These valves were developed for gas turbine control applications but they may be suitable for use in similar harsh environments.
DV4 is used to drain unburnt fuel in case of a failed turbine start or to drain water after washingoperations. DV4 is normally open. The actuator is
pneumatic with spring return and is integrated into the valve body. The valves are suitable for use with combinations of particulate fuel combustion products, diesel/paraffin
type fuel, de-mineralised water and detergent.

The base model DV4 (Mk0) is rated for 250 C. It has no electrical or visual position indication.
DV4 Mk2, Mk3 and Mk4 have a mechanical visual/tactile indicator and may be supplied with micro switches to indicate fully open only; fully closed only; fully open and fully closed or with no switches.
DV4 Mk3 has a hard (metal) seat.
DV4 Mk4 is designed to hold open at a higher inlet/pilot pressure.