VESDA VLF-500, Руководство по эксплуатации продукта

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VESDA by Xtralis VESDA VLF-500 Product Guide
www.xtralis.com 23
3.4 Installation Considerations
Note: For code-specific information, refer to Codes and Standards Information for Air Sampling Smoke
Detection on page iii.
The VESDA VLF provides very early warning smoke detection specifically for small environments.
The pre-engineered pipe network designs can support up to 8 sampling holes for single pipes and 12 sampling
holes for branched pipe arrangements. The number of sampling holes used can be increased to 24, however,
ASPIRE will need to verify that the additional sampling holes can be supported. Sampling holes are positioned
according to the standards relating to conventional point detector placement.
The pre-engineered pipe network solutions described in Section 3.1 on page 20 and Section 3.2 on page 21
achieved transport times of less than 60 seconds for open hole sampling and less than 90 seconds for
capillary sampling.
Where the VESDA VLF is located outside the protected area (e.g. in a corridor outside the room),
consideration must be given to returning the detector exhaust air to the protected environment to balance the
pressure differences that may exist. In the majority of applications, this is not necessary as pressure
differences are minimal. The exhaust should also be returned to the protected area in cases where there are
hazardous substances inside the protected area, eg hospital operating theatres. Where practical
considerations fall outside pre-engineered designs or where pressure differences exceed 50 Pa, in situations
where the detector is located outside the protected area, the solutions presented in this manual may not be
suitable and it is recommended that alternate designs are verified by a suitably qualified installer using
ASPIRE.
The following points should be considered when installing the sampling pipe:
l
minimize flexing in sampling pipes by supporting the pipe every 1.5 m (5 ft) or less, or at a distance
described in local codes and standards
l
evenly arrange the sampling pipe network over return air grilles
l
sampling pipe fits firmly into the tapered detector port, DO NOT glue this connection
l
allow sufficient movement at the detector to permit pipe removal for maintenance
l
keep the exhaust deflector fitted to prevent foreign objects falling into the detector
l
keep the return air pipe as short as possible to minimize airflow resistance in the pipe
l
pipe ends must be made smooth for bonding
l
sampling holes must be drilled in line and perpendicular to the pipe
l
sample holes must be clear of rough edges and debris
l
pipes are free of debris
l
all joints must be bonded except the endcaps and pipes entering the detector
Notes:
l
In protected areas sampling holes should face into the direction of airflow, or point downwards in static
airflow situations. When variable flows are present, position the sampling holes at 30° to the airflow.
l
You should try to keep the sampling holes evenly spaced.
l
For code-specific information, refer to Codes and Standards Information for Air Sampling Smoke
Detection on page iii.
3.5 Air sampling in a duct
For air sampling in a duct please refer to the VESDA System Design Manual for duct probe design. For code-
specific information, refer to Codes and Standards Information for Air Sampling Smoke Detection on page iii.