orificemeter

An orificemeter is a flow measurement device that determines volumetric or mass flow rate of fluids by creating a restriction in a pipe using an orifice plate. The plate is a thin plate with a precisely sized circular opening. As fluid passes through the opening, its velocity increases and a pressure drop occurs across the plate, which is measured to calculate flow using Bernoulli’s equation and a discharge coefficient.

The instrument typically comprises a mounting flange for the orifice plate, differential pressure transducers connected to a pressure gauge or digital meter, and a calibration chart or electronic control unit. Some modern systems integrate analog readouts with wireless data transmission for remote monitoring.

Orificemeters are common in chemical processing, petroleum refining, water treatment, and HVAC systems where accurate flow measurement of liquids or gases is required. They are favored for their simplicity, low cost, and ability to handle a wide range of flow rates. However they are sensitive to upstream and downstream pressure changes, surface roughness, and the Reynolds number, which affects the discharge coefficient.

Industry standards governing orificemeter design and calibration include ISO 5167 for pressure-based flow meters, ASTM D5160 for water meters, and DIN 5077 for gas meters. Maintenance typically involves periodic inspection for plate damage, cleaning of flow passages to prevent fouling, and re‑calibration of pressure sensors to maintain accuracy.

When properly installed and calibrated, an orificemeter provides a robust, reliable means of measuring flow that balances performance with low operational complexity, making it a staple in many industrial and municipal fluid management systems.