Emerson Fisher EWNS User manual

www.Fisher.com
Fisher™EWNS Control Valve
Contents
Introduction 1.................................
Scope of Manual 1.............................
Description 1.................................
Specifications 1...............................
Educational Services 3.........................
Principle of Operation 3.........................
Lifting Guidelines 3.............................
Installation 4..................................
Maintenance 5.................................
Bonnet Nut Torquing Considerations 6...........
Packing Lubrication 7..........................
Packing Maintenance 7.........................
Replacing HIGH-SEAL Packing 8..............
Trim Removal 12..............................
Trim Replacement 13..........................
Troubleshooting 17.............................
Parts Ordering 20...............................
Parts List 20...................................
Figure 1. EWNS Valve with Piston Actuator
Introduction
Scope of Manual
This instruction manual includes installation, maintenance, and parts information for NPS 20x16 and NPS 22x16 EWNS
valves with CL900 ratings. Note: Applications requiring lower pressure class ratings may use the same casting as a
higher rated valve of the required size. Refer to separate manuals for instructions covering the actuator, positioner,
and accessories.
Do not install, operate, or maintain EWNS 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 before proceeding.
Description
NPS 20X16 EWNS valves (figure 1) have schedule 120 buttweld end connections and NPS 22X16 EWNS valves have
schedule 140 buttweld end connections. EWNS valves are designed for use with a Fisher yoke and buyout piston
actuator and can also be used with Fisher 667NS2 and 657NS2 actuators. EWNS valves are designed to handle high
seismic environments.
Specifications
Specifications for EWNS valves are shown in table 1.
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Table 1. Specifications
Valve Sizes
JNPS 20x16 JNPS 22x16 (size designation is end
connection size x nominal trim size)
Maximum Temperature and Pressure(1)
-29 to 316_C (-20 to 600_F), CL900 maximum
End Connection Styles and Ratings(1,2)
Buttwelding: Consistent with Schedule 120 or 140
Flanges: Not available
Socket Welding: Not available
Also see table 2
Shutoff Classifications
Bidirectional Anti-extrusion Seal Trim: Class V.
See table 3
Flow Characteristic
Standard Cage: Equal percentage
Special cages: Special characterized flow cages are
available. Consult your Emerson sales office.
Flow Direction
Standard Cage: EWNS Balanced — normally flow
down(3)
Approximate Weights (valve body and bonnet
assemblies)
See table 2
Bolt Torque Tolerance
Torque values given are +/- 5%, unless otherwise
specified
Special Tools
Standard mechanics tools are used for
assembly/disassembly
Additional Specifications
For specifications such as materials, valve plug
travels, and port, yoke bolt circle, and stem
diameters, see the Parts List section
1. The pressure or temperature limits in this manual and any applicable standard limitations should not be exceeded.
2. EN (or other) ratings and other BWE can usually be supplied; consult your Emerson sales office.
3. May be used flow up as required by design.
Table 2. Valve Assembly Approximate Weights
VALVE SIZE, NPS PRESSURE RATING KILOGRAMS POUNDS
20x16 900 3305 7270
22x16 3590 7900
Table 3. Shutoff Classifications per ANSI/FCI 70‐2 and IEC 60534‐4
VALVE DESIGN VALVE SIZE, NPS PORT DIAMETER, mm
(INCHES) CAGE STYLE LEAKAGE CLASS
Balanced EWNS 20x16 374.65 (14.75) Equal Percentage V (forward)/
IV (reverse)
22x16
Table 4. Torque for Body‐to‐Bonnet Bolting Using Nuclear Grade Anti-Seize Lubricant
VALVE
RATING
VALVE
SIZE,
NPS
TORQUE
NSm lbfSft
B7 Studs B7 Studs
All 20x16 2915 2150
22x16

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Educational Services
For information on available courses for the Fisher EWNS valve, 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
Principle of Operation
EWNS valves are control valves based on the Fisher EW valve product. The valve body and bonnet contain a fluid under
pressure, while the internal valve parts control the flow of the fluid through the valve. The internal parts consist of
gaskets, a cage-seat ring assembly, a plug-stem assembly, and bidirectional seal rings for both cage-seat ring assembly
and plug-stem assembly. The gaskets and cage-seat ring assembly are stationary and held in place inside the valve
body and bonnet by the force applied by the body-to-bonnet bolting. The plug-stem assembly is designed to move up
and down (axially) inside the cage. The stem passes through a hole in the bonnet, and can be moved up and down
(axially) by an external actuator attached to the bonnet. Packing is used between the valve bonnet and plug stem to
prevent the fluid from leaking out of the valve, while still allowing the plug stem to move axially.
Fluid enters one end of the valve. When the stem is pushed down, the plug moves to contact the seat ring, and "closes"
the valve, preventing the fluid from passing through the valve. When the stem is pulled up, the plug disengages from
the seat ring, and slides up through the center of the cage, exposing holes or flow passages in the cage. This allows the
fluid to flow through the seat ring and cage, and exit the valve through the opposite end of the valve which it entered.
By positioning the plug at different "travels" in the cage, the amount of flow through the valve can be controlled.
Lifting Guidelines
WARNING
Failure to follow these lifting guidelines and accepted lifting and rigging practices could result in property damage and
personal injury or death.
All lifting and rigging must be completed in accordance with federal/national/provincial, state and local regulations and
applicable lifting and rigging equipment standards. Only personnel trained in proper lifting and rigging practices shall
perform valve/actuator assembly lifting, rigging and installation. Because each lift will be unique, the method of lifting the
valve assembly, the correct location for attaching and lifting the valve assembly, and what the valve assembly will do when
lifted shall be considered for each lift.
Lifting and rigging equipment used to lift, install or remove a valve assembly or component must be properly selected and
sized for the weight and configuration of the valve assembly or component being lifted. The weight of the complete valve
assembly, including attached accessories, must be taken in consideration for this purpose. The lifting and rigging
equipment must be properly maintained and inspected for damage before each use.
If the valve is supplied with an actuator or handwheel, do not use the actuator or handwheel to lift the complete valve
assembly. Lifting lugs attached to the actuator must not be used to lift the complete valve assembly unless clearly marked
as being rated to support the complete valve assembly weight.
Lifting lugs or other lifting equipment attached to the valve or actuator must never be used to lift or support the weight of
attached piping.

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CAUTION
Care must be taken when lifting the valve/actuator assembly to ensure all accessories and tubing are not damaged in the
process. Accessories and tubing may need to be removed prior to lifting to prevent damage and properly reinstalled before
use. Protect valve flange faces, butt weld ends, and other connection surfaces from damage during lifting.
The quantity of eyebolts for lifting purpose is the minimum recommendation. More eyebolts can be used per customer
experience. When tightening the eyebolts and nuts, do not exceed the torque that is specified on the diaphragm casing cap
screws and nuts (keys 119 and 120) in the following sections, to avoid damage on the diaphragm.
Lifting Valve/Actuator Assembly
To lift the EWNS valve assembly, ATI L264.5SRE80 actuator and accessories, the lifting ears located on the upper
cartridge should not be used alone. It is also necessary to place lifting slings around the inlet and outlet of the valve
body for lifting. Use padding as needed to protect any painted surfaces. The valve/actuator assembly can be lifted
using a hoist capable of leveling the lifting points.
Lifting Valve Only
To lift the valve, eyebolts should be used. Insert 1-1/8-8 inch shouldered pattern eyebolts into four threaded holes
located on the top of the valve bonnet, positioned 90 degrees apart. The eyebolt material should be ASTM
A489-K04800 or stronger material. Be sure at least 90% of the threads are engaged in the receiving hole, with a
minimum thread engagement of at least 1-1/2 times the thread diameter in steel. If necessary, place lifting slings
around the inlet and outlet of the valve body for stabilization. Use padding as needed to protect any painted surfaces.
The valve can now be lifted using a hoist capable of leveling the lifting points.
Lifting Actuator Only
The ATI L264.5SRE80 actuator with accessories may be lifted using the lifting ears located on the upper cartridge. A
single hoist lift point on the strap or chain will balance and lift the actuator, keeping it level. Use padding as needed to
protect any painted surfaces.
Installation
WARNING
Always wear protective gloves, clothing, and eyewear when performing any installation operations to avoid personal
injury.
Personal injury or equipment damage caused by sudden release of pressure may 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 over‐pressure 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.
WARNING
Some bonnet flanges have a tapped hole that was used to handle the bonnet during manufacture. Do not use this tapped
hole to lift the valve assembly or personal injury may result.

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WARNING
The valve configuration and construction materials were selected to meet particular pressure, temperature, pressure drop,
and controlled fluid conditions indicated when the valve was ordered. Responsibility for the safety of process media and
compatibility of valve materials with process media rests solely with the purchaser and end‐user. To avoid possible
personal injury and because 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.
1. Before installing the valve, inspect it to ensure that the valve body (key 1) cavity is free of foreign material.
2. Clean out all pipelines to remove scale, welding slag, and other foreign materials before installing the valve.
3. Flow through the valve must be in the direction indicated by the flow arrow, which is stamped on or attached to the
valve body.
CAUTION
Depending on valve body materials used, post‐weld heat treating might be needed. Post‐weld heat treatment can damage
internal elastomeric, plastic, and metal parts. Shrink‐fit pieces and threaded connections might also loosen. In general, if
post‐weld heat treating is needed, remove all trim parts. Contact your Emerson sales office for additional information.
4. Install the valve in the line. Use accepted piping and welding practices when installing the valve in the pipeline.
5. Install a three‐valve bypass around the valve if continuous operation is required during maintenance.
6. After installing the valve, inspect it once again to ensure that the valve body cavity is free and clear of foreign
material to avoid damaging any internals.
7. If the actuator and valve body are shipped separately, refer to the actuator mounting procedure in the appropriate
actuator instruction manual.
8. If the valve body was shipped without packing installed in the packing box, install the packing before putting the
valve body into service. Refer to instructions given in the Packing Maintenance procedure.
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. Please read and follow the packing adjustment
procedures in the Packing Maintenance section 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 packing maintenance
and trim maintenance. All maintenance operations may be performed with the valve in the line.

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WARNING
Avoid personal injury or damage to property from sudden release of pressure or uncontrolled process fluid. Before starting
disassembly:
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.
D Use bypass valves or completely shut off the process to isolate the valve from process pressure. Relieve process pressure
on 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.
D Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
Note
The EWNS valve uses spiral‐wound gaskets (key 5) which are crushed to provide their seal. A spiral‐wound gasket should never be
reused. Whenever a gasket seal is disturbed by removing or shifting gasketed parts, a new gasket must be installed upon
reassembly. This is necessary to ensure a good gasket seal, since the used gasket will not seal properly.
CAUTION
The spiral‐wound gaskets (key 5) are of special design. Failure to use genuine Fisher replacement parts may result in valve
damage.
Note
If the valve has HIGH‐SEAL Heavy‐Duty live‐loaded packing installed (figure 3), see the Replacing HIGH‐SEAL Packing section in this
manual for packing instructions.
Bonnet Nut Torquing Considerations
When using a hydraulic torque wrench to tighten the bonnet nuts, use an extra socket or some other form of tooling
to prevent the reaction arm from contacting the adjacent bonnet nut. This will help prevent damage to the bonnet nut
faces. See figure 2 for a diagram of this procedure.

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Figure 2. Procedure to Prevent Marring of Bonnet Nuts During Assembly
HYDRAULIC TORQUE WRENCH
REQUIRED SOCKET
EXTRA TOOLING
TO PROTECT
THE ADJACENT NUT
REACTION ARM
X0644
Packing Lubrication
Note
No provisions for packing lubrication.
WARNING
Do not lubricate any parts or surfaces that may come into contact with the process media. Any use of lubricant can lead to
the contamination of the process media and could lead to property damage or failure.
Packing Maintenance
If there is undesirable packing leakage in HIGH-SEAL packing, first try to limit the leakage and establish a stem seal by
tightening the packing flange nuts (key 14, figure 9) to at least the minimum spring load shown in figure 6. However,
do not exceed the maximum spring load shown in figure 6 or excessive friction may result. If leakage continues,
replace the packing by following the numbered steps presented in the Replacing HIGH-SEAL Packing procedure.
If the packing is relatively new and tight on the valve plug stem (key 4), and if tightening the packing flange nuts (key
14) does not stop the leakage, it is possible that the stem is worn or nicked so that a seal cannot be made. The surface
finish of a new stem is critical for making a good packing seal. If the leakage comes from the outside diameter of the
packing, it is possible that the leakage is caused by nicks or scratches around the packing box wall. While replacing the
packing according to the Replacing HIGH-SEAL Packing procedure, inspect the valve plug stem and packing box wall
for nicks or scratches.

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Replacing HIGH-SEAL Packing
WARNING
Refer to the WARNING at the beginning of the Maintenance section in this instruction manual.
Key numbers referred to in this procedure are shown in figure 3 or 9, unless otherwise indicated.
1. Isolate the control valve from the line pressure, release pressure from both sides of the valve body (key 1), and drain
the process media from both sides of the valve. If using a power actuator, also shut‐off all pressure lines to the
power actuator, release all pressure from the actuator. Use lock‐out procedures to be sure that the above measures
stay in effect while you work on the equipment.
2. Exhaust all actuator pressure, if any was applied, and disconnect the actuator supply and any leakoff piping.
3. Using the appropriate actuator instruction manual for reference, relieve all spring compression from the actuator.
4. Remove the cap screws in the stem connector, and separate the two halves of the stem connector.
5. Remove the actuator-to-bonnet hex nuts, and remove the actuator from the bonnet (key 10).
6. Loosen the packing flange nuts (key 14) so that the packing (figure 3) is not tight on the valve plug stem (key 4).
Remove any stem locknuts from the valve plug stem threads.
CAUTION
Avoid damage to the seating surfaces caused by the valve plug and stem assembly (key 4) dropping from the bonnet (key
10) after being lifted part way out. When lifting the bonnet (key 10), either be sure that the valve plug and stem assembly
(key 4) remain in the valve and on the seat ring (key 3) or, temporarily install a valve stem locknut on the valve stem. This
locknut will prevent the valve plug and stem assembly from dropping out of the bonnet.
Use care to avoid damaging gasket sealing surfaces.
Figure 3. PTFE HIGH-SEAL Packing

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WARNING
To avoid personal injury or property damage caused by uncontrolled movement of the bonnet (key 10), loosen the bonnet
by following the instructions in the next step. Do not remove a stuck bonnet by pulling on it with equipment that can
stretch or store energy in any other manner. The sudden release of stored energy can cause uncontrolled movement of the
bonnet. If the cage sticks to the bonnet, proceed carefully with bonnet removal and support the cage so that it will not fall
unexpectedly from the bonnet.
Note
The following step also provides additional assurance that the valve body fluid pressure has been relieved.
7. Hex nuts (key 8) and washers (key 24) attach the bonnet (key 10) to the valve body (key 1). Loosen these nuts
approximately 3 mm (1/8 inch). Then loosen the body‐to‐bonnet gasketed joint by either rocking the bonnet or
prying between the bonnet and valve body. Work the prying tool around the bonnet until the bonnet loosens. If no
fluid leaks from the joint, proceed to step 9.
8. If leakage does occur from the joint, tighten the nuts (key 8) and verify that the process is properly shut down or the
valve is properly bypassed.
9. Unscrew the hex nuts (key 8), remove the washers (key 24), and carefully lift the bonnet (key 10) off the valve stem.
If the valve plug and stem assembly (key 4) starts to lift with the bonnet, use a deadblow hammer on the end of the
stem and tap it back down. Set the bonnet on a cardboard or wooden surface to prevent damage to the bonnet
gasket surface.
10. Remove the cage gasket (key 5). Lift the valve plug and stem assembly (key 4) out of the valve body and set it on a
protective surface. If the valve plug is to be reused, protect the valve plug seating surface to prevent scratches.
Install screws or bolts into the tapped holes in the top of the cage (key 2), and carefully lift the cage and seat ring
(key 3) assembly out of the valve body. Remove the other cage gasket (key 5).
CAUTION
Inspect the cage, bonnet, and body gasket surfaces. These surfaces must be in good condition, with all foreign material
removed. Small burrs less than approximately 0.076 mm (0.003 inches) in height (the thickness of a human hair) can be
ignored. Scratches or burrs that run across the serrations are not permitted under any conditions, since they will prevent
the gaskets from sealing properly.
11. Clean all gasket seating surfaces; refer to your process or safety engineer for appropriate cleaning tools. Clean in
the same direction as the surface serrations, not across them.
12. Cover the opening in the valve body to protect the gasket seating surface and to prevent foreign material from
getting into the valve body cavity.
13. Remove the packing flange nuts (key 14), packing flange (key 9), qty 2 Belleville springs (key 20), indicator disk (key
19), packing follower (key 17), qty-4 load scale mounting screws (key 21), and load scale (key 22). Carefully push
out all the remaining packing parts from the valve side of the bonnet using a rounded rod or other tool that will not
scratch the packing box wall.
14. Clean the packing box and the following metal packing parts: packing follower (key 17), packing box ring (key 11).
15. Inspect the valve stem threads and packing box surfaces for any sharp edges that might cut the packing. Scratches
or burrs could cause packing box leakage or damage to the new packing. If the surface condition cannot be
improved by light sanding or honing with a tool similar to a small honing stone, replace the damaged parts.

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16. Remove the protective covering from the valve body cavity, and install the seat ring and cage using qty-2 new cage
gasket (key 5). Install the plug, then slide the bonnet over the stem and onto the studs (key 7).
Note
The proper bolting procedures in step 17 include‐‐but are not limited to‐‐ensuring that the bonnet stud threads are clean, and that
the hex nuts are evenly tightened to the specified torque values.
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. Contact your Emerson sales office immediately if a discrepancy between
actual parts and approved parts is suspected.
CAUTION
Failure to comply with good bonnet‐to‐body bolting practices and the torque values shown in table 4 may result in damage
to the valve. Cheater bars or slug wrenches should not be used for this procedure.
Hot torquing is not recommended.
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.
17. Lubricate the stud threads (key 7) and the seating faces of the hex nuts (key 8) with Nuclear Grade anti-seize
lubricant (key 27). Install the washers (key 24) over the bonnet studs (key 7). Replace the hex nuts and tighten them
finger‐tight. Stroke the valve several times to center the trim. Torque the nuts in a crisscross pattern (reference
figure 5) to no more than 1/4 of the nominal torque value specified in table 4.
Note
If using a hydraulic torque wrench, please see the Bonnet Nut Torquing Considerations section to help prevent damage to parts.
When all nuts (key 8) are tightened to that torque value, increase the torque by 1/4 of the specified nominal torque
and repeat the crisscross pattern. Repeat this procedure until all nuts are tightened to the specified nominal value.
Apply the final torque value again and, if any nut still turns, tighten every nut again.
Note
When installing packing rings (key 13 and key 16), prevent entrapping air between the rings. Add the rings one at a time without
forcing them below the chamfer of the packing box (key 11) entrance chamber. As each successive ring is added, the stack should
not be pushed down more than the thickness of the added ring (figure 4).

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Figure 4. Installing Graphite Ribbon/Filament Packing Rings One at a Time
VALVE STEM
PACKING
FOLLOWER
BONNET
TOP OF
PACKING RING
EVEN WITH
BOTTOM OF
ENTRANCE
CHAMFER
INSTALLING
SECOND PACKING RING
A2207‐2
INSTALLING
FIRST PACKING RING
18. Install new packing and the metal packing box parts according to the appropriate arrangement in figure 3. Place a
smooth-edged pipe over the valve stem (key 4), the top end higher than the valve stem is recommended. An
alternative way is to slide the packing follower (key 17) over the valve stem. Gently tap each soft packing part into
the packing box one piece at a time, being sure that air is not trapped between adjacent soft parts.
Note
Be sure to install the packing rings in the sequence shown in figure 3.
19. Install the packing follower (key 17).
20. Place the indicator disk (key 19) and the first Belleville spring (key 20) while guiding them onto the packing follower
(key 17). Make certain the convex side of the Belleville spring is towards the indicator disk as shown in figure 3.
21. Place the second Belleville spring (key 20) with the convex side toward the packing flange (key 9); see figure 3.
Position the packing flange on top of the spring, making sure the second spring fits into its guide in the flange.
CAUTION
Keep the packing follower (key 17) and flange (key 9) centered on the valve stem (key 4). If any metal part makes contact
with the stem, it can cause damage to the stem surface. Vertical scratches or nicks on the stem surface can cause excessive
leakage from the packing.

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Figure 5. Bolting Diagram
Figure 6. Typical Load Scale
A4990‐2
ZERO SPRING LOAD
(PACKING NUTS FINGER‐TIGHT)
MINIMUM SPRING LOAD
MAXIMUM SPRING LOAD
STEM SIZE
22. Lubricate the packing nuts (key 14) with Nuclear Grade anti-seize lubricant (key 27) and tighten them hand‐tight.
23. The load scale (key 22) is used to indicate compression on the Belleville springs. Position the qty-2 load scales (key
22) by slightly loosening the mounting screws (key 21). Align the bottom edge of the load scale with the indicator
disk and retighten the screws. Figure 6 illustrates the load scale properly adjusted before the nuts have been
tightened and with the Belleville springs (key 20) not compressed.
24. Tighten the packing nuts (key 14) while observing the two load scales (key 22) to make sure the flange (key 9) is
tightened evenly. Be sure to keep the follower (key 17) centered on the stem (key 4) while tightening the nuts.
Tighten the nuts alternately and evenly, keeping the flange parallel with the valve, until the indicator disk (key 19)
aligns with the maximum compression line on the load scales.
25. The packing is now properly loaded and the packing nuts (key 14) do not need to be retightened unless the
indicator (key 19) begins to approach the minimum compression line. After the valve has been in service for awhile,
visually check the load scale to determine loading. Under normal conditions, the packing nuts should not require
retightening for the life of the packing.
Trim Removal
Key numbers referenced in this procedure are shown in figure 9 except where indicated.
1. Remove the actuator and bonnet by following steps 1 through 9 of the replacing packing procedure. Observe all
warnings and cautions.

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CAUTION
Use care to avoid damaging gasket surfaces.
The surface finish of the valve stem (key 4) is critical for making a good packing seal. The inside surface of the cage or cage
assembly (key 2) is critical for smooth operation of the valve plug and for making a seal with the bidirectional
anti-extrusion seal rings (key 31). The seating surfaces of the valve plug (key 4) and seat ring (key 3) are critical for proper
shutoff. The inside surface of the valve body port is critical for making a seal with the anti-extrusion rings (key 35) and the
spring-loaded seal rings (key 36). Assume all these parts are in good condition, and protect them accordingly unless
inspection reveals otherwise.
To avoid leakage when the valve is returned to service, use appropriate methods and materials to protect all sealing
surfaces of the trim parts during maintenance.
2. Remove the plug/stem assembly (key 4) (with bidirectional anti-extrusion seal rings [key 30]) from the valve body. If
the valve plug/stem assembly is to be reused, tape or otherwise protect the valve plug stem and the valve plug
seating surface to prevent scratches.
3. Use an appropriate tool and carefully remove the retainer ring (key33) from the valve plug (key 4).
4. Use an appropriate tool to pry the remaining qty-1 backup ring (key 29), qty-2 anti-extrusion ring (key 30), qty-2
spring loaded seal ring (key 31), and qty-1 spacer ring (key 32) from the top of the plug. Use caution to avoid
scratches or other damage to the sealing surfaces where the bidirectional seal plug seal makes contact with the
valve plug (figure 8).
5. Remove the cage gasket (key 5). Install screws or bolts into the tapped holes in the top of the cage/seat ring
assembly (key 2), and carefully lift it out of the valve body. Remove the other cage gasket (key 5).
6. Inspect the seal rings (key 35) on the seat ring (key 3), and remove them in the same way as specified in step 2 and 3
if replacement is necessary. Use caution to avoid scratches or other damage to the sealing surfaces where the
bidirectional anti-extrusion seal rings make contact with the seat ring (figure 7).
7. The seat ring (key 3) is screwed into the cage and secured with four set screws (key 28). Remove all set screws.
8. There are two 3/8-inch UNC tapped holes in the bottom of the seat ring (key 3). Screw cap screws into these holes.
Use a bar to pry against the cap screws and turn the seat ring out of the cage.
9. Inspect the lower seating surface where the valve plug (key 4) contacts the seat ring (key 3) for wear or damage
which would prevent proper operation of the valve. Inspect the sealing surface inside the cage where the
bidirectional anti-extrusion seal rings (keys 30 and 35) contact the cage (key 2), and inspect the sealing surface
where the anti-extrusion seal rings make contact with the plug (figure 8). Also, inspect the sealing surface outside
the seat ring where the bidirectional anti-extrusion seal rings contact the seat ring, and inspect the sealing surface
where the bidirectional anti-extrusion seal rings make contact with the valve body (figure 7).
Trim Replacement
WARNING
Observe the warning at the start of the Maintenance section.
After all trim maintenance has been completed, reassemble the valve body (key 1) by following the numbered steps
below. Be certain that all gasketed surfaces have been well cleaned. Key numbers referenced in this procedure are
shown in figure 9, except where indicated.

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CAUTION
Inspect the cage (key 2), bonnet (key 10), and body gasket seating surfaces. These surfaces must be in good condition, with
all foreign material removed. Small burrs less than approximately 0.076 mm (0.003 inches) in height (the thickness of a
human hair) can be ignored. Scratches or burrs that run across the serrations are not permitted under any conditions, since
they will prevent the gaskets from sealing properly.
If replacing the valve plug spring loaded seal ring (key 31) and seat ring spring loaded seal ring (key 36), be careful not to
scratch the surfaces of the ring groove in the valve plug and seat ring or any of the surfaces of the replacement ring, or the
replacement ring may not seal properly.
1. Place the seat ring (key 3) on the platform with the bigger outside diameter side upward. Note the orientation of
the spring-loaded seal ring open side in figure 7. Slide qty-1 anti-extrusion ring (key 35), qty-1 spring loaded seal
ring (key 36), qty-1 spacer ring (key 37), qty-1 spring loaded seal ring (key 36), qty-1 anti-extrusion ring (key 35),
and qty-1 backup ring (key 38) into the seat ring with the orientation shown in figure 7. Install the retainer ring (key
39) into the groove of the seat ring (key 3).
2. Screw two eye bolts into the two 3/8-16UNC tapped holes in the bottom of the seat ring (key 3). Use a bar to get
through the holes of the two eye bolts, and rotate the bar to turn the seat ring into the bottom of the cage (key 2)
until the bottom surface of the cage (key 2) contacts the seat ring (key 3).
3. Secure the seat ring (key 3) with four set screws (key 28) by installing the set screws (key 28) into four holes in the
cage (key 2). Thread the set screws until no more engagement can be obtained. The maximum allowed protrusion
out of the cage is about 0.04 inches.
4. Install qty-1 cage spiral wound gasket (key 5) in the gasket groove in the top of the valve body (key 1), making sure
the bottom of the gasket is flush with the mating surface in the body.
5. Install the cage/seat ring assembly into the valve body trim bore. When installing the assembly, take care to ensure
that the bottom diameter guides properly and the shoulder of the cage sits flush against the spiral wound gasket
(key 5).
6. Inspect the sealing surface of the plug/stem assembly (key 4) for nicks and scratches. Install qty-1 anti-extrusion
ring (key 30), qty-1 spring loaded seal ring (key 31), qty-1 spacer ring (key 32), qty-1 spring loaded seal ring (key
31), qty-1 anti-extrusion ring (key 30) and qty-1 backup ring (key 29) onto the top of the plug with the orientation
shown in figure 8. Install the retainer ring (33) into the groove on top of the plug.
Note
To install the spring-loaded seal ring, gently stretch the seal ring and work it over the edge of the valve plug or seat ring. Give the
PTFE material in the seal ring time to cold flow during the stretching procedure. Avoid jerking sharply on the ring. Stretching the
seal ring over the valve plug or seat ring might make it seem loose when it is in the groove, but it will shrink to its original size after
you have installed the plug and seat ring.
7. Slide the valve plug/ stem (key 4) assembly into the cage (key 2). Make sure the valve plug seal ring (key 30) is
evenly engaged in the entrance chamfer at the top of the cage or cage assembly to avoid damaging the ring. Gently
rest the plug seating surface against the seat ring (key 3).
8. Install qty-1 cage spiral wound gasket (key 5) on the cage (key 2) in the groove formed by the valve body (key 1) and
cage.

Instruction Manual
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EWNS Valve
March 2022
15
9. Lubricate the bonnet stud with Nuclear Grade anti-seize lubricant (key 27). Install the bonnet (key 10) over the
bonnet studs (key 7) and onto the valve body (key 1), with the Fisher logo on the bonnet on same side as the Fisher
logo on the body. The cage will center the bonnet.
Note
The proper bolting procedures include -- but are not limited to -- ensuring that the bonnet stud threads are clean, and that the hex
nuts are evenly tightened to the specified torque values.
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. Contact your Emerson sales office immediately if a discrepancy between
actual parts and approved parts is suspected.
CAUTION
Failure to comply with good bonnet-to-body bolting practices and the torque values shown in table 4 may result in damage
to the valve. Cheater bars or slug wrenches should not be used for this practice.
Hot torquing is not recommended.
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.
10. Lubricate the stud threads and the faces of the hex nuts (key 8) with nuclear grade anti-seize lubricant (key 27).
Install the washers (key 24) over the bonnet studs (key 7). Replace the hex nuts, but do not tighten them. Torque
the nuts in a crisscross pattern (as shown in figure 5) to no more than 1/4 of the nominal torque value specified in
table 4. When all nuts are tightened to that torque value, increase the torque by 1/4 of the specified nominal torque
and repeat the crisscross pattern. Repeat this procedure until all nuts are tightened to the specified nominal value.
Apply the final torque value again and, if any nut still turns, tighten every nut again.
Note
If using a hydraulic torque wrench, please see the Bonnet Nut Torquing Considerations section to help prevent damage to parts.
11. Install new packing and packing box parts per steps 18 and 25 of the Replacing Packing procedure. Be certain to
observe the note given prior to step 18 of that procedure.
12. Mount the actuator on the valve body assembly, and reconnect the actuator and valve plug stems according to the
procedures in the appropriate actuator instruction manual. Check for packing leakage as the valve is being put into
service.

Instruction Manual
D103551X012
EWNS Valve
March 2022
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Figure 7. Seat Ring Using Bidirectional Seal Rings
Figure 8. Plug Using Bidirectional Seal Rings

Instruction Manual
D103551X012
EWNS Valve
March 2022
17
Troubleshooting
Table 5. Fisher EWNS Valve Troubleshooting
Problem Possible Solution
Packing leakage
Verify the correct packing torque or compression.
Disassemble and inspect packing box bore and valve stem for graphite
adhesion, excessive wear or scratches.
If needed, increase packing load to maximum per the Packing Adjustment
section of this manual. Replace packing parts and inspect packing box and
shaft at next available maintenance interval.
Body to Bonnet Leakage
Verify proper torque on bonnet studs and nuts.
Disassemble and inspect sealing surfaces on the bonnet and valve body for
scratches or nicks. Replace gaskets.
Valve Won't Stroke
Verify the correct packing torque or compression is not too high.
Disassemble valve body, inspect cage bore and plug for damage and debris.
Inspect plug and seat ring for indications of plug sticking in seat ring.
Replace damaged parts as needed. Replace gaskets.
Inspect actuator, refer to actuator instruction manual
Other Contact your Emerson sales office if more assistance is needed.

Instruction Manual
D103551X012
EWNS Valve
March 2022
18
Figure 9. NPS 20x16 and NPS 22x16 EWNS Valve
GE52555-B
APPLY LUB

Instruction Manual
D103551X012
EWNS Valve
March 2022
19
Figure 10. EWNS Valve Configuration
NPS 20X16 AND 22X16 EWNS BIDIRECTIONAL ANTI-EXTRUSION SEAL TRIM

Instruction Manual
D103551X012
EWNS Valve
March 2022
20
Parts Ordering
Each body‐bonnet assembly is assigned a serial number, which can be found on the valve body. This same number also
appears on the actuator nameplate when the valve body is shipped from the factory as part of a control valve
assembly. Refer to the number when contacting your Emerson sales office for technical assistance or when ordering
replacement parts.
When ordering replacement parts, be sure to include the 11‐character part number for each part required from the
following parts list.
WARNING
Use only genuine Fisher replacement parts. Components that are not supplied by Emerson should not, under any
circumstances, be used in any Fisher valve, because they may void your warranty, might adversely affect the performance
of the valve, and could cause personal injury and property damage.
Parts List
Note
Part numbers are shown for recommended spares only. Contact your
Emerson sales office for Part Ordering information.
Key Description Part Number
1 Valve Body ‐‐‐
2* Cage See following table
3* Seat Ring See following table
4* Plug/Stem Assy See following table
5* Spiral Wound Gasket See following table
7 Body-Bonnet Stud See following table
8 Body-Bonnet Nut See following table
9 Packing Flange See following table
10 Bonnet ‐‐‐
11* Packing Box Ring See following table
12* Guide Bushing See following table
13* Packing Ring See following table
Key Description Part Number
14 Packing Nut See following table
15 Packing Stud See following table
16* Packing Ring See following table
17 Packing Follower See following table
18 Washer (Packing Stud) See following table
19 Indicator See following table
20 Belleville Spring See following table
21 Machine Screw (Load Scale) See following table
22 Load Scale See following table
24 Washer (Body-Bonnet Stud) See following table
27 Nuclear Grade anti-seize lubricant
28* Set Screw See following table
29* Backup Ring (plug) See following table
30* Anti-extrusion Ring (plug) See following table
31* Spring Loaded Seal Ring (plug) See following table
32* Spacer Ring (plug) See following table
33* Retainer Ring (plug) See following table
34* Packing Washer See following table
35* Anti-extrusion Ring (seat ring) See following table
36* Spring Loaded Seal Ring (seat ring) See following table
37* Spacer Ring (seat ring) See following table
38* Backup Ring (seat ring) See following table
39* Retainer Ring (seat ring) See following table
202 Machine Screw
203 Nuclear Name Tag
204 Serial Tag
205 Flow Arrow
*Recommended spare parts