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Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
5.2 Globe valve requirements
Responsibility
If there is a risk of solids contained in the process medium causing blockage,
a strainer must be fitted.
Safety equipment with fail-open action must not be operated with
strainers.
To reduce friction, it is preferable to use spring-loaded stem packings. Adjustable stem
packings are to be tightened by qualified staff only to prevent the stem from beco-
ming blocked.
To prevent corrosion of the actuator springs, measures must be taken to prevent water
or moisture from entering the actuator. Such measures include fitting a venting pipe or
air purging of the actuator‘s spring chamber.
Operator
Operator
Example:
Control and quick-acting shut-off valve with air purging of the
actuator‘s spring chamber
Example:
On-off valve with air purging of the actuator‘s spring chamber
Suitable measures must be taken to ensure that the venting port of the solenoid valve
is kept open.
Example: Venting pipe on the solenoid valve
Manufacturer/
operator
