What is Orifice Tapping?

Orifice tapping is a process used to measure the flow rate of fluids in pipes, typically in industrial applications. It involves installing an orifice plate in the pipeline to create a restriction, which causes the fluid to accelerate as it passes through the plate. This acceleration results in a differential pressure across the orifice plate, which can be measured using pressure transducers.

The orifice plate has a small hole or "tapping" on either side of the plate, which is used to measure the differential pressure across the plate. One tapping is placed upstream of the orifice plate and the other tapping is placed downstream of the plate. The pressure difference between these two points is proportional to the square of the fluid flow rate, according to Bernoulli's principle.

The orifice tapping method is commonly used in industrial processes such as oil and gas production, chemical processing, and water treatment, where accurate flow measurement is essential for process control and optimization. It is a relatively simple and cost-effective method of flow measurement, but it does require careful calibration and maintenance to ensure accurate results.

Orifice Tap Location

The orifice plate in an orifice tapping setup is typically installed in a straight section of pipe, which should be long enough to ensure that the fluid flow is fully developed and stable before it reaches the plate. The recommended minimum straight pipe length upstream of the orifice plate is typically 10 pipe diameters, while the minimum downstream length is usually 5 pipe diameters.

The orifice plate should be installed with the sharp edge facing upstream, to ensure that the fluid flow is smoothly and evenly constricted as it passes through the plate. The two pressure taps, which are used to measure the differential pressure across the plate, are located on either side of the orifice plate. The upstream tap is typically located about one pipe diameter upstream of the orifice plate, while the downstream tap is typically located about one-half pipe diameter downstream of the plate.

The location of the pressure taps is critical to obtaining accurate flow measurements, and they should be carefully positioned and aligned to ensure that they accurately represent the pressure differential across the plate. The taps are typically connected to pressure transducers or gauges, which measure the differential pressure and provide an output signal proportional to the fluid flow rate.

Flange Taps

Flange taps are a type of pressure tap that is used to measure the pressure differential across an orifice plate or other type of flow meter. They are typically used in applications where it is difficult or impractical to install traditional pressure taps directly on the pipe, such as in large diameter pipelines or in pipes that are buried or insulated.

Flange taps are installed directly on the flanges of the pipe, using special hardware that allows for the installation of pressure taps on the flange without interfering with the sealing surfaces of the flange. The taps are typically located in the bolt holes of the flange, and are oriented so that they are perpendicular to the flow of fluid in the pipe.

The pressure taps are connected to pressure transducers or gauges, which measure the differential pressure across the orifice plate or other flow meter. The output signal from the pressure transducers can be used to calculate the flow rate of the fluid, based on the size and geometry of the orifice plate or other flow meter.

Flange taps have several advantages over traditional pressure taps, including their ease of installation and their ability to be installed on pipes that are difficult to access. However, they can be more expensive than traditional pressure taps and may require additional hardware to properly install and seal the pressure taps on the flange. Additionally, the orientation and placement of the pressure taps on the flange can affect the accuracy of the flow measurement, and must be carefully designed and installed to ensure accurate results.

Vena contracta taps

Vena contracta taps are a type of pressure tap that is used to measure the pressure differential across an orifice plate or other type of flow meter. They are located downstream of the orifice plate, where the fluid flow stream is constricted to its minimum cross-sectional area. At this point, the fluid velocity is highest and the pressure is lowest, creating a point of maximum differential pressure across the orifice plate.

Vena contracta taps are typically small diameter tubes or pipes that are inserted through the downstream face of the orifice plate and extend into the fluid stream at the point of maximum constriction. The pressure taps are located on either side of the vena contracta, and are connected to pressure transducers or gauges that measure the differential pressure across the orifice plate.

The advantage of using vena contracta taps is that they provide a more accurate measurement of the pressure differential across the orifice plate, since they are located at the point of maximum constriction where the fluid flow is most uniform and predictable. However, they can be more difficult to install and require a more precise measurement of the location of the vena contracta point, which can be affected by changes in fluid viscosity, density, and flow rate.

Overall, vena contracta taps are a valuable tool for accurately measuring the flow rate of fluids in a wide range of applications, including industrial processes, water and wastewater treatment, and energy production.

Corner taps

Corner taps are a type of pressure tap used to measure the pressure differential across an orifice plate or other type of flow meter. They are typically located at the corners of the pipe or duct where the orifice plate is installed. Corner taps are sometimes also referred to as flange taps, although the two terms are not always interchangeable.

Corner taps are installed by drilling or welding small pipes or tubes into the corners of the pipe or duct. These taps are then connected to pressure transducers or gauges, which measure the differential pressure across the orifice plate or other flow meter. The output signal from the pressure transducers can be used to calculate the flow rate of the fluid, based on the size and geometry of the orifice plate or other flow meter.

One of the main advantages of corner taps is that they are relatively easy to install and can be used in a wide range of pipe and duct sizes. They can also provide an accurate measurement of the pressure differential across the orifice plate if they are located and installed correctly. However, their accuracy can be affected by changes in the flow rate and viscosity of the fluid, as well as by the orientation and placement of the taps within the pipe or duct.

Overall, corner taps are a valuable tool for measuring the flow rate of fluids in a wide range of applications, including industrial processes, water and wastewater treatment, and energy production.

Orifice Plate Taps

Orifice plate taps are a type of pressure tap that is used to measure the pressure differential across an orifice plate, which is a common type of flow meter used to measure the flow rate of fluids in industrial processes, water treatment, and energy production applications.

Orifice plate taps typically consist of two small holes or ports drilled into the pipe or duct at a fixed distance upstream and downstream of the orifice plate. These taps are then connected to pressure transducers or gauges, which measure the differential pressure across the orifice plate. The output signal from the pressure transducers can then be used to calculate the flow rate of the fluid based on the size and geometry of the orifice plate.

One of the advantages of orifice plate taps is that they are relatively simple and easy to install, and can be used in a wide range of pipe and duct sizes. They are also relatively low cost and can provide accurate flow rate measurements if they are installed and calibrated correctly. However, their accuracy can be affected by changes in the fluid viscosity, density, and temperature, as well as by any irregularities or distortions in the flow profile upstream and downstream of the orifice plate.

Overall, orifice plate taps are a valuable tool for measuring the flow rate of fluids in a wide range of applications, and are often used in conjunction with other types of flow meters and instrumentation to provide a more comprehensive picture of fluid flow in industrial processes and other applications.

Orifice Plate with Flange Taps

Orifice plate with flange taps is a type of orifice plate installation that uses flanges to create the pressure taps necessary for measuring the differential pressure across the orifice plate. Flange taps are installed in the flanges of the pipe or duct, and are connected to pressure transducers or gauges that measure the differential pressure.

To install an orifice plate with flange taps, the flanges of the pipe or duct are modified to include small ports or holes that allow pressure to be measured upstream and downstream of the orifice plate. These ports are typically drilled or machined into the flanges and are designed to align with the orifice plate.

The pressure taps are then connected to pressure transducers or gauges, which measure the differential pressure across the orifice plate. The output signal from the pressure transducers can then be used to calculate the flow rate of the fluid based on the size and geometry of the orifice plate.

One of the advantages of using orifice plates with flange taps is that they are relatively easy to install and require minimal modifications to the existing piping or ductwork. They are also a cost-effective solution for measuring flow rates in a wide range of applications. However, like other types of orifice plate installations, their accuracy can be affected by changes in the fluid properties and the presence of irregularities in the flow profile upstream and downstream of the orifice plate.

Overall, orifice plate with flange taps is a popular choice for measuring the flow rate of fluids in a wide range of industrial processes, water and wastewater treatment, and energy production applications.

integral orifice plate

An integral orifice plate is a type of orifice plate that is fabricated directly into a pipeline or duct. It is typically made from the same material as the pipeline or duct and is designed to be a permanent part of the system.

The integral orifice plate consists of a thin plate that is inserted into the pipeline or duct and has a precisely sized orifice in the center. The orifice creates a pressure drop as the fluid passes through it, which can be measured to determine the flow rate of the fluid.

One of the main advantages of an integral orifice plate is that it provides a permanent flow measurement solution that requires minimal maintenance. It is also less prone to leaks or failures compared to other types of orifice plates, such as flange taps or corner taps.

However, the design and installation of an integral orifice plate requires a high level of expertise and precision. The plate must be precisely sized and positioned within the pipeline or duct to ensure accurate flow measurement. Additionally, the installation process can be time-consuming and expensive, particularly for large pipelines or ducts.

Overall, integral orifice plates are commonly used in applications where a permanent flow measurement solution is required and accuracy is critical. Examples of these applications include oil and gas pipelines, chemical processing plants, and power generation facilities.