Abstract: A gate valve including a valve disc which is moved to a position where the valve disc is brought into contact with a valve seat and a position where the valve disc is separated from the valve seat by a driving device provided outside of a valve housing through a valve rod sealingly projected from the inside to the outside of the valve housing. The valve disc is brought into contact under pressure with the valve seat in the valve housing when the valve rod is inclined at the end of the movement of the valve rod. The driving device has piston cylinder devices, a block arranged in side-by-side relationship with the piston cylinder devices and connected to the valve rod, and a device to move up and down and to incline the block. The device for moving the block may include a pivotable link or a pin received in an oblique hole in a sleeve.

Abstract: A gate valve wherein a valve disc is moved to a position where the valve disc is brought into contact with a valve seat and a position where the valve disc is separated from the valve seat by a driving device provided outside of a valve housing through a valve rod sealingly projected from the inside to the outside of the valve housing. The valve disc is brought into contact under pressure with the valve seat in the valve housing when the valve rod is inclined at the end of the movement of the valve rod. The driving device has piston cylinder devices, a block arranged in side-by-side relationship with the piston cylinder devices and connected to the valve rod, and a device to move up and down and to incline the block.

Abstract: A sealing device of this invention is designed to prevent entering of the open air through a coupling of a process tube of a CVD apparatus. The sealing device includes a first flange having a mirror-finished face, a second flange having a face which is brought into contact with the face of the first flange, at least one gas guide which is open to at least one of the faces of the first and second flanges and an evacuation system for evacuating a region, in which the first and second flanges are brought into contact with each other, through the gas guide.