Securiton ASD 535, Mounting And Installation, Page: 22 / 40

Mounting
22 / 40 ASD 535, Mounting and installation, T 140 333 d en
2.5.8 Making the sampling holes
The hole diameters of the sampling holes have to be deter-
mined and made by the customer as described in section
“Planning” (T 131 192) and the specifications of the
“ASD PipeFlow” calculation software.
The sampling holes must be drilled cleanly so that no burrs or
pressure points result. Use “new” drills with correctly ground
surfaces ( Fig. 12 ).
Whistling noises are a sign that the holes are not clean. The
holes must then be re-drilled or deburred.
For space surveillance, the sequence of the hole diameters as
per section “Planning” (T 131 192) and the specifications of
the “ASD PipeFlow” calculation software must be strictly ad-
hered to.
Fig. 12 Making the sampling holes
If required, the sampling holes can be realized by means of the special “sampling hole clips” (see Sec. 2.5.9).
For equipment monitoring the sampling holes are drilled in the sampling fixture. The sampling holes are drilled in the sampling
fixture so that they face the air outlet of the object to be monitored. If required, these sampling holes can be fitted with sam-
pling funnels (Sec. 2.5.10).
2.5.9 Mounting maintenance and sampling hole clips
Possible only with plastic tubes (PVC/ABS)!
At each required position a hole of Ø 8.5 mm is made in the
sampling pipe (uniform Ø). The holes are made at a right an-
gle to the centre of the pipe axis (as shown in Fig. 12 ).
The sampling hole clips are available in various sizes
(Ø 2.0 / 2.5 / 3.0 / 3.5 / 4.0 / 4.5 / 5.0 / 5.5 / 6.0 / 6.5 / 7.0 mm).
For determining the required sampling hole clips, refer to sec-
tion “Planning” (T 131 192) and the specifications of the
“ASD PipeFlow” calculation software.
The sampling hole clips and the maintenance clips are clipped
onto the sampling tube so that they snap onto the 8.5 mm
hole, Fig. 13 .
Fig. 13 Mounting clips
2.5.10 Mounting the sampling funnel
Possible only with plastic tubes (PVC/ABS)!
For equipment monitoring objects with a high air flow rate
(strong ventilation), the sampling holes can be fitted with fun-
nels for optimal detection of smoke.
If forced ventilation is used in rooms and/or for equipment, the
use of sampling funnels is imperative.
The sampling funnels are fastened to the tube of the sampling
fixture and adjusted on the previously drilled sampling holes
as described in Fig. 14 .
Fig. 14 Using sampling funnels
Angled hole
Pressure points
Burrs
wrong
correct
Hole not at
pipe centre
If whistling noises,
deburr or countersink
Sampling hole
Sampling
hole
clip
Maintenance
clip
Maintenance
sampling hole,
Ø 8.5 mm
Hole,
Ø 8.5 mm
PVC or ABS
sampling tube
Screws,
M4 x 25
Click pipe clamp
Top part
of funnel
Tube of
sampling fixture
Sampling hole
Bottom part
of funnel
Funnel
opening
Funnel opening
Sampling funnel
Support rail