AIR/GAS PRESSURE - LIQUID SYSTEM - TANK GAUGING

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QUESTION AIR/GAS OVER PRESSURE
LEAK DETECTOR
TANK GAUGING SYSTEM WITH
SENSOR IN THE INTERSTICE
Are both walls permanent
monitored for tightness?
YES
With the overpressure in the interstice
both walls are monitored permanent.
An alarm will be released before any
product even can enter the interstice.
Only air / gas enters the stored produkt
NO
The gauging system only can monitor the inner wall below the liquid level for unacceptable losses.
The outer wall is not monitored.
The sensor will give an alarm only if it gets into contact with liquid.
Exclusion of environmental
contamination and product
losses in case of a leak in
the inner wall?
YES
The overpressure keeps the product in the inner tank.
Only air / gas enters the stored produkt
NO
Product enters the interstitial space, the sensor will detect liquid, but the sensor can not indicate wether the outer wall is still tight or not. There is still a risk of product leaking into the environment.
Can system testing be done
without access to tank?
YES NO