The relation between Valve Size and Medium Flow Velocity

The relation between Valve Size and Medium Flow Velocity


​1. The flow rate and flow velocity of the valve mainly depend on the diameter of the valve and the resistance of the structure of the valve to the medium. At the same time, they are intrinsically related to the pressure, temperature and concentration of the medium in the valve

2. The flow area of the valve is directly related to the flow rate and flow velocity, while the flow rate and flow velocity are two interdependent quantities. When the flow rate is constant, the area of the runner will be smaller if the flow rate is large, and the area of the runner will be larger if the flow rate is small. On the contrary, the area of the runner is large and its velocity is small, while the area of the runner is small and its velocity is large. 

3. If the flow rate of medium is high, the valve diameter can be small, but the resistance loss is large, hence it is easy to damage the valve. High flow rate will produce electrostatic effect on flammable and explosive media, causing danger; if the flow rate is low, the working efficiency will be low and make it uneconomical. For medium with high viscosity and explosive property, a smaller flow rate should be adopted. For oil and liquids with high viscosity, please choose the right flow rate with the degree of viscosity, generally 0.1-2 m/s. 

4. In general, the flow rate is known and the flow rate can be determined by experience. The nominal diameter of the valve can be calculated by flow rate and flow velocity. 

5. Valves with the same diameter may have different configurations and fluid resistance. Under the same conditions, the greater the resistance coefficient of the valve, the more the flow rate and flow velocity of the fluid through the valve decrease; the smaller the resistance coefficient of the valve, the less the flow rate and flow velocity of the fluid through the valve decrease. 

The relation between Valve Size and Medium Flow Velocity