The DUNGS VPS 504 S06 is a valve proving system for DMV series safety valves. It checks that both safety valves in a DMV series gas train are fully closed before either a system startup and/or after system shutdown when wired and interlocked to a suitable flame safeguard control. The VPS 504 S06 will halt the startup sequence to a burner if it detects an open safety shutoff valve, thus preventing ignition under undesirable conditions.