Selection of valve according to flow characteristics
Valve opening and closing and flow channel shape make the valve has a certain flow characteristics. When selecting a valve, we must take this into account.
1. The cut-off and connected media valves
Often choose a smaller flow resistance, the flow path is straight-through valves. Such valves have valve, closing valves, piston valve,down closed valve, due to the tortuous flow path, flow resistance than other valves, it is less preferred. However, allowing a higher flow resistance of the occasion, it can also be used closed valve.
2. The flow controlled valves
Often choose easily adjustable flow valve. The regulating valve, throttle valve, piston valve, because the relationship between stroke proportional to its size and the opening and closing the valve seat member. Rotary (such as plug valves, ball valves, butterfly valves) and flexural body type (pinch valve, diaphragm valve) valve throttle control can also be used, but usually within a limited scope of application of the valve diameter only. In most cases, people usually change the shape of the valve shut-off valve made after throttling. It should be noted, by varying the opening height gate or globe valves to achieve the throttle effect is extremely unreasonable. Because the media in the pipeline in the throttle state, the flow rate is high, seal face wear susceptible to erosion, loss of seal cutting, empathy with the throttle as the cutting device is unreasonable.
3. Commutation shunt valves
According to the commutation shunt required, this valve has three or more channels, the choice of suitable plug and ball valves. Most commutation shunt valves are used in the selection of these valves. In some cases, other types of valves, only with two or more appropriately connected to each other, can also be used to change the media diversion.
4. Medium with suspended particles valves
If the media with suspended particles, the most suitable use of valve opening and closing parts which slide along the sealing surface with a wiping action. Such as flat gate.