BS EN 13922 pdf free download
BS EN 13922-2020 pdf free download.Tanks for transport of dangerous goods — Service equipment for tanks — Overfill prevention systems for liquid fuels.
4 Functions 4.1 To prevent overfilling of the tank-vehicle’s compartment by providing a fail-safe output to a gantry control system.
4.2 To provide a failsafe monitored earthing connection from the gantry to the tank-vehicle’s shell via a bonding connection to the tank-vehicle’s chassis.
4.3 To provide visual indication of the status of the overfill prevention system.
5 Major components
5.1 Tank-vehicle mounted equipment The following equipment shall be installed on the tank-vehicle as a minimum:
— one sensor or sensor circuit per compartment;
— one 10 pin socket;
— wiring to the sensors;
— earthing provision.
5.2 Equipment fitted at the gantry The overfill prevention equipment mounted on the tank truck is operable when the following equipment is installed at a loading gantry:
— overfill prevention controller;
— one 10 pin plug and cable for connection to tank-vehicle socket.
5.3 Optional equipment The overfill prevention system can provide the vapour collection detection safety interlock which prevents loading unless the vapour collection hose is connected to the tank-vehicle and the vapour transfer valve(s) is (are) open.
6 Characteristics
6.1 Overfill prevention system working characteristics
6.1.1 Overfill The overfill prevention system shall be an electronic system, gantry based and gantry operated. The interface wiring shall be suitable for a two-wire or a five-wire overfill prevention system and the gantry based controller shall automatically detect the difference between either overfill prevention system through a standardized 10 pin plug and socket
— see Figures A.2 and A.3
— and perform its functions. Electrical specifications for the interface are included in Annex A. The overfill prevention controller shall only provide a permissive signal to permit loading if, once connected, there is no system fault and no sensor is wet. Upon an overfill condition or the detection of any overfill prevention system or controller fault, the controller shall switch to non-permissive state.
The overfill prevention system shall be fail safe and shall be self-checking. The effective cycle time between self-checks shall be less than the overfill response time. The overfill prevention response time shall not exceed 700 ms. The overfill prevention system shall be capable of handling up to and including the following number of compartments for each type of installation:
— Two-wire system 8 compartments;
— Five-were system 12 compartments. No signals other than those defined in the standard are allowed.
6.1.2 Earthing The overfill prevention system shall provide an electrical connection from the gantry earth to the tank- vehicle chassis via the cable and connection plug and socket and shall continuously verify this connection throughout the loading operation. To comply with the transport regulations (ADR), a good electrical connection from the tank vehicle chassis to earth shall be established before tanks are filled or emptied. Should the electrical resistance of the connection exceed a maximum of 10 kΩ, the gantry controller shall switch to non-permissive state. 6.1.3 Severe environmental condition Where the overfill prevention system is subjected to temperatures outside the specified temperature range all applicable temperature values shall be extended. All other requirements shall remain unchanged.
6.1.4 Requirements for electromagnetic compatibility (EMC) The overfill prevention system shall fulfil the requirements of:
— EN 61000-6-4 for emission;
— EN 61000-4-3 for immunity.
6.1.5 Circuit interlock (optional) When included within the overfill prevention system, the circuit interlock (switch) shall provide the function of the vapour collection detection interlock described in 5.3 and shall be connected as shown in Figures A.4 and A.5.BS EN 13922 pdf download.
