What is discharge coefficient valve?
Discharge Coefficient. The discharge coefficient is a characteristic non-dimensional factor of the valve, which is used to calculate the flow rate (Q) when the valve discharges the fluid from a tank or reservoir (Δh) to the environment. (liquids)
What is the Cv of a globe valve?
Cv is the volume of water in U.S. gallons per minute that passes through the valve at a pressure drop of 1 PSI at 68°F.
What is the Cv value of a valve?
What is Cv value? The valve flow coefficient according to the JIS standard, represents the flow capacity in US gallons/minute of 60° F pure water when it is flowing through the valve with a pressure difference of 1 psi at the specified travel (operation range).
How do you calculate discharge coefficient?
To calculate discharge coefficient:
- Multiply the hydraulic head by the acceleration due to gravity.
- Multiply the resultant by 2 .
- Find the square root of the product.
- Multiply the resulting value by the area of cross-section to obtain the theoretical discharge for a fluid flow.
What is the relation between CD Cv and CC?
Coefficient of discharge (Cd) = Coeff. of flow/velocity (Cv) x Coeff of contraction (Cc). If you know coeff. of flow/velocity (Cv) , you will be able to calculate coeff of discharge (Cd), once Cc is known.
How do you calculate flow rate on Cv?
The flow rate value can be determined using a formula; the larger the value, the higher the flow rate will be through the valve at a given pressure drop….Defined as:
- The flow rate in U.S. gallons per minute (gpm) of water.
- At a temperature of 60° Fahrenheit.
- With a pressure drop across the valve of 1 psi.
How do you calculate the flow coefficient of a valve?
The equation for calculating the valve flow coefficient is Cv = Q √ (SQ/P). Now that we’ve ascertained the values for our variables, we can plug them into the equation. Once we do that, our example should look like this: Cv = 10 √ (1/0.11).
What is the range of coefficient of discharge?
The orifice discharge coefficients are in the range of 0.6-0.9 and are affected by the fluid viscosity and the size of the vena contracta in the orifice.
How is the velocity coefficient Cv the discharge?
Coefficient of Velocity(Cv) is defined as the ratio between the actual velocity of a jet of liquid at vena-contracta and the theoretical velocity of the jet. Co-efficient of contraction(Cc) is defined as the ratio of the area of the jet at vena-contracta to the area of the orifice.
How do you convert Cv to flow rate?
The volume flow rate for liquids can be calculated by multiplying the fluid velocity times the flow area. Thus, Cv is numerically equal to the number of U.S. gallons of water at 60°F that will flow through the valve in one minute when the pressure differential across the valve is one pound per square inch.
What is a good CV value?
CVs of 5% or less generally give us a feeling of good method performance, whereas CVs of 10% and higher sound bad. However, you should look carefully at the mean value before judging a CV. At very low concentrations, the CV may be high and at high concentrations the CV may be low.