Fisher Manuals & Guides: Fisher CVX Blowout Fixture Manuals & Guides

Instruction Manual

D103629X012

Fisherr CVX Blowout Fixture

Contents

Introduction 1.................................

Scope of Manual 1.............................

Description 1.................................

Educational Services 2.........................

Principle of Operation 2.........................

Maintenance 2.................................

Valve Disassembly 3...........................

Actuator Removal 3........................

Packing Box 3.............................

Bonnet and Trim 3.........................

Visual Inspection 4.........................

Installation of the Blowout Fixture 5..............

Piping Blowdown with the Blowout Fixture

Disassembly of the Blowout Fixture 6.............

Reassembly 6.................................

Ordering Information for Flanged Fixture 7.........

Blow Fixture Design Conditions 7................

Ordering Information for BWE Fixture 7............

Blow Fixture Design Conditions 7................

CVX Blowout Fixture

October 2012

Installed 5.................................

Cleaning 6................................

Introduction

Scope of Manual

This instruction manual includes installation and operation information for the Fisher CVX Blowout Fixture. Piping
blowdown is very important to successful plant startup and trouble free operation. The plan for piping blowdown
should be undertaken by professionals familiar with all aspects of blowdown operation. This manual is not intended to
cover all details required for successful piping system cleaning.

CVX valves are available with either integral welded diffusers or bolted removable diffusers. Some instructions are
different between both constructions. See table 1 or consult your Emerson Process Management sales office to
determine which blowout fixtures are available for use.

Key numbers identified for valve disassembly are shown in the specific valve instruction manual. Refer to separate
instruction manuals for instructions covering the exact valve, actuator, and accessories associated with the blowout
fixture.

Do not install, operate, or maintain a CVX Blowout Fixture 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 Process Management sales office before
proceeding.

Description

The CVX Blowout Fixture provides a convenient way to clean piping upstream of the valve while taking care not to
damage internal valve parts.

www.Fisher.com

CVX Blowout Fixture

October 2012

Instruction Manual

D103629X012

Educational Services

For information on available courses for the Fisher CVX Blowout Fixture, as well as a variety of other products, contact:

Emerson Process Management
Educational Services, Registration
P.O. Box 190; 301 S. 1
Marshalltown, IA 50158-2823
Phone: [phone] or
Phone: [phone]
FAX: [phone]
e-mail: [e-mail]

Table 1. Fisher CVX Blowout Fixture Availability

CVX welded seat ring &

welded integral diffuser

CVXboltedseatring&

welded integral diffuser

CVXboltedseatring&

bolted removable diffuser

st

Ave.

Flanged Outlet - Bonnet

Blowout

NA Available NA Available

NA Available NA Available

Available Available Available Available

Flange Inlet - Bonnet

Blowout

BWE Outlet - Bonnet

Blowout

BWE Inlet - Bonnet

Blowout

Principle of Operation

TheBlowoutFixturereplacesthevalvecageandplug,aswellasthevalvebonnet.Thefixtureallowssteamflowfrom
the inlet or outlet piping to be directed through the valve, out the blowout fixture, and through temporary piping.

Maintenance

WARNING

To avoid personal injury or property damage from the release of pressurized process media, ensure that the system is
completely depressurized and appropriate safety measures have been taken prior to carrying out any of the following
procedures. Only trained competent individuals with the proper equipment should attempt to disassemble and install a
Blowout Fixture, and reassemble a CVX valve.

D Do not remove the actuator from the desuperheater 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, 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.

2

Instruction Manual

D103629X012

CVX Blowout Fixture

October 2012

Valve Disassembly

The following valve disassembly steps are intended as a quick reference only. Refer to the CVX instruction manual,
D103606X012, for key numbers and further detail regarding valve disassembly.

Actuator Remov al

The following actuator disassembly steps are intended as a quick reference only. Refer to the appropriate actuator
instruction manual for further detail regarding actuator removal.

1. Release the actuator seat load by either manually stroking the valve or applying the appropriate instrument signal.

Thestemconnectormayberemovedoncetheplugisoffofthevalveseat.

2. If an instrument signal has been used to stroke the plug off the seat, remove the signal only after removing the

stem connector.

3. Isolate and disconnect the operating lines from the actuator.

4. Loosen the yoke fasteners, as appropriate, and remove the actuator from the valve.

Packing Box

Unbolt the packing stud nuts, (key 68), and remove the packing flange (key 66) and packing follower, (key 65)
(reference the appropriate instruction manual for key numbers). Remove as much packing as possible from the
packing box.

CAUTION

Extreme care should be taken to avoid scratching the stem or the packing box.

Bonnet and Trim

1. Loosen the bonnet stud nuts, (key 55) using an even and opposing pattern (for example, if the first nut loosened is

at the 1 o'clock position, the next nut to be loosened would be at the 7 o'clock position). This will prevent uneven
loading of the bonnet studs which may cause binding.

Individual nuts should not be completely loosened while the remaining nuts are tight. It is suggested that at least two
stages of loosening be used to avoid overloading the last few remaining studs.

2. Remove the bonnet (key 6) from the valve with uni-axial pull. If the bonnet seems to bind in the valve body, check

the alignment of the hoist or pulling mechanism. Deviation from an axial pull of the parts may result in galling or
bending of the stem (key 23).

CAUTION

Do not attempt to over-power any binding, as damage to the guide surfaces may result.

The bonnet may be lightly tapped back into alignment with a soft face mallet. The stem and plug should be pushed
back into the valve body while the bonnet is being removed. Once the bonnet is removed, dislodge any remaining
packing rings from the packing box.

3

CVX Blowout Fixture

October 2012

Instruction Manual

D103629X012

3. Remove the packing ring (key 63) from the bottom of the packing box. Lightly sand the inside of the packing box

with 60 or 80 grit paper to remove any adherent packing material. Final cleanup should be made with 160 grit or
higher paper.

4. Inspect the bonnet guiding surfaces and gasket mating surfaces. Light damage on the guiding surface may be

repaired with an emery cloth or other suitable material. Damage to the gasket mating surface may require bonnet
replacement to avoid leakage.

5. Remove the plug assembly (key 22, 23, and 53) as a single unit by grasping the valve stem (key 23) and pulling the

assembly from the body cavity. The plug assembly contains sensitive guiding and sealing surfaces on its outside
diameter and care must be taken in its handling. The plug should be temporarily stored on a clean wooden or cloth
surface.

6. Remove the cage (key 21) from the valve body. Remove and discard the upper and lower cage gaskets (key 43).

Reference the CVX valve instruction manual for guidance in performing this disassembly. The cage contains
sensitive guiding surfaces on its outside diameter and care must be taken during handling. The cage should be
temporarily stored on a clean wooden or cloth surface.

7. Clean and inspect the guiding and sealing surfaces of the plug assembly. For balanced plug designs, inspect the

piston ring (key 45) and Bore Seal ring (key 46) for signs of excess wear or damage and replace if necessary. The
piston ring is a two piece design with an outer seal ring and an inner expander ring. The outer ring diameter should
be expanded beyond the diameter of the plug in its free state. It can be shifted within its groove to inspect for
uneven wear around its circumference. The piston ring should require some compression when installing the plug
into the cage. Lack of required compression indicates that the piston ring has worn or relaxed and s hould be
replaced. Vertical marks in the axial orientation also indicates wear that requires replacement of the ring. The Bore
Seal ring has a C-shaped cross section with the open portion of the C-shape facing the stem side of the plug for
flow-updesignsandtheopenportionoftheCshape facing the seating surface of the plug for flowdown designs.
Any uneven marks around the circumference of the ring or any flattening of the ring shape at its outside diameter
are indications of wear and require replacement. Contact your Emerson Process Management sales office for Bore
Seal ring replacement.

8. Clean and inspect the inside diameter surfaces of the cage.Theentirelengthofthecageinside diameter is either a

sealing and/or guiding surface and any measurable wear requires that the cage be replaced.

9. Integral welded diffuser only: The seat ring remains retained inside the valve body regardless if it is bolted or

welded. Clean and inspect the angled seating surface. Anydetectabledamagearoundthecircumferenceofthe
seating surface is an indication of wear and requires reconditioning to ensure seating performance. Contact your
Emerson Process Management sales office for specific instructions on reconditioning the seating surface.

10. Removable bolted diffuser only: The bolted seat ring and removable diffuser must be removed. Loosen the seat

ring bolts, (key 76) using an even and opposing pattern (for example, if the first nut loosened is at the 1 o'clock
position, the next nut to be loosened would be at the 7 o'clock position). This will prevent uneven loading of the
seat ring studs, which may cause binding. Individual bolts should not be completely loosened while the remaining
bolts are tight. It is suggested that at least two stages of loosening be used to avoid overloading the last few
remaining studs. Reference the CVX instruction manual for guiding on removing the bolted seat ring and
removable diffuser (key 77). Discard lower cage gaskets (key 75). The bolted seat ring and removable diffuser
contain sensitive guiding and gasket surfaces on its outside diameter and care must be taken in their handling. The
seat ring and removable diffuser should be temporarily stored on a clean wooden or cloth surface.

11. Remove all used gaskets and foreign matter from the interior of the valve and from the inlet and outlet openings.

Removeanyforeignmatterthatmaybeinthevalvebodyortrim.Inspectallvalvebodyguidingandsealing
surfaces for any signs of wear.

Visual Inspection

Visually inspect the interior of the valve for abnormal wear, signs of erosion, or scoring if the valve has been in service.
All scores and scratches should be removed by grinding or filing to remove any interference of the clearance zones
between the internal bores and the mating parts. The affected area should be sanded with 100 grit or finer paper. Do
not attempt to completely remove the score, only the interference should be removed and sanded.

Thegasketsurfacesofthevalvebodyandbonnetshouldbeinspected to verify that they are not damaged and are free
of imbedded gasket material.

4