How is flow orifice size calculated?

Divide the flow of the liquid by the velocity of the liquid to determine the area of the orifice in square feet. In the above example, you would divide 8 by 2. The total area of the orifice would be 4 square feet.

What does Venturi flowmeter measure?

A venturi works by measuring the difference in pressure at two different locations. The pressure difference is created by reducing the diameter of the pipe causing the fluid to flow faster. The fast moving fluid has a lower pressure than the slower fluid in the larger section of the venturi.

How is Venturi meter flow rate calculated?

The venturi meter device measures the flow rate or velocity of a fluid through a pipe. The equation is based on the Bernoulli equation, conservation of energy, and the continuity equation….Change Equation.

Q = flow rate
A2 = Area 2
P1 = Pressure 1
P2 = Pressure 2
rho = density

How do I know what size Venturimeter I need?

Cylindrical Throat: Throat consists of the minimum venturemeter diameter. In the throat section, the velocity is maximum and pressure is minimum. Normally, throat diameter = 1/3 to 1/4th of inlet pipe diameter. Diverging Conical section: At this section of venturimeter, the tube diameter gradually increases.

What is the orifice size for propane?

0.010 to 0.016′
Propane (LP) orifice sizes typically vary from 0.010 to 0.016′′ diameter, but 0.010′′ appears common, for which energy con- sumption is 548 Btu/hr at a typical 11′′ pressure.

How accurate is a Venturi meter?

Note that by default, Venturi flow meters offer an accuracy of around ±1% of the discharge coefficient. Optimum calibration allows an even greater accuracy of up to ±0.25%. Venturi nozzle flow rate measurement systems are marginally more expensive than orifice-style flow meter systems.

What is the use of Venturi Metre?

A venturi meter is also called a venturi flowmeter. It is used to calculate the velocity of fluids in running through a pipeline. The fluid may be a liquid or a gas. The meter consists of a pipe with a narrowing throat that expands back to it’s original diameter on the other side of the choke point.

What is the principle of Venturi meter?

The principle of venturimeter is that when a fluid flows through the venturimeter, it accelerates in the convergent section and decelerates in the divergent section, resulting in a drop in the static pressure followed by a pressure recovery in the flow direction.

What is the disadvantage of Venturi tube?

Disadvantages of venturi meter: They are large in size and, therefore, where space is limited, they can not be used. Initial costs, installation and expensive maintenance. Requires a long placement length.

What is the basic principle of Venturi meter?

The principle behind the operation of the Venturi flowmeter is the Bernoulli effect. The Venturi measures a fluid’s flowrate by reducing the cross sectional flow area in the flow path and generating a pressure difference.

How big does a venturi flow meter need to be?

Venturi flow meters offer high accuracy and reliability for flow measurement of pressurized line fluids, including liquids, gases, and steam, as well as high-viscosity line fluids, solids-bearing line fluids, and harsh or contaminated line fluids. Line Size: 1/2 to 144 inches. Line size: 4 to 96 inches.

How are flow nozzles different from Venturi tubes?

The differences compared with the Venturi tubes include: 1. Flow nozzles are suitable for circular cross section only. 2. Flow nozzles are also designed with a converging-diverging profile but any straight portion in between is not required. Flow nozzles are used to determine the flowrate of the fluid through pipes with these three different types:

How are pressure and temperature measured in a venturi?

The Venturi Principle. A Venturi requires two pressure and one temperature measurement to accurately determine flow. The first pressure is measured at the Venturi’s upstream location, P1. This is used for the density calculation and the high side input to the differential pressure measurement.

Where does the liquid come from in a venturi tube?

A tank, open at the top, with liquid emerging from an orifice located a vertical height h below the surface of the liquid. Both sides of Equation (9-36) include atmospheric pressure because the pressures appearing in Bernoulli’s equation are absolute pressures. Solving Equation (9-36) for ν gives