What makes a control valve become linear equal percentage or quick opening control valve?
Linear valves are used in most applications except heat transfer (temperature control). Non-Linear Valves: If the valve gain rises as the valve opens, its characteristic is called equal percentage (=%) and if its gain drops as it opens, it is called quick-opening (QO).
How do you calculate the flow rate of a valve CV?
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.
How does CV affect flow?
The definition of Cv is based on water, which has a G (specific gravity) = 1.0. Fluids with other gravities will flow at different rates. For example, heavier fluids will have a greater pressure loss through the same valve passage. The viscosity of the fluid will also affect its flow rate through a valve.
What is difference between SCFM and CFM?
The full form of CFM is Cubic Feet per Minute whereas the full form of SCFM is Standard Cubic Feet per Minute. CFM is always a smaller number than SCFM as it is calculated at higher pressure than the SCFM which makes the air volume smaller.
What is CV factor?
The Cv factor is the number of U.S. gallons per minute that will pass through a valve with a pressure drop of (1) psi.
How do you calculate CV of gas?
Inlet Pressure 32 kgf / cm2 Convert to absolute pressure = 33.03 kgf / cm2 (A). Outlet Pressure 15 kgf / cm2 convert to absolute pressure = 16.03 kgf / cm2 (A). Because the fluid is a gas and ΔP ≥ P1 / 2 so we will use the formula. Cv = (48000 / (248 × 33.03)) x sqrt (0.86 x (273 240)).
What is CV and CP?
So, Cp represents the molar heat capacity, C when pressure is constant. In other words, Cv is the heat energy transfer between a system and its surrounding without any change in the volume of that system. Cv represents the molar heat capacity C when volume is constant.
What is the ratio of CP and CV?
The Cp/Cv ratio is also called the heat capacity ratio. In thermodynamics, the heat capacity ratio is known as the adiabatic index. (i.e.) Heat Capacity ratio = Cp/Cv = Heat capacity at constant pressure/ Heat capacity at constant volume.
Which is greater CP or CV?
cp is greater than CV because when gas is heated at constant volume,whole of the heat supplied is used to increase the temperature only. But when gas is heated at constant pressure,the heat supplied is used to increase both temperature and volume of gas./span>
What is CP for water?
Specific Heat of Water For liquid at room temperature and pressure, the value of specific heat capacity (Cp) is approximately 4.2 J/g°C. This implies that it takes 4.2 joules of energy to raise 1 gram of water by 1 degree Celsius. This value for Cp is actually quite large.
Does Steam have a higher specific heat than water?
Steam at 100°C contains more heat than water at 100°C. Specific heat is amount of heat required to change temperature of one kg of substance by one degree Celsius. Latent heat is amount of heat required to change state of substance without increase in temperature.
What is the difference between CP and CV in thermodynamics?
CV: CV is the amount of heat energy that a substance absorbs or releases (per unit mass) with the change in temperature where a volume change does not occur. CP: CP is the amount of heat energy that a substance absorbs or release (per unit mass) with the change in temperature where a pressure change does not occur./span>
Does CV change with temperature?
At ordinary temperatures, CV and CP increase only slowly as temperature increases. For many purposes they can be taken to be constant over rather wide temperature ranges. For real substances, CV is a weak function of volume, and CP is a weak function of pressure./span>
What is CP in enthalpy?
The specific heat capacity cp is called the specific heat at constant pressure and is related to the universal gas constant of the equation of state. This final equation is used to determine values of specific enthalpy for a given temperature. Across shock waves, the total enthalpy of the gas remains a constant.