Orifice (Differential Pressure) Flow meter Design 2

Orifice plates are really hard to install. To get a good velocity profile, the mechanical specification for meter tube, the orifice flanges or fitting the differential pressure sensing taps, the upstream and downstream piping requirements must be adhere to the standard. But don’t worry, velocity profiles are only pretty pictures in engineering textbooks

Orifice Plates and holders

Orifice plates are usually installed between special flanges in a horizontal pipe run. The flanges are thicker than normal to accommodate two small bore tapings for connection to a DP cell. The plate is positioned concentrically within the flange bolt circle with the tap protruding near the top of flanges. The tab has a hole and the orifice plates must have information engraved to indicate the correct upstream / downstream orientation.

Control Valve Operation and Design Criteria for Beginners 1

Control valves are used throughout the process to control pressure, level, temperature, or flow. All control valves have variable opening or orifice. For a given pressure drop across the valve, the larger the orifice the greater the flow through the valve.

















Fig 1: Typical single-port body control valve (courtesy of Fisher)