Fisher Manual: Replacement of Fisher POSI-SEAL A81 High-Performance Butterfly Valve with Fisher 8580 High-Performance Butterfly Valve Manuals & Guides

Management of Change Guide

September 2018

D352361X012

Replacement of Fisher™ POSI-SEAL™ A81

High-Performance Buttery Valve with Fisher
8580 High-Performance Buttery Valves

Table of Contents

Management of Change ..................................2

Background ....................................................2

Question & Answer Checklist ..........................2

A81 Valve and 8580 Valve Comparison ...........4

Scope, Size, Class ................................................................ 4

Capacities (Cv) .................................................................... 4

Actuator Sizing (Torque) ..................................................... 4

Dimensions ........................................................................ 4

Body Style .......................................................................... 4

Spare Parts ......................................................................... 5

Conclusion ......................................................5

Additional Resources ......................................5

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

The Fisher POSI-SEAL™ A81 rotary valve is a high-performance buttery valve

(HPBV) for use in automated on-off, quarter-turn applications. The A81 valve is
congured with a square shaft and mounting brackets meeting ISO5211 for use

with actuators such as rack-and-pinion style or similar. Fisher POSI-SEAL A81

valves are obsolete, effective October 2015, and have transitioned to the Fisher
8580 rotary valve.

MOC: POSI-SEAL A81 to 8580 Valve

September 2018

D352361X012

The Fisher POSI-SEAL A81 valve was developed together with and is very

similar to the Fisher 8580 rotary valve. The 8580 valve is typically congured
with a spline shaft and mated with Fisher 2052 or 1061 actuators for excellent
throttling performance. However, the 8580 valve is now available with shaft
style and actuator mounting options that make it possible to congure an 8580
valve identically as an A81 valve. Fisher 8580 valves congured with the square
shaft and ISO5211 mounting options will perform and install the same as the A81
valve and may be used in the same applications.

For more information regarding Fisher rotary valves, please contact your local

Emerson sales ofce.

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: No.

Q: Does the proposed modication change process chemistry,

technology, or operating and control philosophies?

A: No.

Q: Does the proposed modication change how the existing plant is

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operated?

A: No.

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