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『Orifice differential pressure flowmeter』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)
1. What kind of instrument does an orifice flowmeter belong to?
An orifice flowmeter belongs to a differential pressure flow instrument.
1. Instrument classification attributes: 1 The measurement principle is based on the pressure difference generated upstream and downstream when the fluid flows through the throttling element (orifice plate), and the flow rate is calculated by measuring the differential pressure value, which conforms to the Bernoulli equation and continuity equation principles. According to the national standard classification based on GB/T 2624-2006 "Measurement of full pipe fluid flow using differential pressure devices installed in circular cross-section pipelines for seepage control", the orifice plate flowmeter is clearly classified as a differential pressure ridge flow detection instrument.
2. Core Features 1 Structural composition • Throttling device: standard orifice plate (with circular hole thin plate) • Pressure sensing device: corner joint pressure sensing/flange pressure sensing • Differential pressure transmitter: measures pressure difference and outputs signal • Flow meter: converts flow rate based on differential pressure value 2 Technical parameters (data source: Metrology Technical Specifications released by the State Administration for Market Regulation in 2023) • Accuracy level: ± 1.0%~± 2.5% • Reynolds number range: 5 × 10 ³~1 × 10 ⁷ • Diameter range: DN50~DN1000 • Applicable media: gas, liquid, steam
III. Application restrictions • Large permanent pressure loss (about 50%~90% differential pressure value) • Strict requirements for straight pipe sections (above 10D and 5D) • Not suitable for viscous and solid particle media • Range ratio usually not excee
2. What are the calculation formulas for differential pressure flow meters?
Give an example to illustrate the calculation method: the differential pressure range is 0-25KPA, the output is 4-20mA, the secondary flow meter is 0-200m3/h, and the flow rate is 80100.. There are detailed calculation formulas and operating procedures:
1. Generally speaking, flow rate and differential pressure are proportional, that is, F * F=K * △ P
2. Then K=F × F/△ P=200 * 200/25=1600
3. When the flow rate is 80m3/h: △ P1=F1 * F1/K=80 * 80/1600=4KPa
4. The current output is (20mA-4mA) × 4/25+4=6.56mA
5. When the flow rate is 100m3/h: △ P2=F2 * F2/K=100 * 100/1600=6.25KPa
6. The current output is (20mA-4mA) × 6.25/25+4=8mA. Additional information: Differential pressure (pressure) transmitter is a typical self balancing detection instrument that uses the working principle of negative feedback to overcome the influence of adverse factors such as component materials and processing technology. Differential pressure transmitters are used to measure the liquid level, density, and pressure of liquids, wide grinding gases, and vapors, and then convert them into 4-20mA DC current signals for output. The JT-3051DP can also communicate with each other through the BRAIN handheld hood lifter, CENTUM CS/μ XL, or HART 275 handheld controller for setting and monitoring. Among them: Q: volumetric flow rate; α: Flow coefficient ε: beam expansion coefficient d: orifice size Δ p: pressure difference Ρ 1: fluid density