Honeywell Valve Proving System

A4021A1002 – Valve Proving System

The A4021 is a self-checking microprocessor based valve proving system. The A4021 checks the effective closure of automatic shut-off valves by measuring the pressure differential between two valves during the test sequence. Plug-in base and pressure switches are required to complete the system.

When during the test sequence of the A4021 a failing valve is detected, the A4021 will go into a non-volatile lock-out status, generates an alarm and prevents a burner start-up. The intended application is for gas fired power burners and other large capacity gas firing installations, where according to the European norm EN676 a valve proving system can be used as an alternative for pre-purging the combustion chamber. And for installations with or without pre-purge with a capacity of more than 1200 kW.

Download in PDF