The LDU11.523 control box valve proving system is designed for use with shutoff valves in connection with gas burners and gas appliances. In the event of inadmissible leakage, the system prevents the burner from starting up. The LDU11.523 system conforms to the requirements of EN1643 covering automatic shutoff valves for use with gas burners and gas appliances to EN161.
The LDU11.523 is designed for automatic gas valve proving (leakage test) based on the pressure proving the principle. It is for use on gas-fired combustion plant with or without vent pipe to atmosphere. In the case of plants with no vent pipe where EN standards apply, the notes are given in «Connection examples without vent pipe to the atmosphere» must be observed.
If the pressure increases excessively during the first test phase called «Test1», or decreases excessively during the second test phase called «Test2», the LDU11.523 will inhibit burner startup and initiate lockout. In that case, the lockout reset button will light up to indicate the fault. Remote indication of the fault is also possible. A program indicator, which stops whenever a fault occurs, indicates which of the valves is leaking. The LDU11 can be reset either on the unit itself or via an electric remote reset facility.