Valve having fast and slow acting closure elements

A valve comprising:

• a valve casing having a flow passage defined therein and having a fluid inlet portion and a fluid outlet portion;
• and
• a first valve portion and a second valve portion which are arranged in series in the flow passage adjacent a partition wall,
• the first valve portion comprising a first valve seat on said partition wall and a first valve element and a rotary motor for shifting said first valve element between a first position engaging the first valve seat to seal the flow passage and a second position spaced from the first valve seat;
• and
• the second valve portion comprising a second valve seat on said partition wall and a second valve element resiliently biased toward said second valve seat and an electromagnetic actuator for shifting said second valve element between a first position engaging the second valve seat to seal the flow passage and a second position spaced from the second valve seat.

A valve comprising:

• a valve casing having a flow passage defined therein and having a fluid inlet portion and a fluid outlet portion;
• and
• a first valve portion and a second valve portion which are arranged in series in the flow passage,
• the first valve portion comprising:
• a first valve seat having a first valve hole and partitioning the flow passage;
• a first valve element supported by a first valve shaft and adapted to axially reciprocate toward and away from the first valve seat and the second valve portion;
• and
• a drive for causing the first valve shaft to make a reciprocating movement and capable of effecting a flow rate control and slow valve-opening for the flow passage, the drive comprising a motor and a motion converting mechanism that converts a rotary motion into a linear motion,
• the second valve portion comprising:
• a second valve seat having a second valve hole and partitioning the flow passage;
• a second valve element adapted to open and close the second valve hole while moving into contact with and away from the second valve seat and toward and away from the first valve portion;
• a compression spring that urges the second valve element into contact with the second valve seat;
• and
• an electromagnetic valve opener for moving the second valve element away from the second valve seat by an electromagnetic force and capable of effecting quick valve-closure for the flow passage.