SGB DLR-GS PMN Series, Документация

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OVERPRESSURE LEAK DETECTOR DLR-GS ..
10/09/2014
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
The resistance of the pipeline/fittings to the material being conveyed must be verified by
third parties (e.g. operator, manufacturer of the pipeline/fittings ....)
3. Description of functions and operation
The overpressure leak detector DLR-GS monitors both walls of the double-walled system for
leaks. The monitoring pressure under normal operating conditions is higher than any other
pressure applied to the inner or outer wall, so that leaks are indicated through a drop in
pressure.
The leak detection medium used can be an inert gas or air from a pressurised gas canister or
gas network (with the use of a suitable pressure reducer). If air is used, it must be dried to less
than 10% relative humidity.
If the current pressure is shown in mbar/bar or in PSI
1
on the optional display screen, the
following applies:

Values under 150 mbar or 2.18 PSI are not displayed.

Values between 100 and 990 mbar are displayed in mbar without any decimal places.

Values >1 bar are displayed in bar to two decimal places, values >10 bar to one decimal
place.

Values in PSI are displayed to one or two decimal place(s).
3.1. Switching values and pressure values
A list of switching values is shown in Appendix B.
3.2. Normal operation
When the detector is put into operation, the normal operating state is achieved by building up
pressure to the setpoint via a pressure accumulator (normally mobile).
The pressure applied in the interstitial space is monitored in the leak detector by a pressure
sensor. Any small leakages result in a drop in pressure. That means that the interstitial space(s)
and connecting pipes are subject to very high requirements of leak tightness if a full year of
fault-free operation is to be ensured.
3.3. Functions in the event of a leak
If a leak occurs on the inner or outer wall then gas will escape from the interstitial space. The
pressure drops.
When the alarm pressure is reached, an alarm (visual and acoustic) is triggered, and the
potential-free contacts open.
1
The display is preset to bar or PSI at the manufacturing plant, but this setting can also be carried out on
site upon consultation with the manufacturer.