The high-pressure pumps are stopped by activation of the emergency stop push button, the zone
struck by fire shall be isolated at the section valve, and the pump system shall be re-established in
order to serve sections other than the section struck by fire.
Reestablishment of the SEM-SAFE
®
system after starting up 4.4
If the system has been activated, the following procedure must be followed to bring the system back to
the ready state.
1. The nozzle(s) which is/are released are to be changed. This is done after closing the section
valve for the section concerned.
2. After mounting new nozzles, the section where the release has taken place is to be pressure-
tested with operation pressure to secure that the system is tight. In practice, this is done by re-
opening the section valve for the section concerned and letting the high-pressure pumps, which
are still running, raise the pressure in the section. When the section concerned has been re-
pressurized, the section valve is closed again and the total system is de-pressurised by means of
the relieve button.
3. The section concerned is now the only one pressurised to operational pressure. Please observe
whether the pressure in this section is falling – this would indicate a leakage. If not, the section
is ready for stand-by operation. The replaced nozzles are checked for leakages. Finally, the
section valve is re-opened.
4. By a release of the system (i.e. all sections have been pressurized), in order to bring the system
back to normal operation procedure (stand-by function), the system is to be de-pressurized
using the “Relieve System” button.
The “Relieve System” button functions as follows:
1. All high-pressure pumps are stopped.
2. The by-pass valves on the pump unit and main risers are opened until the pressure drops to 12
bars.
3. System alarms are reset.
4. High-pressure pump stop is deactivated.
After this procedure, the system is back at stand-by function and ready to start up again should it be
necessary.
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