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REV. STV20110519
4.4
Diaphragms
4.4.1 Interval of diaphragm inspection
The service life to the valve diaphragm depends on its working conditions. Important factors
with regard to the service life are temperature and the type of process and CIP fluid (s).
In general, inspection should be made at every 50 hours of sterilization (e.g. exposure to steam or
superheated water) or 1000 hours of operation, whichever occurs first.
The interval may however vary between different installations, depending on the diaphragm
material, chemicals and utilities used, and temperature during SIP.
NOTE:
Once the diaphragm has been replaced, please make sure that the actuator is in open position
before mounting the actuator to the valve.
4.4.2 Inspection procedure
Any leakage from the diaphragm will be indicated by fluid seeping from a telltale hole at the
bottom of the actuator.
DANGER!
The inspection must be carried out while the valve is free from harmful chemicals,
cold, and not pressurized. Negligence may result in personal injuries.
When inspecting the diaphragm:
Shut down the system (pumps etc) and purge all pressure.
Secure that the system is clean, drained, ventilated and below 55°C.
Follow the instructions shown below:
