VESDA VLC, Руководство по обслуживанию

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VESDA VESDA Maintenance Guide
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5 Sampling Pipe Network Maintenance
5.1 Important Pre-maintenance Preparations
Every six months, you should perform a visual check for any damaged sampling pipes or pipe junctions and
do repairs as necessary. If damaged or blocked sampling pipes go unrepaired, detector flow faults can occur.
Prior to isolating the VESDA system for maintenance, the following important steps must be taken:
1. Inform appropriate supervising authorities about the risk associated with isolating an Address.
2. Ensure that any ancillary devices, dependent on the detector, are appropriately isolated.
Warning: Inhalation of dust is hazardous to health. Dust build up may contain potentially dangerous toxic
materials. All cleaning processes must be suitably modified in such instances to negate the risk
from toxic materials. Adequate precautions must be taken to comply with local health and
safety regulations.
5.2 Wide Bore Sampling Networks
5.2.1 Cleaning the Sampling Network
Cleaning of the sampling network (sampling pipe and sampling holes or capillaries) is of paramount
importance to ensure reliable detection of smoke. For environment classes 1 & 2, it is recommended that the
sampling pipe network be maintained every two years, however, more frequent maintenance intervals will be
required depending on site conditions (refer to Appendix B on page 49).
Note: Local code guidelines may require more frequent inspections for all classes.
Where possible, sampling pipes and their connections should be checked to ensure that the pipe runs are
intact and that the network is free of dirt and dust.
Follow the instructions below to clean your sampling pipe network:
1. Ensure that detectors are isolated from the monitoring panel and fire suppression systems.
2. Notify the relevant authorities that the work is being performed.
3. Check and record the current airflow for before and after comparison.
4. Disconnect the detector power supply.
5. Remove all pipes from the detector inlet(s) and exhausts then cover them to ensure that no further dust
can enter the detector.
6. Ensure that end caps are set firmly in place.
7. Connect a vacuum cleaner to the detector end of each pipe in turn. When turned on, it will extract dust and
contaminants that have built up inside the pipes. This method is recommended to avoid introducing
debris/dust in areas housing mission critical equipment (IT, EDP, clean rooms, etc.).
8. Alternatively, introduce compressed air (400 KPa for 2 minutes) at the detector end of each pipe in turn to
blow dust and contaminants out through the sampling holes. Take precautions to ensure that dust is not
blown into undesired areas.
9. Visually check that the in-pipe sampling holes have a clear air path.
10. Compare the before and after flow rates. Ideally, the flow should be close to 100% for each used pipe. If
this is not the case, the sampling holes/capillaries and detector may need closer inspection.
11. Once the system has been serviced, cleaned, tested and is operating fault-free, return it to its normal
operating mode.
For in-duct sampling remove the pipe(s) from the duct and follow the cleaning process. Once cleaning is
complete, return the pipe(s) to their original angle to the incoming airflow.
Sites with dirty environments, which require very regular sampling pipe and sampling hole cleaning, should
consider installing automated equipment to assist with regular cleaning schedules.