Patent attributes
A movable member is fitted in the middle in the vertical direction of a valve body core fitting that forms a gate valve body, and the movable member presses an elastic seal member from the inside of the seal member toward a tube inner wall surface located in a direction crossing the direction of insertion of the seal member. The movable member has arms and contact sections. The arms each have a second inclined section for pressing the elastic seal member against the tube inner wall surface upon receiving pressing action from a first inclined section that is formed on a pressing member and changes the direction of pressing. The contact sections are in contact with and press the inside of the elastic seal member. The contact sections of the movable member have recesses having inside the elastic seal member.