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Beschikbare talen
Beschikbare talen
C1
Safety warnings at service and maintenance
• At operation, the function of the valve shall be in compliance with the <Valve Destination>, see
section A2.
• The service conditions of the valve shall be in compliance with the valve markings, see section A4.
• Service and maintenance shall be performed by qualified personal. Qualified are those persons who,
due to experience, can judge the risk and execute the work correctly and who are able to detect and
to eliminate possible risks.
• At service the valve shall be inspected regularly for leakage or other effects that could affect the
safety for the personnel. The interval for these inspections depends on operating data, see C3
• If a fault or problem is detected at an inspection or manoeuvre test, the knife gate valve must be
maintained as soon as possible
• Valves, destined for use in an ATEX classified zone, must be marked according to the ATEX directive.
• At any start up, the stuffing box shall be visually inspected for leakage. If any leakage is detected, the
nuts on the gland shall be retightened according to table in section B7. Except for this action, no
maintenance is allowed on the valve when the pipe line is pressurised.
• At maintenance or repair of an actuator, it shall be disconnected as described in section B8. The pipe
section must be free from pressure and completely drained at both sides of the valve before any
maintenance begins.
• Some valve types can be installed as end valves. Contact Stafsjö for specific requirements and further
information.
• The temperature of the exterior parts of the valve depends of the fluid temperature inside – any
protective insulation is in the responsibility of the user.
• When the SLV and SLF valve body are closed by bottom cover and/or when SLH and SLX purge ports
are closed by plugs, flushing is recommended through the purge ports at service if it is not clean fluid.
1. The stuffing box packing together with the gland makes sure that no media reaches surrounding
environment where the gate exit the valve body. When the stuffing box packing (braids) shall be
changed, the gland bolts must be loosened, and the the pipe section shall be depressurised and
empty.
2. A valve with an actuator shall be actuated only if:
• The valve is installed between flanges or between a flange and a protective device.
• The gate guards are installed on the beams, on automatic operated valves.
Danger
3. If you install the knife gate valve as an end valve in a pipeline, always install protective equipment to
prevent people getting to close to the valve and being exposed to the media transported in the
system when the valve opens.
People's life and health is at stake if this is not observed. Any other action is the responsibility of the user.
C2
Manual and automatic actuation
A knife gate valve with handwheel closes clockwise as standard. Exceptions may occur based on customer requests.
A valve with automatic actuator is operated following the signals from the plant control system. Valves equipped with
actuator supplied by Stafsjö are exactly adjusted to stop in the exact end positions. This adjustment shall not be
changed as long as the valve operates correctly.
Valves with infrequent operation:
Stafsjö recommends a full operation test (open and close) at least twice a year (six months frequency) at normal
operating conditions. For severe services and/or specific application more frequent test intervals may be needed. It is
at the user's responsibility to evaluate which interval is suitable for their application/ process.
Document: is-VALVE, 22-10-01 issue: 16
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