Orifice Meter

Principle:

• Orifice Meter Based on Bernoulli's theorem and the continuity equation.

• When fluid passes through an orifice plate, the velocity increases, and pressure decreases.

• The pressure drop is related to the flow rate.

Formula:

Where:

• Q = flow rate

• Cd = discharge coefficient

• Ao = area of the orifice

• ΔP = pressure difference across the orifice

• ρ = fluid density

Construction:

1. Orifice Plate: A thin plate with a precisely machined hole.

2. Pressure Taps: Installed before and after the orifice plate to measure the pressure difference.
   

Differential Pressure Instrument

Working:

• Fluid flows through the orifice plate, causing a drop in pressure.

• The pressure difference is measured and used to calculate the flow rate.

Uses:

• Widely used in water, gas, and steam flow measurement in pipelines.

• Common in industries like oil and gas, chemical processing, and water treatment.

Advantages:

• Simple and inexpensive design.

• Easy to install and maintain.

• Suitable for a wide range of fluids.

Disadvantages:

• Causes significant permanent pressure loss.

• Accuracy affected by wear and tear of the orifice plate.

• Limited to certain flow conditions and ranges.