Abstract: A valve (10) of an embodiment of the present invention has a tapered section (55) on an opening side of a depression (51a) of a body (1). When a projection (4b) of a ball (4) is inserted into the depression (51a), a part of a tip end edge of the projection (4b) is brought into contact with the tapered section (55), and the tapered section (55) guides the projection (4b) so that the entire circumference of the tip end edge of the projection (4b) is located on a bottom side with respect to the tapered section (55).

Abstract: Realized is a sealing member which exhibits excellent sealing properties even at a low temperature and a high pressure. A sealing member (100) includes: a first pressing part (110) that presses a first side part of a gap by pressing from a lateral direction; a second pressing part (120) that is pressed against a second side part of the gap by the pressing from the lateral direction; and a part (122) that induces deformation of the sealing member (100) such that the sealing member (100) is strained toward the second side part by the pressing from the lateral direction.

Abstract: A valve (10) in accordance with an embodiment of the present invention includes a body (1) having a space in which a stem (3) and a ball (4) are housed, wherein an inner lid body (60) fixing the ball (4) in the space liquid-tightly partitions the space into a part in which the stem (3) is housed and a part in which the ball (4) is housed.

Abstract: A trunnion-type ball valve, a valve seal structure, and a valve packing in which, a seal surface pressure of a tip outer peripheral region is improved. A ball (3) provided inside a body (2) is rotatably provided via upper and lower stems (4 and 5) and is sealed with a ball seat (6). The trunnion-type ball valve has a packing attached between an outer periphery step part provided at a rear part of the ball seat and the body and a pressing mechanism by which the packing is pressed to a ball direction, and is provided with a contact surface to be contacted with a step part surface of the outer periphery step part on a tip outer diameter side of the packing and a space provided between the packing and the step part surface of the outer periphery step part on a tip inner diameter side of the packing.

Abstract: A trunnion-type ball valve, a valve seal structure, and a valve packing in which, a seal surface pressure of a tip outer peripheral region is improved. A ball (3) provided inside a body (2) is rotatably provided via upper and lower stems (4 and 5) and is sealed with a ball seat (6). The trunnion-type ball valve has a packing attached between an outer periphery step part provided at a rear part of the ball seat and the body and a pressing mechanism by which the packing is pressed to a ball direction, and is provided with a contact surface to be contacted with a step part surface of the outer periphery step part on a tip outer diameter side of the packing and a space provided between the packing and the step part surface of the outer periphery step part on a tip inner diameter side of the packing.

Abstract: A trunnion-type ball valve including a seat retainer (14) attaching a ball seat(s) to at least one side of a ball (12) having a through hole (12a) provided in a body (11). The ball is turnably provided via a stem (13), and the ball seat is attached in a protrusion-prevented and free state in an attachment groove formed in the seat retainer. An excessive pressure due to an abnormal pressure rise in a cavity upon full close or upon full open is configured to be relieved into a flow channel via a communication part provided between an inner peripheral surface of the ball seat and the attachment groove by moving the seat retainer in a direction opposite to the ball by self-tension utilizing the pressure and pushing-out the ball seat to a ball-side by the excessive pressure flowed into a rear-surface side of the ball seat in the attachment groove.

Abstract: A trunnion-type ball valve including a seat retainer (14) attaching a ball seat(s) to at least one side of a ball (12) having a through hole (12a) provided in a body (11). The ball is turnably provided via a stem (13), and the ball seat is attached in a protrusion-prevented and free state in an attachment groove formed in the seat retainer. An excessive pressure due to an abnormal pressure rise in a cavity upon full close or upon full open is configured to be relieved into a flow channel via a communication part provided between an inner peripheral surface of the ball seat and the attachment groove by moving the seat retainer in a direction opposite to the ball by self-tension utilizing the pressure and pushing-out the ball seat to a ball-side by the excessive pressure flowed into a rear-surface side of the ball seat in the attachment groove.