Which is better venturi meter or orifice meter?
The pressure loss in venturi meter is 10% while in the orifice meter the pressure loss is 50-60%. The coefficient of discharge in the venturi meter is 0.98 while in orifice meter it is 0.6. The turn down ratio of venturi meter is 10:1 while in orifice meter it is 5:1.
What type of flow meter is orifice meter?
An Orifice Meter is basically a type of flow meter used to measure the rate of flow of Liquid or Gas, especially Steam, using the Differential Pressure Measurement principle. It is mainly used for robust applications as it is known for its durability and is very economical.
What does an orifice meter measure?
The orifice meter determines the flow through the difference in pressure between the upstream and the downstream side of a partly impeded pipe.
Why is a venturi meter better than orifice?
Compare Venturi and Orifice The orifice meter has a large permanent loss of pressure because of the presence of eddies on the downstream side of the orifice-plate; the shape of the venturi meter prevents the formation of these eddies and greatly reduces the permanent loss. The orifice is cheap and easy to install.
Why is Venturimeter more accurate than orifice meter?
Higher flow rates in high quality orifice plates gives increased accuracy. Venturimeters are widely used for high flow rates. They can handle 25-50% more flow rate than an orifice.
What are the advantages of orifice meter over Venturimeter?
Advantages of Orifice meter: The orifice meter can be easily maintained. Measures a wide range of flows. They have a simple construction. They have easily fitted between the flanges.
Where is an orifice used?
The orifice plate flow meter is a type of differential pressure flow meter that is commonly used in clean liquid, gas, and stream mass flow measurement.
What is the difference between Venturimeter and pitot tube?
The reason is that there is no stagnation point in a venturi meter, whereas there is one in a pitot meter. Both rely upon Bernoulli’s equation, but use different terms. The venturi meter takes advantage of a constriction to change the speed of fluid flow, thus changing the dynamic pressure.
Why is Venturimeter used?
A venturi meter is used to measure the flow speed of a fluid in a pipe. The meter is connected between two sections of the pipe ; the cross-sectional area A of the entrance and exit of the meter matches the pipes cross-sectional area.
Why orifice plate is used?
An orifice plate is a device used for measuring flow rate, for reducing pressure or for restricting flow (in the latter two cases it is often called a restriction plate ).
Can Venturimeter be used vertically?
Venturimeters can be installed in a horizontal, inclined, or vertical direction.
What is the limitation of orifice meter?
Disadvantages of orifice meter: It requires the flow of axial velocity vectors. It causes a pressure drop in the fluid. Its accuracy is affected by the density, pressure and viscosity of the fluid. The range of measurement of viscosity limits of fluids.
Why venturi is used?
Venturi are used to measure the speed of a fluid, by measuring the pressure changes from one point to another along the venture. A venturi can also be used to inject a liquid or a gas into another liquid.
How does orifice reduce pressure?
When a fluid (whether liquid or gaseous) passes through the orifice, its pressure builds up slightly upstream of the orifice but as the fluid is forced to converge to pass through the hole, the velocity increases and the fluid pressure decreases.
Why is a venturimeter more accurate than an orifice meter?
What is the difference between rotameter and orifice meter?
Rotameters. The orifice meter, Venturi tube and flow nozzle work on the principle of constant area variable pressure drop. Here the area of obstruction is constant, and the pressure drop changes with flow rate. On the other hand Rotameter works as a constant pressure drop variable area meter.
How does an orifice plate meter work?
Like all DP meters, the orifice plate meter cross-references the physical laws of conservation of mass and energy. The orifice provides the restriction to flow, while pressure taps on the upstream and downstream side of the restriction provide the necessary differential pressure.
What is the length of an orifice meter run?
Orifice meter runs require straight runs upstream and dowstream so that flow passing through it is laminar flow instead of turbulent flow. Most of the time, downstream straight length required is 5 times Diameter of the pipe. Upstream straight length requirement varies based on type of components immediately upstream of the orifice meter.
What is the coefficient of discharge C for an orifice meter?
Because of the sudden contraction at the orifice and the subsequent sudden expansion after the orifice, the coefficient of discharge C for the orifice meter is much lower than that of a venturi meter or a flow nozzle. In addition, depending on the pressure tap locations, section 1 and section 2, the value of C is different for orifices.
What types of provers are used with orifice meters?
Some operators are also beginning to use adaptations of them with orifice meters. Other provers may be master meters, critical flow provers, or a centralized proving facility where meters can be taken for accuracy confirmation.