Xtralis VESDA VLC-505, Manual

Page: 312 / 367

VESDA Pipe Network Installation Guide VESDA by Xtralis
14 www.xtralis.com
Legend
A Expansion joint
B Standard pipe joint
Figure 4-4: Expansion joints
The diagram above shows expansion (A) and standard (B) pipe joints. The diagrams at the top show how the
pipe network will look at room temperature, the diagrams at the bottom show what happens after the
refrigeration system has been turned on and the pipe shrinks. Note that once the standard pipe has shrunk the
pipes are no longer air tight and the detector will not be able to detect smoke.
U bend arrangement
It is important to allow for the expansion or contraction of the sampling pipes where there is likelihood of high
level of temperature fluctuations. It is recommended to use 'U' bends in longer pipe runs to prevent buckling.
Refer to Figure 4-5.
Figure 4-5: U bend
4.4 Mounting
The pipe network should be mounted as per the design and ASPIRE specifications. The fittings used for
mounting will depend upon the design and site requirements.
l
To minimize flexing the pipes should be secured every 1.5 m (5 ft.)
l
Pipes should be suspended between 25 -100 mm (1 - 4 inches) below the ceiling
Note: This is subject to local codes and standards and pipe network design specifications.
l
Where expansion or contraction of pipes is likely either after installation or on a continuous basis, place
pipe clips 0.5m (1.5 ft) away from any bends, couplings and socket unions as these may interfere with
the movement of the pipe. It is recommended to use appropriate pipe supports which don't clamp
securely around the pipe, thus allowing the pipe to freely expand and contract within.
l
Refer to Chapter 5 for details on mounting requirements for specific types of installations.