemblies as
follows:

1. Check to ensure that the external power source has been turned off.

2. Disconnect all power supply wiring to the Control Box. Also, disconnect all wiring between the
Control Box and any external Solenoid Valves.

3. If a Pneumatic Control Valve Actuator is currently installed on the Heater, disconnect the air
supply and control air tubing from the Control Box.

4. Disconnect the Pressure Gauge compression fittings.

5. Cut all wire ties leading to the Control Box. Do not cut the thermal element.

6. Loosen, but do not remove, the hex nut securing the Control Box Mounting Bracket to the Top
Head stud (Figure 2-9).

7. Completely remove the Control Box and Mounting Bracket from the Water Heater.

8. Open the Control Box door. From the rear of the Control Box, remove the six 8-32 screws
securing the Rear Mounting Panel to the enclosure (Figure 2-10).

9. Remove the Rear Mounting Panel from the Control Box to access the two screws securing the
Mounting Bracket to the Box

IMPORTANT

Save the Control Box Mounting Bracket when it is removed from the Control
Box. This Mounting Bracket will be used to install the new ECS Control Box.

10. Remove the two screws securing the Mounting Bracket to the Control Box. Separate the
Control Box and Mounting Bracket. This Control Box will no longer be used and can be
discarded. However, the Mounting Bracket will be reused to attach the new ECS Control Box
to the Heater in Section 4.

19

SEE

DETAIL “A”

TOP HEAD

SHELL FLANGE

CONTROL

BOX

MOUNTING

BRACKET

HEX NUT

MOUNTING

BRACKET

(SAVE)

CONTROL

BOX

STUD

TOP HEAD

SHELL FLANGE

HEX NUT

DETAIL “A”

Figure 2-9. Control Box Mounting Details

20

Figure 2-10. Control Box With Door Open

21

3. RECOMMENDED REPLACEMENT OF VALVE ASSEMBLY PARTS

As mentioned in paragraph 2.5, AERCO recommends that the Valve Seat and Packing be replaced
on the Valve Body, prior to installing the ECS Retrofit Kit items described in Section 4. Valve Bodies
which previously utilized Self-Contained Actuators must
such as: a Valve Top, Valve Stem and a Packing Nut.

Refer to the applicable paragraphs which follow for the Valve size and Actuator type used on your
system.

be modified to include new additional items

NOTE

The procedures in paragraphs 3.1 and 3.2 which follow, assume that the
previously installed Pneumatic, Electro-Hydraulic or Self-Contained Actuator
has already been removed.

3.1 Valves Previously Equipped With Pneumatic or Electro-Hydraulic Actuators

The parts replacement items required for Valve Bodies which previously used Pneumatic or Electro­Hydraulic Actuators are basically identical. Only minor variations exist for the various Valve Body
sizes. The Valve Body components for 1.00” to 2.00” and 2.50” to 4.00” are shown in Figures 3-1 and
3-2, respectively.

3.1.1 Valve Disassembly Procedure

Proceed as follows:

NOTE

Steps 1 through 5 which follow apply to all valve sizes shown in Figure 3-1
and 3-2.

1. Remove the Hex Nut (17) from the Valve Body Shaft.

2. Remove the Packing Nut (18) and Packing Assembly (20).

3. Remove the Bolts or Cap Screws (14) securing the Valve Top (21).

4. Remove the Valve Top (21) and Valve Top Gasket (13).

5. Carefully lift out the entire Shaft /Seat/Piston Assembly.

6. For 1 inch to 2 inch Valve sizes, refer to Figure 3-1 and remove the following items in the order
specified:

(a) Lock Washer (23)

(b) Retaining Ring (11)

(c) Pilot Spring (10)

22

(d) Valve Stem Retaining Nut (35)

(e) Lower Shaft (16) and Valve Stem (12)

(f) Retaining Disc (8)

(g) Disc Seat (7)

(h) Seat Retainer (34)

(i) Valve Plug Shaft (5)

7. For 2 ½, 3 and 4 inch Valve sizes, refer to Figure 3-2 and remove the following items in the
order specified:

(a) Lock Washer (23)

(b) Pilot Spring Retainer (11)

(c) Pilot Spring Backup Washer (31), - 4 inch Valve Only

(d) Pilot Spring (10)

(e) Socket Head Cap Screws (9)

(f) Valve Seat Retaining Disc (8)

(g) Lower Shaft (16) and Valve Stem (12)

(h) Valve Seat (7)

(i) Top Piston (6) and Bottom Piston (3) Assemblies

8. Clean all parts thoroughly and remove all dirt and/or scale.

9. Next, proceed to the Valve Reassembly procedures in paragraph 3.1.2 and replace the items
indicated with the new parts provided in the Retrofit Kit.

23

Figure 3-1. Valve Assembly Sizes 1.00” to 2.00”

24

PARTS LIST TABLE FOR VALVE ASSEMBLY SIZES 1.00” TO 2.00”

VALVE SIZE AND PART NUMBERS

ITEM QTY PART NAME 1.00 INCH 1.25 INCH 1.50 INCH 2.00 INCH

1 1 VALVE BODY 20762 20759 20758 20761

2 1 SEAT CAGE 16844 16845 16837 16843

3 1 BOTTOM PISTON 121540 121525 121502 121529

4 NOT USED

5 1 VALVE PLUG SHAFT 16849 16839 16838 16848

6 1 TOP PISTON 121539 12154 121501 121530

7 1 DISC SEAT 121541 121527 121510 121531

8 1 RETAINING DISC 121542 121513 121504 121532

9 NOT USED

10 PILOT SPRING 121528 121528 121528 121528

11 1 RETAINING RING 121545 121545 121545 121545

12 1 VALVE STEM 122655 122654 122651 122650

13 1 VALVE TOP GASKET 122136 122136 122136 122136

14 6 BOLT, HEX, 3/8-16 122405 122405 122405 122405

16 1 LOWER SHAFT 121979 121980 121980 121982

17 2 HEX NUT, 1/4-20 6-226 6-226 6-226 6-226

18 1 PACKING NUT 122664 122664 122664 122664

19 2 BOLT, HEX 3/8-16 x 5/8 LG 54014 54014 54014 54014

20 1 PACKING ASSY 121567 121567 121567 121567

21 1 VALVE TOP 16943 16943 16943 16943

22 NOT USED

23 1 LOCKWASHER 122666 122666 122666 122666

24 1 SEAT CAGE GASKET 123080 123081 123082 123083

ITEMS

25

THRU

30

31 1

32 1 TOP PISTON RETAINING NUT 121543 121543 121543 121543

33 1 LOWER PILOT SEAT ASSY 121505 121505 121505 121505

NOT SHOWN

BOTTOM PISTON RETAINING NUT

122982 122982 122982 122982

34 1 SEAT RETAINER N/A 121559 121506 121506

35 1 VALVE STEM RETAINING NUT 121503 121503 121503 121503

25