Maintenance; Change Of The Spindle Packing - Circor MV 5000 Serie Einbau- Und Betriebsanleitung

Einbau- und Betriebsanleitung
Installation and Operating Instructions
Instructions de montage et de service
Strenuous tightening will cause high friction, which aggravates the movement of spindle and therefore may impair
the functioning of the control valve.
Flange connections bolts should never be loosened or tightened when the valve is under temperature and pressure,
even when trying to eliminate a leakage problem.
• Size Check – Control Valve
The control valve should operate at approximately 70 to 100% of the stroke in normal operating conditions.
Max. Flow rate not reached:
Check whether the valve is 100% open
Check whether all manual shut-off valves are opened and strainers are cleaned.
Check the valve sizing data with respect to the actual operating data
Valve operating with small stroke:
To prevent premature wear of valve the design of valve should be adopted to the actual operating data. Measures
should be discussed with manufacturer.
• Checking of the control
it is essential that the scheme be checked for stability. Ideally, the control valve should stop after reaching the setpoint.
Unstable control (constantly stepping back and forth) will lead to premature wear. In this case, please contact the
manufacturer.
When operating electric actuators, a pause of at least 200 ms should be observed between the control steps when
changing direction. The minimum step duration should not be less than 50 ms.
To prevent premature wear of the control valve, oscillation at the point of closure must be avoided.
5

Maintenance

5.1

Change of the spindle packing

In general, damaged stem seals must be replaced or retightened immediately (for pure graphite packings), otherwise a new packing
may leak again within a short period of time.
The design of the stem seals is described in the respective technical data sheet. Spindle seals can be obtained as a spare parts
set from the manufacturer. Please always indicate the "W. No." of the valve when ordering. This can be found on the type plate
which is attached to the cross member plate.
• Depressurize the valve and drain the pipelines according to the regulations
• To replace the stem seal, the actuator must be removed. The mounting and dismounting of the actuator is described in
the operation instructions of the respective actuator.
• Loosen and remove the union nut.
• Remove the old packing (packing puller) and clean the packing chamber.
• Clean the valve stem
• Insert new packing, stuffing box and spring according to the enclosed sectional drawing.
• Fasten union nut
For packing graphite strenuous tightening will cause high friction, which aggravates the movement of spindle.
6150-8010
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10/2020