Contact Platform Support
Help CenterOrifice Plate Flowmeter
Related Products
Orifice plate flowmeter is the most widely used and oldest differential pressure flowmeter. It measures the flow rate by installing a perforated throttling element (orifice plate) in the pipeline and utilizing the pressure difference generated when the fluid flows through the orifice plate.
Main Features
Simple structure and no moving parts: The core component is a fixed orifice plate, so the structure is very simple, with high reliability, long service life, and almost no need for maintenance.
High degree of standardization: Its design, manufacturing, and installation follow international standards (such as ISO 5167) and national standards (such as GB/T 2624). The accuracy can be guaranteed without actual flow calibration, and the technology is very mature.
Wide application range: It can be used to measure the flow rates of various media such as liquids, gases, and steam, especially suitable for large-diameter pipelines and high-temperature and high-pressure working conditions.
Low cost: Compared with other high-precision flowmeters, the manufacturing and installation costs of orifice plate flowmeters are lower.
Working Principle
The working principle of the orifice plate flowmeter is based on Bernoulli's equation and the principle of fluid continuity, and the core is the "throttling effect".
Generate pressure difference: When the fluid flows through the orifice plate in the pipeline, the passage suddenly narrows, causing the fluid velocity to increase and the static pressure to decrease. In this way, a pressure difference (ΔP) is formed between the upstream and downstream of the orifice plate.
Flow calculation: The magnitude of this pressure difference is proportional to the square of the fluid flow rate (velocity). The greater the flow rate, the greater the generated pressure difference. The differential pressure transmitter measures this pressure difference and converts it into an electrical signal, and then the instantaneous flow rate and cumulative flow rate are calculated through the flow integrator.
️ Precautions for Installation and Use
The measurement accuracy of the orifice plate flowmeter is very sensitive to the installation conditions, and the specifications must be strictly followed.
High requirements for straight pipe sections: This is the most critical installation condition. To ensure that the fluid velocity distribution is uniform before flowing through the orifice plate, a long straight pipe section upstream of the orifice plate is required to stabilize the flow field, and a certain length of straight pipe section downstream is also required to restore the flow field. Usually, a straight pipe section of at least 10 times the pipe diameter (10D) upstream and at least 5 times the pipe diameter (5D) downstream is required.
Do not install it in the wrong direction: The orifice plate has a directionality. Its opening is conical, and the sharp side (small opening) must face the fluid flow direction, and the flared side (large opening) is the outflow end.
Requirement for coaxiality: During installation, it is necessary to ensure that the axis of the orifice plate opening strictly coincides with the axis of the pipeline; otherwise, measurement errors will occur.
Filled pipeline: The medium to be measured must fill the entire process pipeline, and there should be no gas-liquid two-phase flow; otherwise, accurate measurement cannot be achieved.
Installation of pressure guiding tubes: Depending on the different measured media, the installation methods of pressure guiding tubes also vary to prevent gas, liquid, or dirt from entering the differential pressure transmitter and affecting the measurement accuracy.
Summary of Advantages and Disadvantages
Advantages
Simple structure, sturdy and durable, no moving parts, and low maintenance cost.
High degree of standardization, reliable data, and no need for separate calibration.
Widely applicable to various media and working conditions, especially suitable for large-diameter pipes, high-temperature, and high-pressure occasions.
Low initial cost and high cost-performance ratio.
Disadvantages
Large pressure loss: Due to the throttling effect, a large and irreversible pressure loss will occur when the fluid passes through the orifice plate, which will increase the energy consumption of the pump or fan.
Stringent installation requirements: High requirements for the length of the upstream and downstream straight pipe sections, and the on-site installation conditions are often difficult to meet, thus affecting the accuracy.
Limited measurement range: The turndown ratio is usually 10:1 or 15:1, which is not as wide as that of other types of flowmeters such as turbine flowmeters.
Accuracy is affected by multiple factors: The machining accuracy of the orifice plate, installation quality, cleanliness of the fluid, and changes in physical properties will all affect its measurement accuracy.
Send Inquiry to This Supplier
You May Also Like
-
Stainless Steel Electromagnetic FlowmeterUS$ 3650MOQ: 1 Unit -
Insertion Vortex FlowmeterUS$ 1800MOQ: 1 Unit
-
Intelligent Turbine Flow MeterUS$ 2250MOQ: 1 Unit
-
Intelligent Vortex FlowmeterUS$ 1050MOQ: 1 Unit
-
Electromagnetic FlowmeterUS$ 960MOQ: 1 Unit
-
SS304 Orifice Plate FlowmeterUS$ 201 - 5,000MOQ: 1 Set
-
Orifice Plate FlowmeterUS$ 3400MOQ: 1 Set
-
Standard Orifice Plate FlowmeterUS$ 180 - 3,200MOQ: 1 Set
-
Steam Orifice Plate FlowmeterUS$ 50 - 500MOQ: 10 Pieces
-
Electromagnetic Flow Meter Chemical Industry, Orifice Plate Flowmeter, High Quality FlowmeterUS$ 1 - 100MOQ: 5 Sets
