Patent ID: 7111642

Claim:
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 and adapted to open and close 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 open and close the first valve hole while making an axial reciprocating movement into contact with and away from the first valve seat; and opening and closing drive means 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 opening and closing drive means 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 opposite said first valve element adapted to open and close the second valve hole while moving into contact with and away from the second valve seat; a compression spring that urges the second valve element into contact with the second valve seat; electromagnetic valve-opening means 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, and a partition wall which partitions the flow passage and in which the first valve seat of the first valve portion and the second valve seat of the second valve portion are provided, the partition wall comprising an opening portion serving as the first valve hole and the second valve hole, wherein the first valve seat is formed on one side surface of the partition wall and the second valve seat is formed on the other side surface of the partition wall.