I. Product Overview:

LGV series V-cone flowmeter uses the throttle effect generated by the V-cone in the flow field to measure the flow rate by detecting the upstream and downstream pressure difference. Compared with the ordinary throttling, it changes the throttling layout from the center hole throttling to the annular throttling. Practice has proved that compared with other flow meters, the flowmeter has the advantages of high long-term accuracy, good stability, limited by installation conditions, wear resistance, wide measuring range, small pressure loss, suitable for dirty media and so on. And the V-cone itself as a flow field rectifier has become a new flowmeter with excellent performance.

And the V-cone itself as a flow field rectifier becomes an excellent new flowmeter with d.u characteristics. The V-cone flowmeter, which is composed of V-cone sensor, differential pressure transmitter and intelligent flow integrator, can accurately measure the flow of various media in the range of wide Reynolds number (8×103≤Re≤5×107). Now V-cone has achieved international standardization, but it is a hot spot in the field of international flow measurement. It is believed that in the near future, with the further study and the improvement of theoretical and experimental data, it will become a standard throttling device like standard orifice plate, standard nozzle and classic Venturi flowmeter.

Ii. Working principle:

LGV series V-cone flowmeters include a pointed cone mounted coaxial in a measuring tube and a corresponding pressure port. The measuring tube is precision machined to generate a differential pressure at both ends of the pointed cone. The high pressure (positive pressure) of the differential pressure is the static pressure measured at the wall port before the upstream fluid contractions. The low pressure (negative pressure) is taken from the cone towards the downstream end cone central axis hole pressure.

The cone is oriented towards the incoming flow. Between the cone and its tail surface is a sharp and acute Angle. The edge of this meeting surface allows the fluid to have a smooth transition zone before entering the lower pressure area.

Because the fluid is not forced to shrink near the central axis of the pipeline, and is not a barrier to change the flow direction of the fluid, but the use of this novel V-cone throttling device to realize the gradual contraction of the fluid towards the side wall of the pipe, so that the V-cone flowmeter has a series of advantages. The low pressure side produces a small vortex with high frequency and low amplitude, so the differential pressure measured by the differential pressure transmitter is a low noise signal, which can make the differential pressure transmitter measure a very high resolution, so that the V cone can obtain a very wide range ratio and good repeatability.

The square root of the differential pressure value generated by the flow sensor is proportional to the flow rate:

Qv= (c.ε)/(1-β4) 0.5. (π/4).d2.0.5

Where: Qv: fluid volume flow rate

C: outflow coefficient;

ε : fluid expansibility coefficient;

β : throttling ratio;

d: diameter of throttle parts;

Delta Rho, differential pressure;

ρ1: density of fluid operating condition.

Iii. Application, Conditions and Maintenance:

Medium: Gas, natural gas (including humidity below 5%), all kinds of hydrocarbons (including wet HC gas), all kinds of noble gases (hydrogen, helium, argon, oxygen, nitrogen, etc.), wet chloride gas, air (including water, air containing SiO2 particles and other suspended solids), flue gas, saturated steam (containing steam and water two-phase flow), superheated steam, water, etc.

Strip: from deep cold to supercritical state, high temperature up to 700℃, pressure up to 40Mpa.

Calculation: Each cone is calculated using special software based on fluid properties, pressure and temperature. Users can according to their own application conditions (components of the measured medium, temperature, pressure, pipe diameter, large flow, common flow, small flow, permitted pressure loss) choose beta value.

Maintenance: Conical flowmeter is maintenance-free and does not require regular maintenance and verification.

Four, the main characteristics:

1. Accuracy can reach 0.5%.

2. The typical value of range ratio is 15:1, and at least 10:1, which is far better than traditional flowmeters such as orifice plate and nozzle.

3, repeatability is better than ± 0.1%.

4. The required straight pipe section is very short during installation, with 0 to 3D in the upstream and 0 to 1D in the downstream; There is no need to install a flow regulator upstream of the V cone. Greatly saving the cost and installation space under fixed working conditions.

5, flow meter structure design is fluid sweep type structure, it is impossible to intercept any enlivened gas, liquid or solid phase dirt in the fluid, very suitable for the flow measurement of dirty fluid, such as coke oven gas, wet gas, etc.

6. The specially designed inner cone can reduce the amplitude of pulsation (oscillation) in the measured pressure (differential pressure) field, so as to reduce the noise in the differential pressure signal. Smaller flow rate can be measured, so that the range is wider than.

7, no moving parts, high reliability, not easy to produce stuck.

8. When fluid flows through the inner cone with special profile, boundary layer will be formed around it and the fluid will be diverted away from the edge of the tail of the cone, so as to reduce the possibility of it being worn and ensure the stability of its performance.

9. Small pressure loss, small energy loss, dirt resistance. Suitable for low static pressure fluid flow measurement applications, such as flue gas.

10, easy to install, is the ideal flow meter for technical transformation.

11, maintenance-free or maintenance workload is small, with flow adjustment and mixing of fluids.

V. Technical parameters:

1, nominal passage: 50mm≤DN≤1800 mm;

2, nominal pressure: PN≤40Mpa;

3. Reynolds number range: 8×103≤Red≤107;

4, accuracy level: 0.5, 1.0;

5, repeatability: ≤ 0.1%;

6. Front straight pipe section: 1 ~ 3D, back straight pipe section: 3 ~ 5D;

7. Small pressure loss: only 1/2 ~ 1/3 of the orifice plate;

8. Cone rear edge produces small vortex, negative pressure side output is stable, small fluctuation and good stability;

9, range width: flow range can reach: 1:15.

Flange type:

1. Connection mode: flange (flat welding and butt welding);

2, caliber: DN15 ~ DN2000;

3, pressure: socket welding, flange, thread;

4, pressure: 0 ~ 40MPa;

5, temperature: -40 ~ 850℃;

6, Material: 304 stainless steel, 316L stainless steel, 20# carbon steel (see the selection table);

7, Application: liquid, gas, steam;

8, applicable media: widely used in municipal, electric power, chemical, petrochemical, metallurgy, food processing and other industries flow measurement, almost suitable for all gas, liquid media.

Direct welding type:

1. Connection mode: welding directly to the process pipeline;

2, caliber: DN15 ~ DN2000;

3, pressure: socket welding, flange, thread;

4, pressure: 0 ~ 40MPa;

5, temperature: -40 ~ 850℃;

6, material: 304 stainless steel, 316L stainless steel, 20# carbon steel;

7, Application: oil pipeline, gas pipeline, steam pipe network, high pressure process pipeline.