Management of Change Guide
Replacement of Fisher™ 657 Diaphragm
Actuators Sizes 30-70 with Sizes 30i-70i
Table of Contents
Management of Change ..................................2
Background ....................................................2
Question & Answer Checklist ..........................2
September 2018
D352339X012
Comparison of 657 and 657 Size i Actuators ....4
Scope of Sizes ..................................................................... 4
Instrument Attributes ........................................................ 5
Side-Mounted Handwheel .................................................. 6
Other Instrument and Accessory Mounting ........................ 6
Approximate Actuator Weights .......................................... 6
Conclusion ......................................................7
Additional Resources ......................................8
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 efciency. 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 657 spring-opposed diaphragm actuator positions the valve plug in
response to varying controller or valve positioner pneumatic output signals applied to
the actuator diaphragm. The 657 actuator is direct-acting. This actuator is designed
to provide dependable on/off or throttling operation of automatic control valves.
The 657 size i spring-opposed diaphragm actuator provides an updated yoke
design to increase reliability and reduce complexity by incorporating an integrated
mounting for Fisher FIELDVUE™ instruments.
MOC: 657 Actuators Size 30i-70i
September 2018
D352339X012
Question & Answer Checklist
Q: Does the proposed modication cause any changes to the piping and
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instrumentation diagram (P&ID)?
A: No.
Q: Does the proposed modication change process chemistry,
technology, or operating and control philosophies?
A: No.
Q: Does the proposed modication change how the existing plant is
operated?
A: No.
Q: Does the proposed modication change process ows?
A: No.
Q: Does the proposed modication change existing pressure relief cases?
A: No.
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Q: Does the proposed modication change the process description?
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A: No.
Q: Have the codes and standards to which the new equipment was
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designed changed?
A: No. However, they may have been updated since Fisher 657 actuators
were installed.
Q: Does the proposed modication change the materials of construction,
such as a change in material form (cast, forged, or alloy)?
A: No.
Q: Does the proposed modication introduce new equipment items that
require periodic predictive maintenance?
A: No. These equipment items will require the same periodic predictive
maintenance.
MOC: 657 Actuators Size 30i-70i
September 2018
D352339X012
Q: Does the proposed modication change existing operator training
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requirements?
A: No.
Q: Does the proposed modication introduce new equipment items
that require spare parts, training manuals, maintenance procedures
or training to teach the maintenance department how to maintain
them?
A: Yes. Emerson sales ofces offer local training and support to help
ensure operators, maintenance personnel, and instrument technicians
are trained on Fisher 657 size i actuators.
Q: Does the proposed modication introduce new equipment items that
require spares or obsolete spares for existing equipment?
A: No. Existing spares for 657 sizes 30 through 70 actuators are
compatible with 657 sizes 30i through 70i actuators.
Q: Does the proposed modication permanently remove the spares for
existing pieces of equipment?
A: No.
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