Emerson Fisher YD User manual

www.Fisher.com
Fisher™YD and YS 3‐Way Valves
Contents
Introduction 1.................................
Scope of Manual 1.............................
Specifications 2...............................
Educational Services 2.........................
Installation 3..................................
Maintenance 4.................................
Packing Lubrication 5..........................
Packing Maintenance 6.........................
Packing Replacement 6.....................
Trim Maintenance 7...........................
Disassembly 7.............................
Assembly 12..............................
ENVIRO‐SEALtBellows Seal Bonnet 16...........
Replacing a Plain or Extension Bonnet with an
ENVIRO‐SEAL Bellows Seal Bonnet
(Stem/Bellows Assembly) 16..............
Replacement of an Installed
ENVIRO‐SEAL Bellows Seal Bonnet
(Stem/Bellows Assembly) 18..............
Purging the ENVIRO‐SEAL
Bellows Seal Bonnet 19...................
Parts Ordering 24...............................
Parts Kits 24...................................
Gasket Kits 25.................................
Parts List 26...................................
YD and YS Valve 26............................
Bonnet for YD and YS 26........................
Figure 1. Fisher YD Valve with 667 Actuator
W2081
Introduction
Scope of Manual
This instruction manual includes installation, maintenance, and parts information for NPS 1/2 through 8 YD and NPS
1/2 through 6 YS control valves. Refer to separate manuals for instructions covering the actuators and accessories.
Do not install, operate, or maintain YD or YS valves without being fully trained and qualified in valve, actuator, and
accessory installation, operation, and maintenance. To avoid personal injury or property damage, it is important to
carefully read, understand, and follow all the contents of this manual, including all safety cautions and warnings. If you
have any questions about these instructions, contact your Emerson sales office or Local Business Partner before
proceeding.
Instruction Manual
D100425X012
YD and YS Valves
July 2017

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Table 1. Specifications
Valve Sizes, Ratings, and End Connections (1,2)
Cast Iron Valves
Flanged: NPS 1‐1/2 through 6 CL125 flat‐face or
CL250 raised‐face flanges per ASME B16.1
Screwed: NPS 1‐1/2 and 2 consistent with ASME B16.4
Steel and Stainless Steel Valves
Flanged: NPS 1 through 8 CL150, 300, and 600
raised‐face or ring‐type joint flanges per ASME B16.5
Screwed or Socket Welding: NPS 1/2 through 2
consistent with ASME B16.11
Buttwelding: NPS 1 through 8. All available
ASME B16.25 schedules that are consistent with
ASME B16.34
Also see table 2
Maximum Inlet Pressure(1)
Cast Iron Valves
Flanged: Consistent with CL125B or 250B per ASME
B16.1
Screwed: Consistent with CL250 per ASME B16.4
WCC and Stainless Steel Valves
Flanged: Consistent with CL150, 300, and 600(3) per
ASME B16.34
Screwed or Welding: Consistent with flanged CL600
per ASME B16.34
Do not exceed the pressure, temperature, and
pressure drop conditions specified when the valve
was ordered. See the Installation section for
additional information.
Shutoff Classifications per ANSI/FCI 70‐2
and IEC 60534‐4
YD
Standard Design: Class IV
High‐Temperature Design: Class II
YS
Standard Class: Class IV
Optional Class: Class V
Flow Characteristic
Linear
Approximate Shipping Weights
NPS 1/2, 3/4 Valves: 14 kg (30 pounds)
NPS 1 Valves: 18 kg (40 pounds)
NPS 1‐1/2 Valves: 27 kg (60 pounds)
NPS 2 Valves: 39 kg (85 pounds)
NPS 2‐1/2 Valves: 50 kg (110 pounds)
NPS 3 Valves: 68 kg (150 pounds)
NPS 4 Valves: 109 kg (240 pounds)
NPS 6 Valves: 227 kg (500 pounds)
NPS 8 Valves: 447 kg (985 pounds)
1. EN (or other) ratings and end connections can usually be supplied; consult your Emerson sales office or Local Business Partner.
2. The pressure or temperature limits in this manual, and any applicable standard limitations, should not be exceeded.
3. Certain bonnet bolting material selections may require a CL600 easy‐e valve assembly to be derated. Contact your Emerson sales office or Local Business Partner.
Description
The YD and YS valves are three‐way valves for throttling or on‐off (flow switching) service with converging (flow
mixing) or diverging (flow splitting) flow patterns. YS valves, when used in diverging service, are recommended for
on‐off applications only. These valves are generally shipped as part of a control valve assembly, having a diaphragm,
piston, or manual actuator mounted on them. A typical construction is shown in figure 1.
Specifications
Specifications for the YD and YS valves are shown in table 1. Some specifications appear on the actuator nameplate if
the valve is part of a complete control valve assembly.
Educational Services
For information on available courses for Fisher YD and YS valves, as well as a variety of other products, contact:
Emerson Automation Solutions
Educational Services - Registration
Phone: [phone] or 1-800-338-8158
E-mail: [email protected]
emerson.com/fishervalvetraining

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Installation
WARNING
Always wear protective gloves, clothing, and eyewear when performing any maintenance operations to avoid personal
injury.
Personal injury or equipment damage caused by sudden release of pressure might result if the valve assembly is installed
where service conditions could exceed the limits given in table 1 or on the appropriate nameplates. To avoid such injury or
damage, provide a relief valve for overpressure protection as required by government or accepted industry codes and good
engineering practices.
Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
If installing into an existing application, also refer to the WARNING at the beginning of the Maintenance section in this
instruction manual.
CAUTION
When ordered, the valve configuration and construction materials were selected to meet particular pressure, temperature,
pressure drop, and controlled fluid conditions. Responsibility for the safety of process media and compatibility of valve
materials with process media rests solely with the purchaser and end‐user. Since some body/trim material combinations
are limited in their pressure drop and temperature ranges, do not apply any other conditions to the valve without first
contacting your Emerson sales office or Local Business Partner.
Before installing the valve, inspect the valve and pipelines for any damage and any foreign material which may cause
product damage.
1. Before installing the valve, inspect it for any shipping damage and for any foreign material in the valve body cavity.
2. Clean out all pipelines to remove pipe scale, chips, welding slag, and other foreign materials.
3. Use accepted piping and welding practices when installing the valve. For flanged valves, use suitable gaskets
between the valve and the pipeline flanges.
4. Do not install the valve in a system where the working pressures exceed those specified in the ASME
pressure/temperature ratings or those specified by Emerson Automation Solutions.
5. If continuous operation is required during maintenance and inspection, install a conventional three‐valve bypass
around the valve so that the valve can be isolated.
6. Orient the valve so that flow will be in the direction indicated by the flow arrows.
Note
The common port for the YD is the bottom port as shown on the flow direction plates (key 17) in figure 10. The common port for
the YS is the left‐hand port as shown on the flow direction plates in figure 9.
CAUTION
Depending on valve body materials used, post weld heat treating may be required. If so, damage to internal elastomeric
and plastic parts, as well as internal metal parts is possible. Threaded connections may also loosen. In general, if post weld

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heat treating is to be performed, all trim parts should be removed. Contact your Emerson sales office or Local Business
Partner for additional information.
7. YD or YS control valves can be installed in any position, although the recommended position is with the actuator
vertical above the valve. For NPS 4 and 6 YS valves, size 80 or larger actuators mounted between 45 degrees above
and 45 degrees below horizontal should be supported. If forces other than normal gravitational forces are
experienced, such as vibrational forces, smaller size actuators might also need to be supported when they are not in
a vertical position. For further information, consult your Emerson sales office or Local Business Partner.
Table 2. Valve Body Sizes and End Connections
VALVES SIZE, NPS CAST IRON VALVES STEEL OR STAINLESS STEEL VALVES
1/2, 3/4 ‐ ‐ ‐ NPT screwed or socket weld
1‐ ‐ ‐ NPT screwed; CL150, 300, or 600 raised‐face or ring‐type
joint flanged; buttwelding; or socket weld
1‐1/2, 2 NPT screwed; CL125 flat‐face flanged; or CL250 raised‐face flanged NPT screwed; CL150, 300, or 600 raised‐face or ring‐type
joint flanged; buttwelding; or socket weld
2‐1/2, 3, 4, 6 CL125 flat‐face or CL250 raised‐face flanged CL150, 300, or 600 raised face or ring‐type joint flanged;
or buttwelding
8‐ ‐ ‐ CL150, 300, or 600 raised face, ring-type joint, or
buttwelding
WARNING
Personal injury could result from packing leakage. Valve packing was tightened before shipment; however, the packing
might require some readjustment to meet specific service conditions. Check with your process or safety engineer for any
additional measures that must be taken to protect against process media.
Valves with ENVIRO‐SEAL live‐loaded packing or HIGH‐SEAL live‐loaded packing will not require this initial
re‐adjustment. See the Fisher instruction manuals titled ENVIRO‐SEAL Packing System for Sliding‐Stem Valves or
HIGH‐SEAL Live‐Loaded Packing System (as appropriate) for packing instructions. If you wish to convert your present
packing arrangement to ENVIRO‐SEAL packing, refer to the retrofit kits listed in the parts kit subsection near the end of
this manual.
Maintenance
Valve parts are subject to normal wear and must be inspected and replaced as necessary. Inspection and maintenance
frequency depends on the severity of service conditions. This section includes instructions for trim maintenance,
packing maintenance, and ENVIRO‐SEAL bellows seal bonnet replacement. All maintenance operations may be
performed with the valve in the line.
WARNING
Avoid personal injury or property damage from sudden release of process pressure or uncontrolled movement of parts.
Before performing any maintenance operations:
D Do not remove the actuator from the valve while the valve is still pressurized.
D Always wear protective gloves, clothing, and eyewear when performing any maintenance operations to avoid personal
injury.
D Disconnect any operating lines providing air pressure, electric power, or a control signal to the actuator. Be sure the
actuator cannot suddenly open or close the valve.

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D Use bypass valves or completely shut off the process to isolate the valve from process pressure. Relieve process pressure
from both sides of the valve. Drain the process media from both sides of the valve.
D Vent the power actuator loading pressure and relieve any actuator spring precompression.
D Use lock‐out procedures to be sure that the above measures stay in effect while you work on the equipment.
D The valve packing box may contain process fluids that are pressurized, even when the valve has been removed from the
pipeline. Process fluids may spray out under pressure when removing the packing hardware or packing rings, or when
loosening the packing box pipe plug.
D Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
CAUTION
Follow instructions carefully to avoid damaging the product surfaces, which could result in damage to the product.
Packing Lubrication
Figure 2. Lubricator and Lubricator/Isolating Valve (Optional)
LUBRICATOR LUBRICATOR/ISOLATING VALVE
10A9421‐A
AJ5428‐D
A0832‐2
Note
ENVIRO‐SEAL and HIGH‐SEAL packing do not require lubrication.
WARNING
To avoid personal injury or property damage resulting from fire or explosion, do not lubricate packing used in oxygen
service or in processes with temperatures over 260_C (500_F).
If a lubricator or lubricator/isolating valve (figure 2) is provided for PTFE/composition or other packings that require
lubrication, it will be installed in place of the pipe plug (key 14, figure 13). Use a good quality silicon‐base lubricant. Do
not lubricate packing used in oxygen service or in processes with temperatures over 260_C (500_F). To operate the
lubricator, simply turn the cap screw clockwise to force the lubricant into the packing box. The lubricator/isolating
valve operates the same way except open the isolating valve before turning the cap screw and then close the isolating
valve after lubrication is completed.

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Packing Maintenance
Note
For valves with ENVIRO‐SEAL packing, see the Fisher instruction manual ENVIRO‐SEAL Packing System for Sliding‐Stem Valves for
packing instructions.
For valves with HIGH‐SEAL packing, see the Fisher instruction manual HIGH‐SEAL Live‐Loaded Packing System for packing
instructions.
Packing Replacement
WARNING
Observe the warning at the start of the Maintenance section.
Table 3. Recommended Torque for Packing Flange Nuts
VALVE STEM
DIAMETER PRESSURE
RATING
GRAPHITE TYPE PACKING PTFE TYPE PACKING
Minimum Torque Maximum Torque Minimum Torque Maximum Torque
mm Inches NSm LbfSin NSm LbfSin NSm LbfSin NSm LbfSin
9.5 3/8
CL125,
150 3 27 5 40 1 13 2 19
CL250,
300 4 36 6 53 2 17 3 26
CL600 6 49 8 73 3 23 4 35
12.7 1/2
CL125,
150 5 44 8 66 2 21 4 31
CL250,
300 7 59 10 88 3 28 5 42
CL600 9 81 14 122 4 39 7 58
19.1 3/4
CL125,
150 11 99 17 149 5 47 8 70
CL250,
300 15 133 23 199 7 64 11 95
CL600 21 182 31 274 10 87 15 131
25.4 1 CL300 26 226 38 339 12 108 18 162
CL600 35 310 53 466 17 149 25 223
31.8 1‐1/4 CL300 36 318 54 477 17 152 26 228
CL600 49 437 74 655 24 209 36 314
The following procedure covers PTFE V‐ring packing. A similar procedure can be followed for PTFE/composition
packing. However, because PTFE/composition packing comes in split rings, it is possible to replace the rings without
removing the actuator from the valve.
Installation of graphite ribbon/filament packing requires special care to avoid trapping air between the rings. Start only
one ring at a time without forcing the top of the packing ring below the bottom of the entrance chamfer of the
packing box. Thus, when a ring is added, the stack should not be pushed into the cavity more than the thickness of the
added ring.
The arrangement of packing box parts is shown in figures 3, 4, 5, 6, and 7. Key numbers used in the following steps are
shown in figures 13 and 14.

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1. Remove the actuator and bonnet according to steps 1 through 4 of the Disassembly procedure in the Maintenance
section on page 7.
2. With the stem and valve plug assembly removed from the bonnet, remove the packing nuts (key 5), packing flange
(key 3), wiper ring (key 12), and packing follower (key 13) from the bonnet. The old packing can then be pulled out
with a packing hook (take care to avoid scratching the packing box wall) or pushed out using a rod inserted through
the bottom of the bonnet.
3. Clean the packing box and all metal parts.
4. Complete maintenance necessary on other parts and install the bonnet on the valve as indicated in the Assembly
section (starting on page 12).
5. Install the new packing and associated parts in the sequence shown in figures 3, 4, 5, 6, and 7. Be careful not to
damage the packing during installation.
6. Replace the packing flange and packing flange nuts.
For spring‐loaded PTFE V‐ring packing, tighten the packing flange nuts until the shoulder on the packing follower
contacts the bonnet.
For graphite packing, tighten the packing flange nuts to the maximum recommended torque shown in table 3. Then,
loosen the packing flange nuts, and retighten them to the recommended minimum torque shown in table 3.
For other packing types, tighten the packing flange nuts alternately in small equal increments until one of the nuts
reaches the minimum recommended torque shown in table 3. Then, tighten the remaining flange nut until the
packing flange is level and at a 90‐degree angle to the valve stem.
For ENVIRO‐SEAL or HIGH‐SEAL live‐loaded packing, refer to the note at the beginning of the Packing Maintenance
section.
7. Mount the actuator on the bonnet and make up the stem connection according to the procedure given in the
appropriate actuator instruction manual.
Trim Maintenance
WARNING
Observe the warning at the start of the Maintenance section.
CAUTION
To avoid damaging parts, do not grip the bellows shroud or other parts of the stem/bellows assembly. Grip only the flat
areas on the stem where it extends out of the top of the bellows shroud.
Key numbers in the following procedures are shown in figure 10 for standard YD, in figure 11 for high‐temperature YD,
and in figure 9 for YS, except where indicated.
Disassembly
1. Isolate the control valve from the line pressure, release pressure from both sides of the valve, and drain the process
media from both sides of the valve. Remove actuator supply pressure, and use lock‐out procedures to be sure that
the above measures stay in effect while you work on the equipment.

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YD and YS Valves
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WARNING
See the WARNING at the beginning of the Maintenance section for more information.
2. Disconnect the actuator stem connector and remove the locknut (key 15, figure 13) that holds the actuator to the
valve. (Valves with a 127 mm (5‐inch) yoke boss use cap screws and nuts to secure the actuator on the valve). Then
lift the actuator from the valve.
Figure 3. Fisher PTFE V‐Ring Packing Arrangements
UPPER WIPER
(KEY 12)
PACKING
FOLLOWER (KEY 13)
LANTERN RING
(KEY 8)
PACKING BOX
RING (KEY 11)
MALE ADAPTOR
PACKING RING
FEMALE ADAPTOR
LOWER WIPER
ASSEMBLY 1
(POSITIVE
PRESSURES)
ASSEMBLY 2
(VACUUM) ASSEMBLY 3 (POSITIVE
PRESSURES
& VACUUM)
ASSEMBLY 1
(POSITIVE
PRESSURES)
ASSEMBLY 2
(VACUUM) ASSEMBLY 3 (POSITIVE
PRESSURES
& VACUUM)
ASSEMBLY 1
(POSITIVE
PRESSURES)
ASSEMBLY 2
(VACUUM) ASSEMBLY 3 (POSITIVE
PRESSURES
& VACUUM)
9.5 mm (3/8 INCH) STEM 12.7 mm (1/2 INCH) STEM 19.1, 25.4, OR 31.8 mm
(3/4, 1, OR 1‐1/4 INCH) STEM
DOUBLE ARRANGEMENTS
12A8187-C 12A7814-C 12A7839-A
B1428‐2
UPPER WIPER
(KEY 12)
PACKING
FOLLOWER (KEY 13)
PACKING BOX
RING (KEY 11)
FOR 316 OR 17‐4PH SST
METAL PACKING BOX PARTS
SINGLE ARRANGEMENT
12A7837-A
B1429-2
FOR ALL OTHER METAL PACKING
BOX PART MATERIALS
SPACER (KEY 8)
UPPER WIPER
(KEY 12)
PACKING
FOLLOWER
(KEY 13)
PACKING BOX
RING (KEY 11)
FEMALE
ADAPTOR
FEMALE
ADAPTOR
MALE
ADAPTOR
PACKING
RING MALE
ADAPTOR
PACKING
RING
WASHER
(KEY 10)
SPRING
(KEY 8)
PACKING
SET
(KEY 6)
LOWER
WIPER
LOWER
WIPER

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YD and YS Valves
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Figure 4. Detail of Fisher PTFE/Composition Packing Arrangements
UPPER WIPER
(KEY 12)
PACKING
FOLLOWER (KEY 13)
LANTERN RING
(KEY 8)
PACKING BOX
RING (KEY 11)
PACKING RING
(KEY 7)
9.5 mm
(3/8 INCH)
STEM
12.7 mm
(1/2 INCH)
STEM
19.1, 25.4, OR 31.8 mm
(3/4, 1, OR 1‐1/4 INCH)
STEM
TYPICAL (DOUBLE) ARRANGEMENTS
12A8188‐A
12A7815‐A
12A8173‐A
A2619‐1
Figure 5. Fisher Graphite Ribbon/Filament Packing Arrangements
PACKING
FOLLOWER
PACKING BOX
RING
1
GRAPHITE
RIBBON
PACKING RING
GRAPHITE
FILAMENT
PACKING RING
14A1780-B
14A1849-B
14A2153-B
12.7 mm
(1/2‐INCH)
STEM
9.5 mm
(3/8‐INCH)
STEM
19.1 OR 25.4 mm
(3/4 OR 1‐INCH)
STEM
1
1
1
1
1
NOTE:
0.102 mm (0.004 INCH) THICK SACRIFICIAL ZINC WASHERS.
USE ONLY ONE BELOW EACH GRAPHITE RIBBON RING.
HAS THE APPEARANCE OF A WOVEN OR BRAIDED RING.
A2438‐2
1
2
LANTERN RING
2
PACKING
FOLLOWER
PACKING BOX
RING
GRAPHITE
RIBBON
PACKING RING
GRAPHITE
FILAMENT
PACKING RING
2
1
1
1
13A9776-B
13A9775-B
14A3411-A
12.7 mm
(1/2‐INCH)
STEM
9.5 mm
(3/8‐INCH)
STEM
19.1 OR 25.4 mm
(3/4 OR 1‐INCH)
STEM
SINGLE PACKING ARRANGEMENT DOUBLE PACKING ARRANGEMENT
LANTERN RING

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Figure 6. PTFE Packing Arrangements for Use in Fisher ENVIRO‐SEAL Bellows Seal Bonnets
UPPER WIPER
(KEY 12)
PACKING SET: (KEY 6)
FEMALE ADAPTOR
PACKING RING
MALE ADAPTOR
BUSHING (KEY 13)
9.5 mm
(3/8 INCH)
STEM
12.7 mm
(1/2 INCH)
STEM
DOUBLE ARRANGEMENTS
9.5 mm
(3/8 INCH)
STEM
9.5 mm
(3/8 INCH)
STEM
12.7 mm
(1/2 INCH)
STEM FOR
NPS 2 VALVES
12.7 mm
(1/2 INCH)
STEM FOR
NPS 3 AND 4 VALVES
THRUST
RING
(KEY 39)
SPRING
(KEY 8)
THRUST
RING
(KEY 39)
THRUST
RING
(KEY 39)
BUSHING
(KEY 13)
BUSHING
(KEY 13)
SPACER
(KEY 8)
SPACER
(KEY 8)
SPACER
(KEY 8)
12.7 mm
(1/2 INCH)
STEM
SINGLE ARRANGEMENTS
FOR S31600 (316 SST)
PACKING BOX PARTS
FOR ALL PACKING BOX
MATERIALS EXCEPT S31600
UPPER WIPER
(KEY 12)
PACKING SET: (KEY 6)
FEMALE ADAPTOR
PACKING RING
MALE ADAPTOR
BUSHING (KEY 13)
SPACER
(KEY 8)
A5863
12B4183-A 18A0906-D 18A5338-A
12B4182-A SHT 1 12B4185-A SHT 1 12B4182-A SHT 2 12B4185-A SHT 2
3. Remove the nuts (key 16, figures 9 and 10) or cap screws from the bonnet flange.
4. Lift off the bonnet along with the valve plug and stem (keys 2 and 5, figures 9 and 10). Due to the design of the
valve, several other trim parts will be drawn out with the valve plug. They are as follows:
YD (Standard)‐‐The upper cage (key 3A) and associated seals, gaskets, and shim (keys 9, 11, 19, 20A, 20B, and 22).
YD (High Temperature)‐‐The upper cage (key 3B) and associated gaskets and shim (keys 9, 11, and 22).
YS‐‐The upper seat (key 7), upper cage (key 3), and associated gaskets and shim (keys 9, 11, and 22).
CAUTION
The exposed portion of the cage provides a guiding surface that must not be damaged during disassembly or maintenance.
Damage could affect valve performance. If the cage is stuck in the valve, use a rubber mallet to strike the exposed portion
at several points around the circumference.

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Figure 7. Double Graphite Ribbon/Filament Arrangements for Use in Fisher ENVIRO‐SEAL Bellows Seal Bonnets
BUSHING (KEY 13)
SPACER (KEY 8)
1
GRAPHITE FILAMENT PACKING RING (KEY 7)
GRAPHITE RIBBON PACKING RING (KEY 7)
12B6102‐A
18A0909‐D
12B4181‐A
12.7 mm
(1/2‐INCH)
STEM FOR
NPS 2 VALVES
9.5 mm
(3/8‐INCH)
STEM
12.7 mm
(1/2‐INCH)
STEM FOR
NPS 3 AND 4 VALVES
1
1
1
1
1
NOTE:
0.102 mm (0.004 INCH) THICK SACRIFICIAL ZINC WASHERS;
USE ONLY ONE BELOW EACH GRAPHITE RIBBON RING.
A5870
1
Take proper care not to damage any sealing or seating surfaces as nicks or scratches in these parts might cause
leakage.
5. Loosen the packing flange nuts (key 5, figures 13 and 14) and draw the valve plug and stem straight out the bottom
of the bonnet. Lift all cage and seat parts off the valve plug and stem. If the stem for YD or YS requires replacing,
drive the pin (key 6) out and unscrew the stem from the plug.
Table 4. Pin Drill Sizes
VALVE TYPE VALVE STEM CONNECTION, mm (INCH) DRILL SIZE, INCHES
YD & YS
9.5 (3/8)
12.7 (1/2)
3/32
1/8
19.1 (3/4)
25.4 (1)
3/16
1/4
Table 5. Recommended Bolt Torques for B7 Body‐to‐Bonnet Bolting(1)
VALVE SIZE,
NPS
RECOMMENDED BOLT
TORQUE, NSm (LbfSft)
1/2, 3/4
1, 1‐1/2
129 (95)
129 (95)
2
2‐1/2
96 (71)
96 (71)
3
4
6
169 (125)
271 (200)
549 (405)
8(2) CL150/300: 373 (275)
CL600: 522 (385)
1. For other materials, contact your Emerson sales office or Local Business Partner.
2. For NPS 8 YD valves, the bottom adaptor has shorter bolts than the bonnet, but the bolt torque is the same as the bonnet torque.
6. To replace the adaptor (key 24, figure 15) on ENVIRO‐SEAL bellows seal bonnets, place the plug stem assembly and
valve plug in a soft‐jaw chuck or other type of vise so that the jaws grip a portion of the valve plug that is not a
seating surface. Drive out the pin (key 36, figure 15). Reverse the plug stem assembly in the soft‐jaw chuck or vise.
Grip the flat areas on the valve stem just below the threads for the actuator/stem connection. Unscrew the valve
plug/adaptor assembly (key 24, figure 15) from the valve stem assembly (key 20, figure 15).

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CAUTION
Never use an old stem with a new valve plug. The use of an old stem requires drilling a new pin hole through the stem (or
adaptor, in case an ENVIRO‐SEAL bellows seal bonnet is being used). This drilling weakens the stem or adaptor and may
cause failure in service. However, a used valve plug may be reused with a new stem or adaptor.
7. The internal parts of the bonnet can now be disassembled, if necessary. For packing replacement, refer to the
section entitled Packing Replacement on page 6.
8. Standard YD Only—It is recommended that the cage seal (key 19), seal ring (key 20A), and backup ring (key 20B) be
replaced upon assembly. These can be removed by prying them out of the upper cage grooves with a screwdriver or
a soft‐tipped instrument. If a screwdriver is used, take care not to scratch the surfaces of the cage.
9. The remaining trim parts can now be lifted out of the valve. Under severe service conditions, some of these parts
might have become stuck to the valve. In this case, it might be necessary to use a seat ring puller to remove these
parts. Because there is a slight clearance around the outer circumference of the lower cage (key 4) and seat ring
(key 8), it might be possible to remove these by tapping them loose, if interior room permits.
Assembly
YD (Standard)
1. Use new gaskets, seals, and shim (keys 9, 11, 14, 19, 20A, 20B, and 22) on assembly and wipe all sealing surfaces
with a clean cloth.
2. For NPS 8 YD, install the bottom flange adaptor (key 24) and gasket (key 9).
3. Install the seat ring gasket (key 14) and place the seat ring (key 8) on top of the gasket.
4. Install the lower cage (key 4) into the valve, being certain that it fits down over the raised portion of the seat ring.
The narrow portion of the cage windows should point downward.
5. Slip the O‐ring cage seal (key 19) over the bottom of the upper cage (key 3A) and into the cage groove.
Figure 8. Typical Bolting Pattern
A0274‐1
6. Press the backup ring (key 20B) and the seal ring (key 20A), respectively, into the inner groove of the upper cage. It
might be necessary to bend one side of each of these in slightly to accomplish this. Take care not to distort the rings
when doing this.
7. If a new stem (key 5) is to be used, screw the stem into the valve plug (key 2) until it wedges tight at the end of the
valve stem thread.

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CAUTION
Never use an old stem with a new valve plug. The use of an old stem requires drilling a new pin hole through the stem (or
adaptor, in case an ENVIRO‐SEAL bellows seal bonnet is being used). This drilling weakens the stem or adaptor and may
cause failure in service. However, a used valve plug may be reused with a new stem or adaptor.
Locate the pilot hole in the valve plug and drill the hole through the plug and stem assembly (determine drill size from
table 4). Drive in the pin to lock the assembly.
8. For ENVIRO‐SEAL bellows seal bonnets, grip the flats of the stem extending out of the top of the bellows shroud
with a soft‐jaw chuck or other type of vise. Screw the valve plug/adaptor assembly onto the valve stem. Tighten as
necessary to align the pin hole in the stem with one of the holes in the adaptor. Secure the adaptor to the stem with
a new pin.
CAUTION
To prevent possible damage to the seal ring and cage seal, exercise care in the following procedure.
9. Place the upper cage (key 3A) over the plug assembly, being certain not to damage the seal ring, and lower this
entire assembly into the valve. Due to the close fit between the valve body bore and the cage seal, it will be
necessary to apply a steady force to the top of the cage for final positioning inside the valve body bore. Take care to
ensure that the upper cage slips into the lower cage and the cage seal is not damaged.
10. Place the spiral wound gasket (key 11), shim (key 22), and bonnet gasket (key 9), respectively, over the upper
cage.
11. Mount the bonnet onto the valve with the lubricator or pipe plug parallel with the pipeline.
Note
Stud(s) and nut(s) should be installed such that the manufacturer's trademark and material grade marking is visible, allowing easy
comparison to the materials selected and documented in the Emerson/Fisher serial card provided with this product.
WARNING
Personal injury or damage to equipment could occur if improper stud and nut materials or parts are used. Do not operate or
assemble this product with stud(s) and nut(s) that are not approved by Emerson/Fisher engineering and/or listed on the
serial card provided with this product. Use of unapproved materials and parts could lead to stresses exceeding the design
or code limits intended for this particular service. Install studs with the material grade and manufacturer's identification
mark visible. Contact your Emerson Automation Solutions representative immediately if a discrepancy between actual
parts and approved parts is suspected.

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12. Lubricate the valve stud bolts or cap screws (key 15) and install the nuts (key 16) on the bolts using accepted
bolting practices. Tighten the nuts to the recommended bolt torques given in table 5. Follow a pattern similar to
that shown in figure 8.
Note
It might be necessary to repeat the bolting pattern several times until the bonnet‐to‐body seal is made, because the tightening of
one nut might loosen an adjacent nut. Repeat the pattern until none of the nuts will turn at the recommended torque.
13. Mount the actuator on the bonnet and make up the stem connection according to the procedure given in the
appropriate actuator instruction manual.
YD (High Temperature)
1. Use new gaskets, seals, and shim (keys 9, 11, 13, 14, 19, 20, and 22) on assembly and wipe all sealing surfaces with
a clean cloth.
2. For NPS 8 YD, install the bottom flange adaptor (key 24) and gasket (key 9).
3. Install the seat ring gasket (key 14) and place the seat ring (key 8) on top of the gasket followed by the spiral wound
spring (key 13).
4. Install the lower cage (key 4) into the valve, being certain that it fits down over the raised portion of the seat ring.
The narrow portion of the cage windows should point downward.
5. Place one of the retaining ring gaskets (key 19) into the valve.
6. If a new stem (key 5) is to be used, screw the stem into the valve plug (key 2) until it wedges tight at the end of the
valve stem thread.
CAUTION
Never use an old stem with a new valve plug. The use of an old stem requires drilling a new pin hole through the stem (or
adaptor, in case an ENVIRO‐SEAL bellows seal bonnet is being used). This drilling weakens the stem or adaptor and may
cause failure in service. However, a used valve plug may be reused with a new stem or adaptor.
Locate the pilot hole in the valve plug and drill the hole through the plug and stem assembly (determine drill size from
table 4). Drive in the pin to lock the assembly.
7. For ENVIRO‐SEAL bellows seal bonnets, grip the flats of the stem extending out of the top of the bellows shroud
with a soft‐jaw chuck or other type of vise. Screw the valve plug/adaptor assembly onto the valve stem. Tighten as
necessary to align the pin hole in the stem with one of the holes in the adaptor. Secure the adaptor to the stem with
a new pin.
8. Place the seal ring retainer (key 3C) into the valve and lower the valve plug assembly into the retainer orifice.
9. Carefully place the seal rings (key 20) over the valve plug, being certain that they rest against the retaining ring.
Each of these has a cut through its cross section. These cuts should be oriented 180 degrees apart to ensure a
proper seal.
10. Insert the other retaining ring gasket (key 19) on top of the retaining ring.
11. Lower the upper cage (key 3B) into the valve. When properly installed, the raised ring on the bottom of the cage
should fit snugly into the groove formed by the seal rings and the retaining ring.
12. Place the spiral wound gasket (key 11), shim (key 22), and bonnet gasket (key 9), respectively, over the upper
cage.

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13. Mount the bonnet onto the valve with the lubricator or pipe plug parallel with the pipeline.
Note
Stud(s) and nut(s) should be installed such that the manufacturer's trademark and material grade marking is visible, allowing easy
comparison to the materials selected and documented in the Emerson/Fisher serial card provided with this product.
WARNING
Personal injury or damage to equipment could occur if improper stud and nut materials or parts are used. Do not operate or
assemble this product with stud(s) and nut(s) that are not approved by Emerson/Fisher engineering and/or listed on the
serial card provided with this product. Use of unapproved materials and parts could lead to stresses exceeding the design
or code limits intended for this particular service. Install studs with the material grade and manufacturer's identification
mark visible. Contact your Emerson representative immediately if a discrepancy between actual parts and approved parts
is suspected.
14. Lubricate the valve stud bolts (key 15) and install the nuts (key 16) onto the bolts using good bolting practices.
Tighten the nuts to the recommended bolt torques given in table 5. A pattern similar to that shown in figure 8
should be followed.
Note
It might be necessary to repeat the bolting pattern several times until the bonnet‐to‐body seal is made, because the tightening of
one nut might loosen an adjacent nut. Repeat the pattern until none of the nuts will turn at the recommended torque.
15. Mount the actuator on the bonnet and make up the stem connection according to the procedure given in the
appropriate actuator instruction manual.
YS
1. Use new gaskets and shim (keys 9, 11, 12, 13, 14 and 22) on assembly and wipe all sealing surfaces with a clean
cloth.
2. Install the lower seat ring gasket (key 14) and place the lower seat ring (key 8) on top of the gasket followed by the
spiral wound spring (key 13).
3. Install the lower cage (key 4) into the valve, being certain that it fits down over the raised portion of the seat ring.
The narrow portion of the cage windows should point downward.
4. Place the upper seat ring gasket (key 12) into the valve.
5. If a new stem (key 5) is to be used, screw the stem into the valve plug (key 2) until it wedges tight at the end of the
valve stem thread.
CAUTION
Never use an old stem with a new valve plug. The use of an old stem requires drilling a new pin hole through the stem (or
adaptor, in case an ENVIRO‐SEAL bellows seal bonnet is being used). This drilling weakens the stem or adaptor and may
cause failure in service. However, a used valve plug may be reused with a new stem or adaptor.

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Locate the pilot hole in the valve plug and drill the hole through the plug and stem assembly (determine drill size from
table 4). Drive in the pin to lock the assembly.
6. For ENVIRO‐SEAL bellows seal bonnets, grip the flats of the stem extending out of the top of the bellows shroud
with a soft‐jaw chuck or other type of vise. Screw the valve plug/adaptor assembly onto the valve stem. Tighten as
necessary to align the pin hole in the stem with one of the holes in the adaptor. Secure the adaptor to the stem with
a new pin.
7. Place the upper seat ring (key 7) and upper cage (key 3), respectively, over the plug and stem assembly, being
certain not to scratch any sealing surfaces. Lower this entire assembly into the valve.
8. Place the spiral wound gasket (key 11), shim (key 22), and bonnet gasket (key 9), respectively, over the upper cage.
9. Mount the bonnet onto the valve with the lubricator or pipe plug parallel with the pipeline.
Note
Stud(s) and nut(s) should be installed such that the manufacturer's trademark and material grade marking is visible, allowing easy
comparison to the materials selected and documented in the Emerson/Fisher serial card provided with this product.
WARNING
Personal injury or damage to equipment could occur if improper stud and nut materials or parts are used. Do not operate or
assemble this product with stud(s) and nut(s) that are not approved by Emerson/Fisher engineering and/or listed on the
serial card provided with this product. Use of unapproved materials and parts could lead to stresses exceeding the design
or code limits intended for this particular service. Install studs with the material grade and manufacturer's identification
mark visible. Contact your Emerson representative immediately if a discrepancy between actual parts and approved parts
is suspected.
10. Lubricate the valve stud bolts or cap screws (key 15) and install the nuts (key 16) onto the bolts using good bolting
practices. Tighten the nuts to the recommended bolt torques given in table 5. A pattern similar to that shown in
figure 8 should be followed.
Note
It might be necessary to repeat the bolting pattern several times until the bonnet‐to‐body seal is made, because the tightening of
one nut might loosen an adjacent nut. Repeat the pattern until none of the nuts will turn at the recommended torque.
11. Mount the actuator onto the bonnet and make up the stem connection according to the procedure given in the
appropriate actuator instruction manual.
ENVIRO‐SEAL Bellows Seal Bonnet
Replacing a Plain or Extension Bonnet with an ENVIRO‐SEAL Bellows Seal Bonnet
(Stem/Bellows Assembly)
1. Remove the actuator and bonnet according to steps 1 through 4 of the Disassembly procedure in the Maintenance
section on page 7.
2. With care, remove the valve plug and stem assembly from the valve. If necessary, also lift out the cage.

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CAUTION
To prevent possible product damage, cover the opening in the valve in the following procedure to protect the sealing
surfaces and to prevent foreign material from getting into the valve body cavity.
3. Remove and discard the existing bonnet gasket. Cover the valve body opening to protect sealing surfaces and to
prevent foreign material from entering the valve body cavity.
Note
The ENVIRO‐SEAL stem/bellows assembly for YD and YS valves is available only with a threaded and drilled plug/adaptor/stem
connection. The existing valve plug can be reused with the new stem/bellows assembly or a new plug can be installed.
4. Inspect the existing valve plug. If the plug is in good condition, it can be reused with the new ENVIRO‐SEAL
stem/bellows assembly. To remove the existing valve plug from the stem, first, place the existing plug stem
assembly and valve plug in a soft‐jaw chuck or other type of vise so that the jaws grip a portion of the valve plug that
is not a seating surface. Drive out or drill out the pin (key 8).
5. Reverse the plug stem assembly in the soft‐jaw chuck or vise. Grip the valve stem in an appropriate place and
unscrew the existing plug from the valve stem.
CAUTION
When installing a valve plug on the ENVIRO‐SEAL stem/bellows assembly, the valve stem must not be rotated. Damage to
the bellows may result.
Do not grip the bellows shroud or other parts of the stem/bellows assembly. Grip only the flat areas on the stem where it
extends out of the top of the bellows shroud.
Note
The ENVIRO‐SEAL stem/bellows assembly has a one‐piece stem.
6. To attach the valve plug to the stem of the new ENVIRO‐SEAL stem/bellows assembly, first attach the plug to the
adaptor (key 24). Locate the adaptor. Notice that a hole has not been drilled in the threads where the plug screws
onto the adaptor. Secure the valve plug in a soft‐jaw chuck or other type of vise. Do not grip the plug on any seating
surface. Position the plug in the chuck or vise for easy threading of the adaptor. Thread the adaptor into the valve
plug and tighten to the appropriate torque value.
7. Select the proper size of drill bit and drill through the adaptor using the hole in the valve plug as a guide. Remove
any metal chips or burrs and drive in a new pin to lock the plug/adaptor assembly together.
8. Attach the plug/adaptor assembly to the ENVIRO‐SEAL stem/bellows assembly by first securing the stem/bellows
assembly in a soft‐jaw chuck or other type of vise so that the jaws of the chuck or vise grip the flats of the stem
extending out of the top of the bellows shroud. Screw the valve plug/adaptor assembly onto the valve stem.
Tighten as necessary to align the pin hole in the stem with one of the holes in the adaptor. Secure the adaptor to the
stem with a new pin.
9. Inspect the seat ring (key 9) and soft seat parts (keys 21, 22, and 23); replace, if necessary.
10. Place a new gasket (key 10) into the valve in place of the bonnet gasket. Install the new stem/bellows assembly
with valve plug/adaptor by placing it into the valve on top of the new bellows gasket.

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11. Place a new gasket (key 22) over the stem/bellows assembly. Place the new ENVIRO‐SEAL bonnet over the
stem/bellows assembly.
Note
Stud(s) and nut(s) should be installed such that the manufacturer's trademark and material grade marking is visible, allowing easy
comparison to the materials selected and documented in the Emerson/Fisher serial card provided with this product.
WARNING
Personal injury or damage to equipment could occur if improper stud and nut materials or parts are used. Do not operate or
assemble this product with stud(s) and nut(s) that are not approved by Emerson/Fisher engineering and/or listed on the
serial card provided with this product. Use of unapproved materials and parts could lead to stresses exceeding the design
or code limits intended for this particular service. Install studs with the material grade and manufacturer's identification
mark visible. Contact your Emerson representative immediately if a discrepancy between actual parts and approved parts
is suspected.
12. Properly lubricate the bonnet stud bolts. Install and tighten the bonnet hex nuts to the proper torque.
13. Install new packing and the metal packing box parts according to the appropriate arrangement in figure 17 or 18.
14. Install the packing flange. Properly lubricate the packing flange stud bolts and the faces of the packing flange nuts.
For graphite packing, tighten the packing flange nuts to the maximum recommended torque shown in table 6. Then,
loosen the packing flange nuts, and retighten them to the recommended minimum torque shown in table 6.
For other packing types, tighten the packing flange nuts alternately in small equal increments until one of the nuts
reaches the minimum recommended torque shown in table 6. Then, tighten the remaining flange nut until the
packing flange is level and at a 90‐degree angle to the valve stem.
15. Install travel indicator parts and stem locknuts; mount the actuator onto the valve according to the procedure in
the appropriate actuator instruction manual.
Replacement of an Installed ENVIRO‐SEAL Bellows Seal Bonnet (Stem/Bellows Assembly)
1. Remove the actuator and bonnet according to steps 1 through 4 of the Disassembly procedure in the Maintenance
section on page 7.
CAUTION
To prevent possible product damage, cover the opening in the valve in the following procedure to protect the sealing
surfaces and to prevent foreign material from getting into the valve body cavity.
2. Carefully remove the ENVIRO‐SEAL stem/bellows assembly. If necessary, also lift out the cage. Remove and discard
the existing bonnet gasket and bellows gasket. Cover the valve body opening to protect sealing surfaces and to
prevent foreign material from entering the valve body cavity.
CAUTION
The ENVIRO‐SEAL stem/bellows assembly for YD and YS valves is available only with a threaded and drilled
plug/adaptor/stem connection. The existing valve plug can be reused with the new stem/bellows assembly or a new plug

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can be installed. If the existing valve plug is reused, and the adaptor is in good condition, it may also be reused. However,
never reuse an old adaptor with a new valve plug. Using an old adaptor with a new valve plug requires drilling a new pin
hole in the adaptor. This drilling weakens the adaptor and may cause failure in service. However, a used valve plug may be
reused with a new adaptor.
3. Inspect the existing valve plug and adaptor. If they are in good condition, they can be reused with the new
stem/bellows assembly and they do not need to be separated.
CAUTION
When removing/installing a valve plug on the ENVIRO‐SEAL stem/bellows assembly, the valve stem must not be rotated.
Damage to the bellows may result.
Do not grip the bellows shroud or other parts of the stem/bellows assembly. Grip only the flat areas on the stem where it
extends out of the top of the bellows shroud.
Note
The ENVIRO‐SEAL stem/bellows assembly has a one‐piece stem.
4. If the valve plug and adaptor are not in good condition and must be replaced, first remove the valve plug/adaptor
assembly from the stem/bellows assembly; then remove the valve plug from the adaptor. First, place the
stem/bellows assembly and valve plug in a soft‐jaw chuck or other type of vise so that the jaws grip a portion of the
valve plug that is not a seating surface. Drive out or drill out the pin (key 6, figure 9, 10, or 11. Drive out the pin (key
36, figure 15).
Table 6. Recommended Torque for Fisher ENVIRO‐SEAL Bellows Seal Packing Flange Nuts
VALVE
SIZE,
NPS
VALVE STEM DIAMETER
THROUGH PACKING
MINIMUM TORQUE MAXIMUM TORQUE
NSm LbfSin NSm LbfSin
1/2 ‐ 2 1/2 3 24 5 48
3 ‐ 4 1 7 60 10 84
5. Reverse the stem/bellows and plug/adaptor assembly in the soft‐jaw chuck or vise. Grip the flat areas on the valve
stem just below the threads for the actuator/stem connection. Unscrew the plug/adaptor assembly from the
stem/bellows assembly. Unscrew the valve plug from the adaptor.
6. To attach either the existing valve plug or a new one to the stem of the new ENVIRO‐SEAL stem/bellows assembly,
first attach the plug to the adaptor (if the valve plug was removed from the adaptor) as follows:
D Locate the adaptor. Notice that a hole has not been drilled in the threads where the plug screws onto the adaptor.
D Secure the valve plug in a soft‐jaw chuck or other type of vise. Do not grip the plug on any seating surface. Position
the plug in the chuck or vise for easy threading of the adaptor.
D Thread the adaptor into the valve plug and tighten to the appropriate torque value.
7. Complete the installation by following steps 7 through 9 and steps 12 through 15 of the ENVIRO‐SEAL Bellows Seal
Bonnet installation instructions given above.
Purging the ENVIRO‐SEAL Bellows Seal Bonnet
The ENVIRO‐SEAL bellows seal bonnet can be purged or leak tested. Refer to figure 15 for an illustration of an
ENVIRO‐SEAL bellows seal bonnet, and perform the following steps for purging or leak testing.

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1. Remove the two diametrically opposed pipe plugs (key 16).
2. Connect a purging fluid to one of the pipe plug connections.
3. Install appropriate piping or tubing in the other pipe plug connection to pipe away the purging fluid or to make a
connection to an analyzer for leak testing.
Figure 9. Fisher YS Valve
30A3554‐D
COMMON PORT