Orifice Plate vs Venturi Meter

Orifice Plate vs Venturi Meter:

Both Orifice Plates and Venturi Meters are differential pressure flow measurement devices that operate on Bernoulli’s Principle. When fluid passes through a restriction, velocity increases and pressure decreases. By measuring this pressure difference, the flow rate can be accurately calculated.

Orifice Plate Working Principle

A thin metal plate with a precisely machined hole is installed inside the pipeline.

As fluid passes through the orifice, velocity increases sharply.

Pressure drops across the plate.

A Differential Pressure (DP) Transmitter measures the pressure difference between upstream and downstream taps.

The measured differential pressure is used to calculate flow rate.

Simple Design

Low Initial Cost

Easy Installation

High Permanent Pressure Loss

Lower Accuracy

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Venturi Meter Working Principle

Fluid enters a smoothly converging section.

Velocity gradually increases as the flow approaches the throat.

Pressure decreases at the throat section.

A DP Transmitter measures pressure difference between the inlet and throat.

The flow rate is calculated using the differential pressure.

High Accuracy

Very Low Pressure Loss

Excellent Repeatability

Suitable for Large Flow Rates

Higher Cost

Larger Installation Space Required

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Orifice Plate vs Venturi Meter

Accuracy

• Orifice Plate: Moderate

• Venturi Meter: High

Pressure Loss

• Orifice Plate: High

• Venturi Meter: Low

Cost

• Orifice Plate: Low

• Venturi Meter: High

Maintenance

• Orifice Plate: Easy

• Venturi Meter: Minimal

Installation

• Orifice Plate: Compact

• Venturi Meter: Requires Longer Straight Run

Best For

• Orifice Plate: Cost-sensitive applications

• Venturi Meter: High-accuracy flow measurement

Common Applications

Water & Wastewater Systems

Oil & Gas Industry

Chemical Processing Plants

Steam Flow Measurement

Power Plants & Boiler Systems

HVAC & Energy Management Systems

Engineering Insight

If low cost and simple installation are your priorities, an Orifice Plate is often the preferred choice. However, when long-term accuracy, energy savings, and low pressure loss are critical, a Venturi Meter provides superior performance despite its higher initial investment.