Also known as a differential pressure flow meter, it consists of aprimary sensing element (throttling element) and secondarydevices (differential pressure transmitter and flow display instrument), and is widely used for measuring the flow rate of gases,steam, and liquids. It features simple structure, convenient maintenance, stable performance, and reliable operation.
■ Employs imported single-crystal silicon intelligent differential pressure sensor
■ High precision, comprehensive self-diagnostic function
■ Intelligent orifice plate flowmeter with self-programmable flow range
■ Simultaneously displays cumulative flow, instantaneous flow, pressure, and temperature.
■ Features online and dynamic full compensation functions, as well as self-diagnosis and self-setting flow range.
■ Equipped with multiple communication interfaces
■ High stability
■ Wide flow range, greater than 10:1
High-range differential pressure flow devices, composed of a standard orifice plate and a multi-parameter differential pressure transmitter (or differential pressure transmitter, temperature transmitter, and pressure transmitter), are widely used in the production processes of industries such as metallurgy, power, chemical, pharmaceutical, food, military, scientific research, water supply, and heating for the measurement, control, and regulation of fluid (liquid, gas, steam)flow.
WORKING PRINCIPLEAn orifice plate flow meter is a differential pressure flow meter and is the most widely used type of flow meter. It is a high-range differential pressure flow device composed of a standard orifice plate and a multi-parameter differential pressure transmitter (or differential pressure transmitter, temperature transmitter, and pressure transmitter) to measure the flow rate of gases, steam, liquids, etc.
The orifice plate flow meter is based on Bernoulli's equation and the flow continuity equation. When fluid flows through a throttling element, a differential pressure is generated on both sides, and this differential pressure isproportional to the square of the flow rate.
The orifice plate flow meter is one of the most widely available standard throttling devices. It is the simplest in structure and the most adaptable among throttling devices, widely used in the measurement of various fluids, especially gases. Its design, manufacture, and use comply with the international standard ISO 5167 and are verified according to the national standard JG640-2016.
TECHNICAL PARAMETERS
| Measuring medium | Liquids, gases, and vapors | |
| Ambient temperature | -20 to 70℃ | |
| Ambient humidity | 0-100% relative humidity | |
| Measuring medium temperature | -40 to 400℃ | |
| Measuring medium pressure | 1.6-40MPa | |
| Product operating power supply voltage | AC220V | |
| Output signal type | 4-20mA | 0~Qmax |
| Product accuracy class | 1.0-2.5 class | |
| Storage temperature | -40 to 85℃ |
Reference operating condition flow range
| CALIBER | LIQUID FLOW RATE RANGE (M³/H) | GAS FLOW RATE RANGE (M³/H) |
| DN50 | 5~21 | 70-300 |
| DN65 | 7~30 | 100-400 |
| DN80 | 12~50 | 150-600 |
| DN100 | 15~62 | 230-900 |
| DN125 | 42~180 | 360-1500 |
| DN150 | 55~230 | 500-2000 |
| DN200 | 80~340 | 900-3600 |
| DN250 | 90~400 | 1400-5600 |
| DN300 | 115~460 | 2000-8000 |
PRODUCT STRUCTURE STANDARDS
Standard orifice plates can be classified into three types according to their pressure tapping method: corner tapping (including annular chamber tapping and individual borehole tapping), flange tapping, and radial tapping.
In our products, we use the flange tapping type. Flange tapping offers advantages over corner tapping, such as simpler assembly, easier installation, and easier removal of contaminated media from the tapping port. It is widely used in the petroleum, chemical, and other industries for flow measurement, control, and regulation of various media.
Flange pressure tapping structure diagram:
The orifice plate flowmeter itself consists of a high-precision differential pressure transmitter, a three-valve manifold, pressure taps, flanges, and a throttling element. During operation, the two end valves of the three-valve manifold are open, while the middle valve is closed. The medium flow direction must follow the direction indicated by the instrument and cannot be reversed. Its composition is shown in the diagram below.
ON-SITE INSTALLATION
The accuracy of an orifice plate flow meter largely depends on the correct installation of the transmitter and pressure taps. Proper installation of the primary measuring element is crucial for accurate flow measurement.
Due to process flow and economic factors, flow meters are often installed in harsh environments. However, flow meters should ideally be installed in locations with minimal temperature gradients and fluctuations, while avoiding vibration and shock.
Installation requirements for piping:
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| (The following diagram shows the pipe length requirements for instrument installation) |
| Upstream of the sensor Pipe type | Length of front and rear straight pipe sections | Upstream of the sensor Pipe type | Length of front and rear straight pipe sections |
| Concentric contraction fully open valve |  |
A 90° bend |  |
| Two 90°bends on the same plane |  |
Two 90°bends on different planes |  |
| Concentric expansion tube |  |
Control valve partially open. (Not recommended) |  |
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COMMON FAULTS AND TROUBLESHOOTING
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The piping connecting the flow meter to the measured medium transmits the pressure from the pressure tap to the transmitter. Potential causes of error during pressure transmission include: |
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The following methods can reduce errors: |
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