How do you measure natural gas flow?

Natural gas flow is primarily measured using various technologies, with orifice meters being among the most common.

Common Technologies for Measuring Natural Gas Flow

Several technologies exist for accurately measuring the flow rate of natural gas. Each method has its own advantages and disadvantages, making them suitable for different applications and conditions.

• Orifice Meters:

  • One of the oldest and most widely used methods.
  • Works by introducing a restriction (the orifice plate) into the pipeline.
  • Measures the pressure drop across the orifice plate.
  • The flow rate is calculated based on the pressure drop and the characteristics of the gas.
  • Relatively inexpensive and simple to install and maintain.
  • Can be less accurate than other methods, especially at low flow rates.

• Turbine Meters:

  • Use a turbine rotor that spins as gas flows through it.
  • The rotational speed of the turbine is proportional to the flow rate.
  • Highly accurate and reliable for a wide range of flow rates.
  • Suitable for custody transfer applications.
  • Require regular maintenance and calibration.

• Ultrasonic Meters:

  • Use sound waves to measure the velocity of the gas.
  • Highly accurate and reliable.
  • Non-intrusive, meaning they don't obstruct the flow of gas.
  • Can measure flow in both directions.
  • More expensive than other types of meters.

• Coriolis Meters:

  • Measure the mass flow rate of the gas directly.
  • Highly accurate and can handle a wide range of gas compositions and conditions.
  • Unaffected by changes in temperature, pressure, or density.
  • Expensive and complex to install and maintain.

• Thermal Mass Flow Meters:

  • Measure the heat required to maintain a constant temperature difference between two sensors.
  • The amount of heat required is proportional to the mass flow rate of the gas.
  • Suitable for low flow rates and clean gas applications.
  • Sensitive to changes in gas composition and temperature.

Factors Influencing Meter Selection

The selection of the appropriate meter depends on various factors, including:

• Accuracy requirements
• Flow rate range
• Gas composition and conditions
• Cost
• Maintenance requirements

In summary, natural gas flow is measured using a variety of technologies including orifice, turbine, ultrasonic, Coriolis, and thermal mass flow meters, each offering a unique balance of accuracy, cost, and suitability for different applications.