4
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strainer (wire mesh filter) installed before the valve increases certainty of its correct action,
-
the responsibility for correct selection of the valve to the operating conditions, distribution and installation is borne
by system designer, contractor and user.
The ball valves are designed for applications independent of external conditions.
Where there is a risk of erosion caused by external conditions (weather, aggressive vapors, gases, etc.), we recommend a special
corrosion protection or the use of specially designed ball valves after discussion with the manufacturer.
7. MAINTENANCE
During maintenance following rules should be observed:
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startup process – sudden changes of pressure and temperature should be avoided when starting the plant,
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valve is closed by turning the hand lever clockwise looking down on the hand lever. Hand lever position parallel to valve
axis indicates that valve is open. Shut off is done by turning hand lever 90º. When changing hand lever position from open
into close and inversely remember that turn limiters have established strength which should be not exceeded .
-
valve is open by turning the hand lever counter-clockwise,
-
performance of fitted valves can be checked by multiple closing and opening
-
if during valve operation heat parts of the valve, for example hand lever or body could cause burn, user is obliged to protect
them against touch
maximum working temperature of ball valve must be not exceeded, in the other case stem leakage could appear soon
and it would be necessary to shut down the valve and replace the sealings.
In order to assure safety performance, each valve (especially rarely used) should be surveyed on regular basis.
-
if the ball valve provided with actuator was assembled, operating manual of actuator (attached to the actuator) should be
obeyed during operation,
- in the case of break of actuator power supply, emergency valve control by actuator handwheel is possible,
- during pipeline painting actuator components should be protected.
8.
SERVICE AND REPAIR
All service and repair jobs should be carried out by authorized staff using suitable tools and original spare parts. Before disassembly
of complete valve from the pipeline or before service, the pipeline should be out of operation. During service and repair jobs it is
necessary to:
-
decrease pressure to 0 bars, valve temperature to ambient temperature,
-
use personal health protectives in pursuance of existing threat,
valve open
shut off
valve closed
open
