Planning
ASD 531, Technical description, T 140 416 en
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4.2.1
System limits
The use of an ASD 531 aspirating smoke detector is subject to the system limits listed below and compliance with EN 54-20
requirements. Depending on the planning process, the system limits as set out in Sec. 4.4
also
apply.
Class A
Class B
Class C
Max. overall length of the sampling pipe tube network
75 m
75 m
75 m
Max. length from ASD to farthest sampling hole
40 m
40 m
40 m
Max. number of sampling holes
6
8
12
4.3
Planning aids
4.3.1
Planning with “ASD PipeFlow” calculation
The “ASD PipeFlow” calculation software is used for planning the sampling pipe tube network. Its purpose is to design on a
drawing the pipe layouts required for implementing a system and assign the sampling holes. The “ASD PipeFlow” calculation
software provides a selection of different tube materials, fittings and accessory parts (filter-boxes, water retaining boxes, etc.).
The end result of the calculation software specifies the parameters required for a norm-compliant trigger in accordance with
EN 54-20, Class A to C, after which the parameters are programmed on the ASD 531.
Asymmetrical sampling pipe tube networks can also be planned and set up using the “ASD PipeFlow” calculation software.
System limits for EN 54-20 compliant triggering are defined in the calculation software.
The material stored in the “ASD PipeFlow” calculation software for the sampling pipe – and the “ASD PipeFlow” calculation
software itself – are an integral part of the VdS device approval. A list of the available materials for the sampling pipe is pro-
vided in a separate document (T 131 194).
Fig. 6 “ASD PipeFlow” program interface
Notice about modernising existing systems with the ASD 531
When modernising existing systems (aspirating smoke detectors other than ASD 531), the existing sampling pipe
tube network must be re-calculated using the “ASD PipeFlow” calculation software. The existing sampling pipe
must be cleaned and checked (inspected for damage) prior to commissioning.
