Air Sampling Configurations - VESDA VLQ-100 Product Manual

VESDA VLQ Product Guide
3.4

Air Sampling Configurations

Both inlets must be fitted with pipes with 1 or 2 holes and the configuration must comply to the rules in Table 3-1 below.
Table 3-1: Pipe and Sampling Hole Rules
Description
Minimum pipe length per inlet
Maximum linear pipe length per inlet /
combined inlet from detector to furthest
sampling hole
Maximum branched pipe length per inlet
(total)
Maximum distance in branched pipe from
detector to furthest sampling hole
Furthest sampling hole distance from the
detector
Hole sizes per pipe / combined inlet pipe
Maximum capillary length
12
1 hole per 2 holes per Combined
pipe pipe Inlet
15 cm (6 in) 15 cm (6 in) n/a
6 m (20 ft) 6 m (20 ft) 6 m (20 ft)
n/a 9 m (30 ft) n/a
n/a 6 m (20 ft) n/a
6 m (20 ft) 6 m (20 ft) 6 m (20 ft)
1 x 6.5 mm 2 x 4.5 mm 2 x 6.5 mm
(1/4") (11/64") (1/4") or
4 x 4.5 mm
(11/64")
30 cm (1 ft) 30 cm (1 ft) 30 cm (1 ft)
Notes:
Ensure that all sampling holes are from within a single space (not physically
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separated by walls).
Ensure that there is no pressure differential between sampling holes and the
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exhaust port.
Ensure that the number of bends does not exceed four (4) per inlet and per
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branch.
Do not use a single VLQ to perform ceiling and return air grille detection.
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For return air grille detection, the pipe can be routed to the return air grille whilst
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the detector is installed away from the return air grille. The sampling holes must
be oriented 30° to the incoming airflow direction.
Ensure that the air sampling configuration complies to local codes and
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standards.
Ensure that the rules in Table 3-1 are followed when a single hole per inlet or two
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holes per inlet are used.
When the air sampling pipes are unbalanced, for example configurations 2A, 3B,
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4C shown in Table 3-2 below, smoke entering the holes closer to the detector
will trigger an alarm earlier than smoke entering the furthest holes.
VESDA by Xtralis
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