4.5. Anticipated failures and precautions
4.5.1. Breakdown of non-return valves
•
Close valves when not in use.
•
Examine valves once a year by authorized per-
sonnel.
4.6. Residual risk
4.6.1. Damaged unit:
•
Do not use if isolation valves cannot be operated
or required operation cannot be selected.
•
Never use the unit if it has been dislodged from
its original place of mounting.
4.6.2. Repair of unit:
•
Do not attempt to repair a unit by yourself. Always
contact an authorized service company.
•
Block and mark any defect unit in order to avoid
unintended use.
•
For safety reasons only use approved and origi-
nal spare parts.
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