BS EN 13160-1:2016 pdf download – Leak detection systems Part 1 : General Principles
4 Classes of leak detection systems For the purpose of this standard the following classes apply in order of protection for the level of safety or environmental protection required: Class I: Systems of this class will detect a leak above as well as below the liquid level in a double-skin system. They are inherently safe and will detect a leak before any liquid can enter the environment (i.e. pressure or vacuum systems).
Class II: Systems of this class will detect a leak above as well as below the liquid level in a double-skin system with the possibility of the leak detection liquid leaking into the environment (i.e. liquid monitoring system).
Class III: Systems of this class will detect a leak below the liquid level in a tank or in a pipework system. These systems are based on liquid and/or vapour sensors located in leakage containment or interstitial space. A possibility exists of product entering the environment.
Class IV: Systems of this class will detect, to specific levels of probability, specified rates of change of tank contents (i.e. leakages into or out of the tank). A strong possibility exists that product will enter the environment in the event of a leak.
Class IV A: Dynamic leak detection systems will by reconciliation also indicate leaks in the connected pipework.
Class IV B: Static tank gauge leak detection systems or statistical quiet period leak detection systems will only indicate leaks in a tank.
Class IV C: Pressure line leak detection system which will detect a leak in pressurized pipework, only when no product is being dispensed.
Class V: Systems of this class may detect liquid loss in tanks or pipework below the liquid level. Product will enter the environment before the leak is detected (i.e. sensors of class III in monitoring wells). For examples for the different classes see Annex A.
5.1 General Leak detection systems shall trigger the alarm in the event of a leak or in the event of malfunctions of the leak detection system. All leak detection systems shall indicate every leak by a visual and audible alarm. In the event of a power interruption, the leak detection system shall be designed to resume normal operation on the restoration of the power supply. Leak detection systems shall be designed for operation under atmospheric conditions according to 3.1.
Leak detection systems and/or their components intended for installation in a potentially explosive atmosphere shall be explosion protected. If there exists the possibility of an explosive atmosphere being present within the leak detection system and/or its components these shall be explosion protected.
The leak detection systems shall be designed for installation in such a way to prevent accidental disconnection of the equipment’s power supply.
Plug and socket connections or switches are only permitted if their interruption triggers off an alarm. For a leak detection system using liquid the interstitial space shall be equipped with a test nozzle above the liquid level in the inner tank.
The leak detection system shall be capable of being tested or capable of simulating a leak condition. Disconnections of any sensor or transducer or a short circuit in connecting cables shall result in an alarm condition. All indications and sounders shall be capable of being tested. The leak detection systems shall be designed so that correct operation can be verified.
The leak detection systems shall be used and maintained in accordance with the manufacturer’s instruction.
If a leak detector serves more than one tank or pipework equipment is required which shows or allows to test in an event of an alarm which tank or pipework leaks. 5.2 Avoidance or reduction of ignition sources All electrical and non-electrical equipment and components, intended for use in potentially explosive atmospheres, shall be designed and constructed according to good engineering practice and in conformity with the required categories for group II equipment to ensure avoidance of any ignition source.
To classify the category of the equipment it shall be subjected to an ignition hazard assessment in accordance with 5.2 of EN ISO 80079-36:2016.
Device categories for explosion-proof parts of the leak detection systems see Annex B. Where regulations require, the leak protecting lining used in a conductive tank shall be conductive with a surface resistance of less than 1 × 10 9 Ω in order to dissipate any electrostatic charges if the stored product has a flash point of < 55 °C.
This requirement shall be tested according to EN 61340-4-1. Where the leak protecting lining has a greater surface resistance than 1 × 10 9 Ω an object shall be inserted in the stored product which is capable of dissipating the electrostatic charges loads, either 1) a steel plate with a surface of (0,04 × V t ) in m 2 in which V t is the volume in m 3 of the tank or 2) steel filling, dipping and/or suction pipes which have a total surface as indicated above. In both cases the object inserted in the stored product shall have provision for earthing with a resistance less than 1000 Ω.BS EN 13160-1 pdf download.