Nuclear power gate valve - part 2
There are four main types of nuclear gate valves; they are wedge-type elastic single gate valve, wedge type double gate valve, parallel double gate valve with spring preload and parallel double gate valve with top block. The diameter DN of the gate valve in NI is generally above 80 mm. The valve body of the nuclear gate valve must be forged. Only the gate valve body of the core 2 or core 3 is allowed to use castings. However, because the quality of the casting is difficult to control and guarantee, it often use forgings.
The wedge type elastic single gate valve has the characteristics of simple sealing structure, firmness and reliability, but the manufacturing angle requires that the sealing angle of the sealing surface of the gate and the valve body is strict, and the main circuit system is used more .
The wedge type double gate valve structure is a conventional structural form of a thermal power station. Since the angle of the wedge-shaped double plate can be adjusted by itself, the sealing is relatively reliable and the maintenance is convenient.
The parallel double-gate gate valve with spring preload has the advantage that the load will not increase sharply when the shutter is closed, but at the same time it will bring spring force so that the gate will not disengage the valve seat when opening and closing , and the sealing surface is relatively worn. It is large, and at the same time, there are many sealing parts and parts, and the assembly is inconvenient.
The parallel double-gate gate valve with the top block is opened by the top block to make the two gates staggered along the inclined surface to close the gate valve, and the sealing is relatively reliable, but there are also problems of many sealing parts of the gate.
The wedge type elastic single gate valve has the characteristics of simple sealing structure, firmness and reliability, but the manufacturing angle requires that the sealing angle of the sealing surface of the gate and the valve body is strict, and the main circuit system is used more .
The wedge type double gate valve structure is a conventional structural form of a thermal power station. Since the angle of the wedge-shaped double plate can be adjusted by itself, the sealing is relatively reliable and the maintenance is convenient.
The parallel double-gate gate valve with spring preload has the advantage that the load will not increase sharply when the shutter is closed, but at the same time it will bring spring force so that the gate will not disengage the valve seat when opening and closing , and the sealing surface is relatively worn. It is large, and at the same time, there are many sealing parts and parts, and the assembly is inconvenient.
The parallel double-gate gate valve with the top block is opened by the top block to make the two gates staggered along the inclined surface to close the gate valve, and the sealing is relatively reliable, but there are also problems of many sealing parts of the gate.