<p>This valve, is of the type including a core moving alternatingly between two seats inside a casing to assume respectively its operative and inoperative positions and cannot be re-energized automatically when a transient drop in pressure has caused its de-energization. This safety feature, which is important when the valve controls a circuit-breaker, is obtained through a throttled connection between the annular clearance surrounding the core and adapted to be connected with an outlet and fluid-filled chambers at both ends of the casing. Said connection may comprise bores extending within the core.</p>
