Vision Systems VESDA, Руководство по конструкции

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Refrigerated Storage Design Guide
VESDA
®
Figure 4 – Example of pipe
penetration with an insulation
boot and drip tray
In order to avoid condensation formation at the penetration point, the section of pipe exiting the
protected area MUST be insulated as shown (Figure 4). A tray can be used to collect any water
condensation on the pipe surface.
3.5 Compensating For Sample Pipe Contraction
Mounting clips, used to secure VESDA pipes to the ceiling, MUST not restrict longitudinal
movement of the pipes as they expand or contract due to temperature variations. This is especially
important where the pipe network is installed before the refrigerators are turned on. For example,
according to its thermal expansion coefficient, an ABS pipe will contract by 0.1% for every 10°C
(50°F) drop in temperature. This equates to a 40 mm (1.57 inch) reduction in length for a 40 m
(131.2 ft) pipe and will result in disconnection of pipe sections in cases where the pipes were
installed in temperatures well above the intended operating temperature.
Note: Refer to Table 3 for the thermal properties of other commonly used pipe materials.
To prevent pipe disconnections, make allowance for pipe contraction along the length of the pipes.
Saddle or offset clips should be use to secure the VESDA pipes to the ceiling as shown below
(Figure 5).
Saddle Clip
Offset Clip Pipe Clip (UK)
Figure 5 – Examples of pipe network supports.
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