| 摘要 |
The invention relates to valves and particularly, though not exclusively, to gate valves. There is provided a valve comprising a housing (1) and a valve member (2) moveable within the housing (1) to open and close the valve. In a first aspect the valve is provided with means to reduce friction between the housing (1) and valve member (2). In a second aspect the valve is provided with an operating member (20) which is associated with the valve member (2) and passes through an aperture (21) in the housing (1) which is sealed when the valve is in the open position. Such a valve addresses difficulties relating to the operation of prior art valves, particularly gate valves, and specifically the difficulties created by frictional drag upon movement of the valve member, and difficulties in maintaining the valve. |
