OVERPRESSURE – LEAK DETECTOR DL ..
2.4 Exclusion
If permeation occurs in the interstitial space as a result of the stored product and the material
structure of the inner tank wall (e.g. in double-walled GRP tanks) which can result in an
explosive atmosphere in the interstitial space under normal operating condition, ONLY leak
detector DLG .. must be used in combination with an inert leak detection medium (pressure
cylinder or operational network).
3 Description of functions
The overpressure leak detector DL .. resp. DLG .. monitors both walls of a tank for leaks. The
monitoring pressure is high so that any leaks above or below the liquid level (stored product and
ground water) are detected as a fall in pressure.
Pressure is built in up in:
DL ..
by sucking in the
outside air
through the
integrated pump via a dry filter and forwarding it
to the interstitial space.
The dry filter dries the air to approx. 10%
humidity. Drying is necessary to prevent
moisture/condensation from collecting in the
interstitial space.
Spent dry filter fillings must
be regenerated or replaced.
DLG ..
by conveying compressed gas (dried air or
intert gas) to the interstitial space. The leak
detector has a display in the housing lid which
shows the operating pressure in the interstitial
space.
•
Values under 50 mbar or under 0.73 PSI are
not shown.
•
Values between 50 and 999 mbar are shown
in mbar without decimals.
•
Values from 1 bar are shown in bar with 2
decimal places and from 10 bar with 1 decimal
place.
•
Values in PSI are shown with 1 or 2 decimal
places.
3.1 Switching and pressure values
Annex B contains a list of the switching values.
3.2 Normal
operation
The overpressure leak detector is connected by pressure and measuring line with the interstitial
space(s). The overpressure created by the pressure generator (pump or pressure cylinder) is
measured and controlled by a pressure sensor.
On reaching the operating pressure (refill OFF), the pressure generator (pump or solenoid
valve) is switched off. The pressure slowly falls again due to unavoidable leaks in the leak
detection system. On reaching the switching value for "refill ON", the pressure generator is
switched on again and operating pressure restored.
In normal operation, the leak detector swings between these two pressure values with short
operational times and longer standstill periods, depending on the level of tightness and
temperature fluctuations in the system.
26/01/2006
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Summary of Contents for DL 100
Page 20: ...Ex Ex Ex 17 102 72 73 43 13 27 11 2002 M1 060 000 76 30 21 20 70 20 von 49 ...
Page 21: ...Ex Ex Ex 73 73 73 230 V 50 Hz 21 02 43 20 13 72 27 11 2002 M2 060 000 71 69 01 09 21 von 49 ...
Page 26: ...22 84 85 85 22 52 98 98 0 Kl 1 0 17 12 2002 P 115 392 21 21 20 20 90 90 26 von 49 ...
Page 34: ...28 06 2005 Drilling Dimension 200 300 260 220 T 140 8 34 von 49 ...
