Fisher Control-Disk Instruction Manual page 5

Instruction Manual
D103298X012
sizes. If piping with a smaller inner diameter than specified above is connected to the valve, measure carefully to be certain
the disk rotates without interference before putting the valve into operation.
5. Flow is in the standard direction when the seal retainer (key 2) is facing upstream. Standard flow direction is also
indicated by the flow direction arrow cast into the valve body. Flow in the reverse direction is permissible within
allowable pressure drop limits for the soft seal. The metal seal is forward flow only.
CAUTION
Control‐Disk valve disk rotation is counterclockwise to open (when viewed from the actuator side of the valve body, see
figure 7) through 90 degrees of disk rotation. Rotating the disk (key 3) past either the open or closed position could
damage the seal and disk sealing surfaces and could cause the disk to jam in the seal retainer.
6. With the disk in the closed position, install line flange gaskets, and insert the valve between the pipeline flanges.
Use either flat sheet gaskets or spiral‐wound gaskets with compression‐controlling centering rings. Spiral‐wound
gaskets without compression‐controlling centering rings are not recommended for this purpose.
7. Depending on valve size and pressure rating, the wafer style valve is centered in the pipeline using either retainer
clips or the flange bolt holes. (For valves that have four flange bolt holes in the valve body (key 1), each hole
engages one corresponding line flange stud.) Insert the valve between the flanges and use either the retainer clips
or install two or more line flange studs into the line flanges to help hold the valve in position while centering the
valve. Carefully center the valve on the flanges to ensure disk clearance.
D Select and install two pipeline gaskets.
Note
Lubricate line flange studs before inserting them into flanges. If necessary, provide additional support for the control valve
assembly because of its combined weight.
WARNING
For lugged valve bodies with threaded line bolt holes, personal injury and property damage could result from sudden
release of process pressure if line bolts are not properly installed. To ensure proper line bolt thread engagement, line studs
must be centered in the threaded section of the valve body so that each stud has equal thread engagement in the body. See
figure 2.
8. After centering the valve body, first lubricate and then install the remaining line flange bolting to secure the valve in
the pipeline. Tighten the nuts to the line flange studs in a crisscross pattern to ensure proper alignment of valve,
gaskets, and flanges.
WARNING
A Control‐Disk valve body is not necessarily grounded when installed in a pipeline. If the valve is used in a flammable or
hazardous atmosphere or for oxygen service, an explosion could result due to a discharge of static electricity from the valve
components. To avoid personal injury or property damage, always make sure the valve body is grounded to the pipeline
before putting the control valve assembly into operation in a flammable or hazardous atmosphere.
Control-Disk Valve
June 2017
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