STNZ V-cone flowmeter

1、 Overview of V-cone flow sensor: Although differential pressure flow meters represented by orifice plates, nozzles, Venturi tubes, and averaging tubes have undergone a long development process and made important contributions to flow measurement in a certain period of time, people always feel a bit regretful when using the above flow sensors because they have not solved a series of problems such as low accuracy, narrow measurement range, easy wear, high on-site installation conditions, and inability to measure mixed phase flow, dirty flow, etc. In view of this, numerous flow experts at home and abroad are committed to the research and development of new differential pressure flow sensors to compensate for the shortcomings of orifice plates and other throttling components. The V-shaped cone flow sensor has successfully solved the above problems. The new throttling element is a V-shaped structure suspended at the center of the pipeline, allowing the fluid to flow along the pipe wall after being compressed by a cone. This change in throttling method has revolutionized the differential pressure flowmeter, endowing the new throttling device with significantly better quality compared to previous throttling instruments.

2、 The working principle of the V-cone flow sensor: The SKVZ V-cone flow sensor is a V-cone suspended at the center of the measuring tube. When the fluid flows through the cone, its kinetic energy increases while its potential energy decreases. A low-pressure zone is formed downstream of the V-cone, resulting in a static pressure difference (i.e. differential pressure) between the front and back of the V-cone. According to Bernoulli's equation and the law of conservation of energy, Qm=C ÷ (1- β 4) 0.5 × (π ÷ 4) × ε× (D2-d2) × (2 × Δ P ÷ ρ) 0.5 Qv=Qm ÷ ρ, where Qm - mass flow rate (Kg/h). Qv - Volume flow rate (m3/h). ε - coefficient of gas expansion, dimensionless, ε=1 for incompressible fluids. Δ P - Differential pressure (Pa). ρ - density of fluid in working state (Kg/m3). C-outflow coefficient, obtained from actual calibration. β - Equivalent diameter ratio. β=(1-d2 ÷ D2) 0.5 D - Inner diameter of pipeline (mm). D - Maximum outer diameter of the cone (mm). For a V-shaped cone flow sensor, when the measured medium and cone are determined: Qm=K × (Δ P × ρ) 0.5, where K is the instrument coefficient. Δ P - Differential pressure. ρ - density of fluid in working state (Kg/m3).

3、 Main features: 1. There is no requirement for straight pipe sections. As the cone is located on the central axis of the pipeline, it has the function of reshaping the streamline. In the narrow areas upstream and downstream near the cone (front 0-3D, back 0-1D), the irregular fluid flow is directly rectified into ideal fluid, which can fully meet the requirements of Bernoulli's theorem and achieve high measurement accuracy and repeatability without the need for straight pipe sections for rectification. Successfully solved the problem of other forms of throttling components requiring a long straight pipe section for rectification. 2. High measurement accuracy and good repeatability. Due to the fact that the positive pressure tapping hole of the V-shaped cone flow sensor is located on the pipe wall upstream of the cone, and the pressure tapping position is selected in the constant velocity region of the ideal fluid, which conforms to Bernoulli's theorem, the positive pressure signal is stable; The negative pressure tapping hole is located at the center of the tail of the cone, which is the area with the lowest pressure downstream of the cone. Due to the symmetrical structure of the center of the cone, the flow field at the center of the tail of the cone presents a relatively static state. Although high-frequency and low amplitude small eddies appear at the tail of the cone after fluid throttling, they have little effect on the negative pressure signal, and the output differential pressure signal is very stable. The measurement accuracy is better than ± 0.5, the repeatability is ± 0.1, and the accuracy of trade measurement type is ± 0.3. 3. Wide range ratio, low pressure loss, and strong long-term stability. The normal range ratio of a V-shaped cone flow sensor is 15:1, and when selecting appropriate parameters, it can achieve 30:1. The streamlined conical throttling element reduces pressure loss to about 1/10 of the orifice plate. And due to the streamlined design of the cone, the fluid has minimal wear on it, resulting in strong long-term stability. 4. The adaptability of measuring media is strong, and it has good measurement performance for all known fluids including steam, gas, liquid, two-phase and multiphase fluids. At the same time, the cone is located at the center of the pipeline, and the fluid is accelerated between the cone and the pipe wall, giving it self-cleaning function and good measurement performance for dirty media and viscous fluids.

4、 V-cone flow sensor types, classification, connection forms, pressure measurement methods, pipe diameter (mm), applicable pressure (MPa), applicable temperature (℃), material, applicable medium, pipeline, butt welding connection type, pipeline, butt welding connection type, 1/2 "NPT thread pressure measurement, 40-1600, 0-42-196-850, various materials, crude oil, finished oil, natural gas, various gases, various steam pipelines, flange connection type A, pipeline flange connection type, 1/4" or 1/2 "NPT thread pressure measurement, valve connection pressure measurement, 15-2000, 0-42-196-850, various materials, various liquids, natural gas, various gases, various steam outer ring chambers, pipeline, butt welding or flange connection, 1/2" NPT thread pressure measurement or valve connection, 150-1600, 00-1600. 42-196~850 Various materials of crude oil, refined oil, natural gas, various gases, various steam pipeline flange connection type B Pipeline flange connection type 1.5 "~2" double flange pressure tapping 50~1600 0~42~196~850 Various materials viscous liquids, dirty gases, steam flanges clamp type flange clamp 1/2 "NPT, RC thread pressure tapping, outer ring chamber pressure tapping 10~150 0~42~196~850 Various materials small pipe diameter high flow medium pipe flanges can be selected according to user requirements. Standards: HG20595, JB/T82, HG20617, ANSI.

5、 Installation size 1. Flange clamp type: model SKVZ - integral structure type P (pressure type) ANSI/HG20615 CL 150-2500 JB/T HG20592 PN0.25-25.0 A (mm) B (mm) C (mm) A (mm) B (mm) C (mm) NPT (60 ○) RC (55 ○) 15 13.87 36 60 13.87 46 60 1/16 1/8 20 18.85 44 60 18.85 56 1/16 1/8 25 24.31 52 60 24.31 65 60 1/16 1/8 40 38.10 74 80 84 80 1/8 1/4 50 49.25 92 85 49.25 100 85 1/8 1/4 65 59.00 105 100 59.00 00 120 100 1/8 1/4 80 73.66 127 120 73.66 132 120 1/4 1/4 100 97.18 158 150 97.18 156 150 1/4 125 122.30 186 200 122.30 184 200 1/4 150 146.33 216 240 146.33 212 240 1/4 1/4 Note: 1. Suitable for measuring medium flow rate in small diameter high-speed pipelines 2. Flange standard: ANSI B16.5/HG 20617 JB/T80/HG 20595 3. Flange pressure rating (CL/MPa): 150-2500/2.0-42.0; PN0.25-25.0 4. Features: ① No welding is required during installation. ② The cone can be replaced. 2. Pipeline flange connection type low pressure: (PN ≤ 2.5MPa) size table