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Management of Change Guide: Replacement of A-Body Valves with Vee-Ball Valves in Hydrofluoric Acid Service
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Fisher Management of Change Guide: Replacement of A-Body Valves with Vee-Ball Valves in Hydrofluoric Acid Service Manuals & Guides

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Management of Change Guide
D352048X012 / September 2018
Management of Change Guide for Replacement of Fisher™ A-Body Valves in
Hydrouoric Acid Service
Table of Contents
Fisher A-body, Masoneilan 10000, and Fisher
Face-to-Face Dimensions .................................................... 5
Capacity ............................................................................. 5
Weight ............................................................................... 6
Environmental Compliance ................................................. 6
Suitability for Hydrouoric Acid Service .............................. 6
MOC: Replacing A-Body Valves in Hydrouoric Acid Service
Management of Change
Management of Change (MOC) is a procedure used to proactively manage changes that have the potential to impact safety or the process within a plant. Evaluating new techniques for improving MOC approval procedures can have an impact on
plant efciency. Historically, upgrading obsolete products or replacing existing process control equipment had been delayed or abandoned due to the extensive paperwork involved in completing a complex MOC approval sheet.

Background

Historically, many Fisher A-body and other double-ported sliding-stem valves have been used in Hydrouoric Acid Alkylation (HF Alky) units. They were used both in the UOP and Phillips licenses, but saw more limited usage in UOP’s license due
to the use of a screwed-in seat ring. With UOP taking on full ownership of both
licenses, the A-body construction will see little use in new applications. Although the A-body has been a successful valve for these acidic applications, it is an inactive product, which results in challenges in constructing new valves, as well as maintaining existing constructions.
D352048X012 / September 2018
Emerson has partnered with UOP to determine a suitable replacement for A-body constructions in HF Alkylation units. This partnership led to the selection of the
Fisher easy-e™ valve (utilizing post-guided trim of the EZ valve) and the Fisher Vee­Ball™ control valve. The easy-e valve can be used for most applications up to NPS 4.
For valves NPS 6 and larger, it is desirable to use a Vee-Ball control valve solution. However, shifting from an A-body to a Vee-Ball valve is a signicant change in
control valve selection.
The purpose of this document is to simplify the transition from existing control valve A-body installations, which may be beyond their service life or no longer provide the control and reliability required, to the proven reliable Fisher Vee-Ball
control valve.
Contained in this document are two sections. First, there is a question and answer
section to help users complete Management of Change (MOC) approval documents
when modernizing to a Fisher Vee-Ball control valve. Then, there is a side-by-side comparison of the Fisher A-body, Masoneilan 10000 (also a double-ported sliding­stem valve) and the Fisher Vee-Ball control valves. These comparisons demonstrate how users can safely and efciently replace existing problematic or maintenance-
prone double-ported sliding-stem valves with the Fisher Vee-Ball control valve.

Question & Answer Checklist

Q: Does the proposed modication cause any changes to the piping and
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instrumentation diagram (P&ID)?
A: Possibly. If the valve size changes, concentric reducers to the control
valve inlet and outlet may need to be added to the P&ID.
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MOC: Replacing A-Body Valves in Hydrouoric Acid Service
Q: Does the proposed modication change process chemistry,
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3
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technology, or operating and control philosophies?
A: No.
Q: Does the proposed modication change how the existing plant is
operated?
A: No.
Q: Does the proposed modication change process ows?
A: No.
Q: Does the proposed modication change the process description?
A: No.
D352048X012 / September 2018
Q: Have the codes and standards to which the new equipment was
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designed changed?
A: No, although they may have been updated since the A-body was
installed.
Q: Have the operating and design conditions (ow, temperature,
pressure, process uids) of the proposed modication changed?
A: No.
Q: Does the proposed modication change the materials of construction
such as a change in material form (cast, forged) or alloy?
A: No.
Q: Does the proposed modication introduce new equipment items that
require periodic predictive maintenance?
A: No. The new equipment items will require the same periodic
maintenance as required by the old equipment items.
Q: Does the proposed modication change existing operator training
requirements?
A: Yes. The Emerson sales network offers local training and support to
ensure operators, maintenance personnel, and instrument technicians
are fully trained on the Fisher Vee-Ball control valve.
3
MOC: Replacing A-Body Valves in Hydrouoric Acid Service
Q: Does the proposed modication change existing pressure relief cases?
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A: Probably. If the replacement selection exceeds the maximum rated Cv
of the existing A-body, then pressure relief cases will require review.
Pressure relief valve sizing when sizing and selecting Fisher control valves for end-user applications is not considered. If the control valve
is determined to affect upstream or downstream safety relief cases,
review by the end user or third party is recommended.
Q: Does the proposed modication introduce new equipment items that
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require spare parts, training manuals, maintenance procedures, or
training to the maintenance department?
A: Yes. The new equipment requires spare parts, training manuals,
maintenance procedures, and training to the maintenance department that are specic to the new Fisher equipment items.
Q: Does the proposed modication permanently remove the spares for
existing pieces of equipment?
A: Yes. The spare parts of the existing equipment items should be
removed from the plant.
D352048X012 / September 2018
Q: Does the proposed modication require welding work to be
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performed?
A: If anged spacers or concentric reducers are allowed in the plant, no
welding work should be required. Face-to-face dimensions and valve size will most likely change.
Q: Does the proposed modication change the inspection scope or
inspection interval?
A: No.
Q: Have the materials of construction been reviewed to ensure that the
metallurgy is correct?
A: Yes.
4
MOC: Replacing A-Body Valves in Hydrouoric Acid Service

Fisher A-body, Masoneilan 10000, and Fisher Vee-Ball Control Valve Comparison

There are many physical differences between these control valve constructions. Due to the hazardous nature of hydrouoric acid, there are advantages in the design of
the Fisher Vee-Ball control valve for these acidic applications. Often when replacing
a Fisher A-body or Masoneilan 10000 with a Vee-Ball valve, a Vee-Ball—one to two sizes smaller—will be required based on control valve sizing. This results in even greater differences between the existing and proposed valve.

Face-to-Face Dimensions

The Fisher A-body, Masoneilan 10000, and Fisher Vee-Ball control valve all have
unique face-to-face dimensions.
D352048X012 / September 2018
Fisher A-Body Masoneilan 10000
NPS Inches
6 18.62 18.62 9.00
8 22.38 22.40 9.56
10 27.88 26.02 11.69
12 30.50 30.24 13.31
Table 1. Fisher A-body, Masoneilan 10000, and Fisher Vee-Ball CL300 RF Control Valve Comparison
The use of spool pieces or concentric reducers will likely be required if the customer
is not replacing piping during the modernization.
Fisher Vee-Ball
CL300 RF

Capacity

Due to the extreme differences in valve geometry and resulting sizing coefcients, each valve will need to be re-sized to use a Vee-Ball construction replacement. The table below provides examples of this. Control valve sizing shall be conducted using
current Fisher sizing software.
Fisher A-Body
Hi-Lift V-Port
NPS Cv
6 438 450 1100
8 765 750 1820
10 1320 1160 3000
12 1760 1620 3980
Masoneilan 10000 Fisher Vee-Ball
Table 2. Fisher A-body Hi-Lift V-Port, Masoneilan 10000, and Fisher Vee-Ball Control Valve Capacity Comparison
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MOC: Replacing A-Body Valves in Hydrouoric Acid Service
PACKING BOX STUD
ACTUATOR MOUNTING YOKE
VALVE SHAFT
YOKE BEARING
PACKING FLANGE
PACKING FOLLOWER
SPRINGS
VALVE BODY
ANTI­EXTRUSION RINGS
PACKING BOX RING
PTFE PACKING V-RINGS SHOWN
VALVE SHAFT
PACKING FLANGE
PACKING BOX RING
GRAPHITE PACKING SET
PACKING FOLLOWER
SPRINGS
SINGLE PTFE PACKING
GRAPHITE PACKING
W6125-1 / IL
W5806-1 / IL

Weight

Since it will likely be a smaller size, the Fisher Vee-Ball control valve will be signicantly lighter weight than an A-body or Masoneilan 10000 construction.
D352048X012 / September 2018
Figure 1. Typical ENVIRO-SEAL™ Packing Arrangements for Fisher Rotary Valves

Environmental Compliance

Many existing double-ported constructions may have packing selection that pre­dates low-emission packing technology. Historically, the Phillips license required a virgin stack of PTFE packing, while the UOP license required Chesterton Style 324
packing with a lubricator and isolator valve with polymer grease. Both of these packing styles are based on legacy process units that were constructed prior to the
availability of low emission packing options. For HF alkylation units today, UOP has reviewed the Fisher ENVIRO-SEAL™ packing system and agrees it is suitable for this service. Typically, ENVIRO-SEAL PTFE or ENVIRO-SEAL Graphite packing are options. In either packing style, all metal packing parts shall be N04400 or a material compatible with HF acid, including packing studs and nuts.
Suitability for Hydrouoric Acid Service
One of the main reasons for limiting the double ported design in the UOP licensed
HF Acid Alkylation unit was due to the screwed-in seat ring. This feature is inherent to both the Fisher A-Body and Masoneilan 10000 valves. There are two reasons this seat ring is undesirable for HF Acid service:
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MOC: Replacing A-Body Valves in Hydrouoric Acid Service
Employee Safety
To enter an HF Acid unit, head to toe personal protective equipment (PPE) is
required. It is desired that any potential trapped HF vapors be released while
personnel is wearing their PPE. However, the screwed in seat ring cannot be removed until complete valve disassembly takes place—usually this is in an on-site maintenance shop or in an off-site valve service center. Although a
user will do as much as possible to remove all trace amounts of HF acid from
these valves, there is still a potential for vapors to be trapped between the valve body and the screwed in seat ring. See Figure 2.
Vibration
Some HF units experience high vibration for a variety of reasons. In these cases, the screwed in seat ring has been known to back out of the valve body. This can prevent the valve from closing and cause process upsets.
Both of these risks can be avoided by welding (tack weld or seal weld) in the
seat ring in the double ported valve, however, the materials that the trim parts are made from in these valves can require difcult weld procedures.
Users may have limited documentation on whether the seat ring has been
welded into the valve body, which makes duplication of existing units more
challenging.
D352048X012 / September 2018
The Fisher Vee-Ball valve body assembly and materials of construction have been reviewed part-by-part for suitability in HF Acid service. The diagram and parts list on the following page conrm selection for this application.
Screwed-in seat ring. Any
weld modications shall be performed by certied
Fisher service center or manufacturing facility.
Fiure 2. Screwed-in Seat Ring on an A-Body Valve
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MOC: Replacing A-Body Valves in Hydrouoric Acid Service
D352048X012 / September 2018
Key No.
1
2
3
4
5
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Part Description Material
WCC per FMS20B113
Valve Body
Ball M35-1
Seat Protector Ring M35-1
Taper Key N05500
Drive Shaft N05500
Groove Pin N04400
Follower Shaft N05500
Bearing N04400/PTFE
Ball Seal TCM Plus
or SA516 Grade 70 per
FMS20B106
(5)
(1)(2)
(5)
or M35-1
Key No.
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24
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Part Description Material
Packing Set
Packing Follower N04400
Packing Follower Stud N04400
Packing Follower Nut N04400
Seal Protector Screw N04400
Seal Protector Clip N04400
Actuator Mtg Screw B7M
Actuator Mtg Nut 2HM
Pipe Plug
(1) (3)
(4)
N04400 for WCC Body;
Consult factory for M35-1
Body
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1. All wetted internal parts to be constructed of Nickel-Copper Alloys (M35-1, M35-2, N04400, or N05500).
2. When replacing Fisher A-Body constructions, review sizing and design conditions. Capacity, shut-off classication, and dimensions (both face-to-face and overall envelope) will change.
Spool pieces or concentric reducers may be required to maintain the take out dimensions of the A-Body being replaced if new piping will not be installed.
3. Historically, UOP specied Chesterton Style 324 packing with lubricator and isolator valve with polymer grease or manufacturer’s recommendation for Hydrouoric Acid. The Phillips license
allowed a stack of virgin PTFE rings, and often also included the lubricator and isolator valve. However, both of these packing selections are based on legacy units that were constructed prior to the availability of low emission packing options. In both new and existing HF Alkylation units, ENVIRO-SEAL PTFE and Graphite packing are options with N04400 packing parts, with customer
approval. Neither the Phillips or UOP specications address ENVIRO-SEAL designs, since availability to the market occurred after the specications were written. UOP has reviewed the Fisher
ENVIRO-SEAL packing system and agrees it is suitable for this service.
4. Internal metal components of the packing system shall be N04400 or a material suitable for Hydrouoric Acid. The packing box ange, studs, and nuts shall be N04400. Standard Belleville Springs in N07718 can be utilized. Provide one extra set of packing, two extra sets of body gaskets, and two extra sets of ange gaskets for shipment with this valve.
5. Valve body end tapping should be included in HF Alkylation Vee-Ball constructions. This option is added to reduce operator exposure to Hydrouoric Acid vapor by allowing a means of removing
the trapped gas before the valve enters a maintenance shop or service center.
Gasket Graphite Laminate
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Packing Box Ring Factory for M35-1 Body
Table 3. Fisher V150/V300 Vee-Ball Valves for HF Acid Service
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on dark backgroundson light backgrounds
standard
no gradients
watermark
stacked logo (for sharing only)
standard
no gradients
watermark
stacked logo (for sharing only)
MOC: Replacing A-Body Valves in Hydrouoric Acid Service

Conclusion

Reliable Fisher control valves have been used in the process control industry for over 130 years. With a modern and efcient design, the Fisher Vee-Ball control valve
offers multiple advantages that allow a user to transition from a legacy double-
ported sliding-stem valve. This document should help speed up the MOC process.
Both end users and the sales ofce should exercise extreme care when specifying or entering an order for rotary valves to ensure proper material specications throughout the entire bill of material. Rotary valves should be utilized only when specied and should not be substituted for globe valve specications without approval by end user. An oversized actuator (1.5x required thrust) may also be
considered to overcome any inevitable build-up.
Some end users have specied no rotary products in HF Acid service. Be sure specications are reviewed before offering this solution.

Additional Resources

Brochure: Fisher Vee-Ball Control Valves
D352048X012 / September 2018
http://www.Facebook.com/FisherValves
http://www.Twitter.com/FisherValves
Emerson Automation Solutions
Marshalltown, Iowa 50158 USA Sorocaba, 18087 Brazil Cernay, 68700 France Dubai, United Arab Emirates Singapore 128461 Singapore
http://www.YouTube.com/user/FisherControlValve
http://www.LinkedIn.com/groups/Fisher-3941826
© 2018 Fisher Controls International LLC. All rights reserved.
Fisher, Vee-Ball, and ENVIRO-SEAL are marks owned by one of the companies in the Emerson Automation Solutions business unit of Emerson Electric Co. Emerson and the Emerson logo are trademarks and service marks of Emerson Electric Co. All other marks are the property of their respective owners.
The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, nothing herein is to be construed as a warranty or guarantee, express or implied, regarding the products or services described herein or their use, performance, merchantability or tness for a particular purpose. Individual results may vary. All sales are governed by our terms and conditions, which are available upon request. We reserve
the right to modify or improve the designs or specications of our products at any time without
notice. Responsibility for proper selection, use and maintenance of any product or service remains solely with the purchaser and end user.
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