1, the classification according to mechanical movement
Some users will be classified according to the valve mechanical movement. Linear motion valve (also known as a straight line valve), which has a sliding stem to drive a closed element to open the closed position (closed element is the internal valve device used to open, close or adjust the flow). Gate valve, globe valve, hose valve, sanitary diaphragm valve, open body valve, three-way valve, angle valve, etc.. Because of the simple design, easy maintenance and more than the other classification of the movement of the valve has more size, pressure rating and design options, so they are the most common type of valve.
On the other hand, a rotary motion valve (also known as a rotary valve) is used to open or block the flow passage in the 1/4 angle or 45 DEG by a closing element. Rotary valves are generally smaller and lighter than their similar linear valves. They are restricted to work under certain pressure and are prone to cavitation and flash. But the design of the rotary valve has matured, they have overcome these limitations, is now being accelerated application.
2, according to the valve opening size classification
Full open valve
In the process system, most valves are designed to limit the flow to a certain range by closing the flow path or area of the closed element to less than the inner diameter of the pipe. On the other hand, some gate valves or sanitary ball valves can be designed as an internal flow channel with sufficient size to allow the passage of the flow without obvious limitations. This valve is called a fully open valve because its internal flow is equal to the total area of the inlet.
Fully open valve is mainly used for open and closed circuit. Fully open the valve also allows the use of "pig" in the pipeline, "pig" is a self driven (or flow driven) mechanism to purify the pipeline interior and remove any process aggregation or rust.
On the other hand, the mouth of the valve is closed component flow control valve. The flow area of the opening of the closed element is less than the area of the inner diameter of the pipeline. For example, the linear stop valve seat or plug valve with the valve inlet and outlet diameter of the same flow area. When the utility model is used, the pressure drop can be generated when the fluid flows through the closing element, so that the pressure can be restored after the flow through the throttling area.
The main purpose of the valve is to reduce the flow or through the throttle to control the flow, it is equivalent to regulate the closure of the valve to open the valve to provide a different amount of logistics.