User Manual

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Building Technologies 08-05-930 E
Fire Safety & Security Products
Drilling instructions
Requirements
· The orifice must be drilled correctly, so it corresponds with the coefficient of the VdS calculation software.
Failure to drill the orifice correctly will affect the discharge time of the system and the pressure developed
in the downstream pipework, which may exceed the maximum working pressure rating for the pipe and
fittings.
· Orifice plates are normally supplied drilled to the correct diameter and supplied with the equipment.
· Should undrilled orifice plates be required which are drilled by the local installer, no responsibility is
accepted by Siemens Switzerland Ltd, Building Technologies Group for any defect arising as a result.
Drilling procedure
1. The drilling diameter must correspond with that specified in the VdS calculation.
2. The drilling may have a surface roughness of maximum N8.
3. The drilling must be chamfered with 0.2 x 45° maximum.
4. The drilled diameter must be checked after drilling to ensure it is to the specified diameter,
ø0.5 – ø 3.0 +/- 0.05 mm
5. The drilling diameter must be visibly stamped on the circumference part of the orifice body.
Warning!
If the orifice is not drilled precisely as detailed:
· The pressure after the restrictor can be significantly higher, overstressing the distribution
pipework.
· The discharge time could be prolonged, delaying the achievement of the extinguishant
concentration, resulting in further fire damage.
· The discharge time could be reduced, causing the protected area to be over pressurized during
the discharge, resulting in structural damage.
Any of the above can lead to enormous damage.
Additional documents:
Installation guidelines “07-03-040 E”
Maintenance instructions “07-03-050 E”
Installation guidelines “40-01-010 E”