Abstract: An air control circuit including a safety function is simply formed from an air circuit. An air control circuit includes a main air line that controls an air device by concurrently turning on or off two external-pilot-operated electromagnetic valves, a pilot air line that supplies pilot air to the electromagnetic valves, and a pilot control line that switches the pilot air line between a supply state and an exhaust state. When one of the two electromagnetic valves suffers a breakdown to fail to be switched to an off position, air in the air device is exhausted through the other electromagnetic valve that has been switched to the off position to recover the air device, and the pilot air line is switched to the exhaust state by the pilot control line to prevent the two electromagnetic valves from restarting.

Abstract: A vacuum valve includes a main flow channel that connects the first port and the second port, a main valve seat that surrounds the main flow channel, a main valve disc that opens and closes the main flow channel by contacting and separating from the main valve seat, a sub-flow channel that is formed inside the main valve disc, a sub-valve seat that is formed on an outer surface of the main valve disc, a sub-valve disc that opens and closes the sub-flow channel by contacting and separating from the sub-valve seat at a position outside the main valve disc, and a rod that causes the main valve disc and the sub-valve disc to open and close. The sub-valve disc opens and closes the sub-flow channel by being operated directly by the rod, and the main valve disc opens and closes the main flow channel by being operated via the sub-valve disc by the rod.

Abstract: A vacuum valve includes a main flow channel that connects the first port and the second port, a main valve seat that surrounds the main flow channel, a main valve disc that opens and closes the main flow channel by contacting and separating from the main valve seat, a sub-flow channel that is formed inside the main valve disc, a sub-valve seat that is formed on an outer surface of the main valve disc, a sub-valve disc that opens and closes the sub-flow channel by contacting and separating from the sub-valve seat at a position outside the main valve disc, and a rod that causes the main valve disc and the sub-valve disc to open and close. The sub-valve disc opens and closes the sub-flow channel by being operated directly by the rod, and the main valve disc opens and closes the main flow channel by being operated via the sub-valve disc by the rod.

Abstract: A poppet valve seal mechanism has a groove to which a seal member is mounted such that a width of an opening of the groove is smaller than a maximum width inside of the groove and a cross section area of the groove is smaller than that of the seal member. A maximum width of a portion of the seal member accommodated in the groove is greater than a width of the opening of the groove. A width of the opening is constant over its entire peripheral. An inner wall forming the inside of the groove is formed with communication holes and which bring the inside of the groove and the outside of the groove into communication with each other.

Abstract: To provide a maintenance-easy two-port valve capable of easily assembling and disassembling a valve body and a bonnet, and preventing the bonnet from being detached from the valve body by an erroneous operation. In a two-port valve 1 having attachment means for detachably attaching a bonnet 21 to a valve body 2, the attachment means includes a plurality of shafts 16 fixedly attached to a valve body 2 and each having an engagement groove 17 on an upper end portion, a handle 31, a plate 41 rotatably provided between an upper end portion of the bonnet 21 and the handle 31 and having an engagement groove 43 engaged to or disengaged from the retaining groove 17 by rotating the plate 41, and an engagement pin 35 engaged with an engagement hole 44 provided in the plate 41 at a push-down position of the handle 31, transmitting the rotation of the handle 31 to the plate 41 and fixedly attached to the handle 31.

Abstract: A magnet is attached to a piston which slides in the interior of a casing due to action of fluid pressure, a guide groove is provided on a side face of the casing in a movement direction of the piston, an indicator is received in the guide groove, and at least one portion of the indicator is formed of a magnetic body, so that the indicator can displace following the piston.

Abstract: A magnet is attached to a piston which slides in the interior of a casing due to action of fluid pressure, a guide groove is provided on a side face of the casing in a movement direction of the piston, an indicator is received in the guide groove, and at least one portion of the indicator is formed of a magnetic body, so that the indicator can displace following the piston.

Abstract: To provide a maintenance-easy two-port valve capable of easily assembling and disassembling a valve body and a bonnet, and preventing the bonnet from being detached from the valve body by an erroneous operation. In a two-port valve 1 having attachment means for detachably attaching a bonnet 21 to a valve body 2, the attachment means includes a plurality of shafts 16 fixedly attached to a valve body 2 and each having an engagement groove 17 on an upper end portion, a handle 31, a plate 41 rotatably provided between an upper end portion of the bonnet 21 and the handle 31 and having an engagement groove 43 engaged to or disengaged from the retaining groove 17 by rotating the plate 41, and an engagement pin 35 engaged with an engagement hole 44 provided in the plate 41 at a push-down position of the handle 31, transmitting the rotation of the handle 31 to the plate 41 and fixedly attached to the handle 31.

Abstract: To provide a poppet valve seal mechanism in which a seal member does not fall out from a groove, and the metal touch is not generated. A groove 15 to which a seal member 17 is mounted is formed such that a width of an opening 15a of the groove 15 is smaller than an maximum width of inside of the groove 15 and a cross section area of the groove 15 is smaller than that of the seal member 17. A maximum width of a portion of the seal member 17 accommodated in the groove 15 is greater than a width of the opening of the groove. A width of the opening 15a is constant over its entire peripheral. An inner wall forming the inside of the groove 15 is formed with communication holes 33 and 34 which bring the inside of the groove 15 and the outside of the groove 15 into communication with each other.

Abstract: An opening/closing valve has an attachment/detachment mechanism for detachably interconnecting a valve body and a bonnet. The attachment/detachment mechanism comprises a first annular groove provided at a connecting recess of the valve body, a second annular groove provided at a connecting projection of the bonnet, and an elastic semiannular member. The elastic semiannular member is installed to the first annular groove and the second annular groove respectively when the valve body and the bonnet are interconnected.