Threaded plug-in hydraulic relief valve LADRV-10

characteristic

The so-called small flow control valve, as its name implies, is a control valve with small circulation capacity.

The flow capacity of the valve is the valve capacity index under unified conditions. China is represented by C value. It is defined as: when the valve is fully opened, when the pressure difference before and after the valve is 1kg/cm2 and the medium weight is 1g/cm3, the medium mass (m3/hr) flowing through the valve every hour. For incompressible fluid, under the condition of full turbulence (when Reynolds number is large enough, Re > 10 5 for water; Re > 5.5× 104 for air)

Where:

△ p-pressure difference before and after the valve (kg/cm2) υ-medium severity (g/cm3)

Q-Media flow (m3/h)

The United States and other countries use the value of c to indicate the flow capacity of the valve. Internationally recognized I, E and C standards mainly related to electricity use Av value to indicate the flow capacity of valves. The conversion relationship among them is as follows:

Cv =1 ．17 C Cv =10 6 /24Av C=10 6 /28Av

The flow capacity of the valve only depends on the structure of the valve itself. When calculating the required valve flow capacity, it should be noted that the flow state in the valve will be very different when the medium is different or the flow conditions are different.

In the case of small flow rate, especially viscous fluid and low pressure, the main constraint of fluid is often laminar or mixed state of laminar and turbulent flow. In laminar flow, there is a linear relationship between the medium flow through the valve and the pressure difference before and after the valve. In the mixed state of laminar flow and turbulent flow, with the increase of Reynolds number, even if the pressure difference is constant, the dielectric mass flowing through the valve will increase. In complete turbulence, the flow rate does not change with Reynolds number. Nevertheless, the selection of small flow regulating valve is still carried out by traditional methods and calculation formulas. However, the calculated value deviates greatly from the actual value. According to the data, when CV is below Cv=0.01, it is only used as a capacity index and has reference significance. The actual circulation capacity should be determined according to