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Keystone Figure 56 ButterFly valves
InstallatIon and MaIntenance InstructIons
2.4 Valve verification
Check the operation of the valve by operating
it to 'full open' and 'full close'. to verify the
valve operation, the disc position indicator on
the actuator or the manual operator should
rotate between the 'full open' and 'full close'
indicators. generally the valve disc travels
clockwise to close.
2.5 sources of possible danger
this section contains some examples of
possible foreseen danger sources.
2.5.1 Mechanical
a. When manual operators are used, available
space should be checked in order to avoid
hands being clamped.
B. Mechanical sparks caused on impact of
valve and e.g. tooling, are a potential source
of ignition of surrounding atmosphere.
2.5.2 Electrical
if static charges or stray electrical currents
can initiate explosions, the valve should be
grounded to earth.
2.5.3 Thermal
a. if the valve is used in applications with a
fluid temperature above 40°C the outside
of the body might be hot. sufficient
measurements should be taken to avoid
burning. a manual operated valve should be
opened and closed with sufficient protection
for the personnel operating the valve. For
example: protecting gloves.
B. Hot surfaces can be a potential source of
ignition of the environment.
2.5.4 Operational
Closing a valve too fast may result in
waterhammer in the upstream part of the pipeline.
Waterhammer results in excessive stresses in the
valve's body and will cause severe damage.
Waterhammer should be avoided in all
circumstances.
Due to differential pressure across the valve
disc, butterfly valves have the tendency to
be closed by the flow. this is called dynamic
torque. take care when unlatching or removing
the valve operating mechanism. the valve
might be closed by the dynamic torque created
by the flow.
2.6 troubleshooting guide
symptom
Possible cause
valve would not
1. actuator has failed
rotate
2. valve packed with debris
valve leaking
1. valve not fully closed
2. Debris trapped in valve
3. seat leakage
4. seat is damaged
Jerky operation
1. Debris trapped in valve
2. air supply actuator inadequate 2. increase air supply pressure and/or volume
3 maintenanCe
the Keystone butterfly valve figure 56 is
designed to require a minimum of maintenance.
Warning
Depressurize and, if necessary in case of
dangerous fluids, drain the line and flush with
appropriate cleaning fluid before starting any
maintenance. Failure to do so may cause serious
personal injury and/or equipment damage.
Before disassembling the valve ensure the valve
has been decontaminated correctly from any
harmful gasses or liquids and that it is within a
safe temperature range for handling.
Personnel making any adjustments to the valves
should utilize suitable equipment. All required
personal protection means should be worn.
Only personnel trained in all aspects of manual
and mechanical handling techniques must carry
out handling of all valves.
3.1 routine maintenance
routine maintenance or lubrication is not
required other than periodic inspection to
ensure satisfactory operation and sealing. if
problems occur with valve pressure tightness
the seat can be adjusted or replaced.
resolution
1. replace or repair
2. Flush or clean valve to remove debris
1. Close valve
2. Cycle and flush (with valve open) to remove debris
3. re-adjust seat
4. if possible rework seat and re-adjust
1. Cycle and flush (with valve open) to remove debris
3
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