KSB ECOLINE GT 40, Руководство по эксплуатации

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4 Valve Description
15 of 38
ECOLINE GT 40
7367.8/06-EN
4.5.2 Self-locking function
As standard, the trapezoidal stem thread is self-locking. For special designs, e.g.
multiple threads, the self-locking function is taken over by the actuator assembly.
The self-locking effect may be reduced over time due to wear.
4.5.3 Uncontrolled movements
In the following cases, the valve disc's position may change in an uncontrolled
manner due to the system's pressure with resultant effects on the plant:
▪ Control failure
▪ Signal error
▪
Power supply failure during operation
▪ Incorrect actuator setting
▪ De-activation of the position switches in the actuator
4.6 Function
Design The gate valve consists of the pressure-retaining parts, i.e. body 100 and yoke 166,
the functional unit (stem 200 and flexible wedge 361), and the actuating element.
Sealing Body 100 and yoke 166 are joined by studs 902.1 and hexagon nuts 920.1, and the
joint is sealed off by a joint ring 411.
The functional unit mainly consists of flexible wedge 361, stem 200 and the actuating
element, i.e. handwheel 961 or actuator.
The seating faces of body 100 and of flexible wedge 361 are hard-faced. Gland
packing 461, which seals off stem 200, is tightened via gland follower 452 by means
of eyebolts 900 and hexagon nuts 920.2.
4.7 Scope of supply
The following items are included in the scope of supply:
▪ Valve
▪
Valve operating manual
4.8 Noise characteristic
When operated within the operating conditions documented in the order
confirmation and/or characteristic curves booklets, the valve will not exceed a sound
pressure level of 80 dB in acc. with IEC 60534-8-4. Unfavourable piping layouts or off-
design operating conditions may give rise to physical phenomena like cavitation,
resulting in significantly higher sound pressure levels.