3
notes
• the valve can be installed in the pipe-line either
with or without the actuator mounted on top of the
valve. Make sure that you can turn the disc cautious
so you can detect a mismatch resulting from a disc
touching the adjacent piping.
• Do not use the valve as a support of the pipe line
construction.
• adjacent piping must be positioned so that minimal
piping stresses are transmitted to the valve flanges
during or after installation.
• Handling and lifting of the valves during installation
Must be performed following the same instructions
described in previous paragraph ‘1.3 Handling’.
1. Check whether the flange distance meets
the valve face-to-face dimensions. spread
with adequate tooling the flanges for easy
insertion of the valve.
2. Close the valve so far, that the disc edge is
at least 10 mm within the body.
3. Insert the valve between the flanges, center
the valve body and insert all flange bolts.
4. Maintain the valve flange alignment while
gradually removing the flange-spreaders
and tighten the flange-bolts hand tight.
5. slowly open and close the valve to check
for adequate disc clearance.
6. Cross-tighten all bolting to the proper torque.
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.
Keystone
Butterfly valves Paraseal
InstallatIon and maIntenance InstructIons
imPortant
Mating flange faces should be in good condition
and free of dirt and/or inclusions. Both pipe
insides to be well cleaned.
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 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.
2.5 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.
