1, product overview: LGK series orifice flowmeter is the standard orifice plate and multi-parameter differential pressure transmitter (or differential pressure transmitter, temperature transmitter and pressure transmitter) supporting high range differential pressure flow device, can measure gas, steam, liquid and flow, widely used in petroleum, chemical industry, metallurgy, electric power, heating, water supply and other fields of process control and measurement. Throttle device, also known as differential pressure flowmeter, is composed of a detection part (throttle part) and a secondary device (differential pressure transmitter and flow display instrument) is widely used in gas. Measurement of steam and liquid flow. It has simple structure, convenient maintenance and stable performance.

Ii. Working principle: LGK series orifice flowmeter is filled with pipeline fluid, when they flow through the flow orifice in the pipeline, the flow rate will form a local contraction at the orifice orifice throttle, so that the flow rate is accelerated, static pressure is reduced, so before and after the standard orifice there is a pressure drop or pressure difference, the greater the flow of the medium flow, the greater the pressure difference before and after the flow orifice, Therefore, the fluid flow rate can be measured by measuring the pressure difference. This measurement method is based on the principles of flow continuity equation (law of conservation of mass) and Bernoulli equation (law of conservation of energy). Based on the continuity principle of flow and Bernoulli equation, the relationship between flow pressure and flow rate can be derived under the condition of known relevant parameters. The basic formula is as follows:

c- outflow coefficient dimensionless d- working conditions throttle orifice or throat diameter of the throttling part D- working conditions upstream pipeline inner diameter qm- mass flow Kg/s qv- volume flow m3/s - diameter ratio d/D The density of the dimensionless fluid Kg/m3 expansion coefficient dimensionless

Three, application: LGK series orifice flowmeter is the standard orifice plate and multi-parameter differential pressure transmitter (or differential pressure transmitter, temperature transmitter and pressure transmitter) supporting the composition of high range specific differential pressure flow device, can measure the flow of gas, steam, liquid and natural gas, widely used in petroleum, chemical industry, metallurgy, electric power, heating, water supply and other fields of process control and measurement.

Four, the main characteristics:

1, throttle device structure is easy to copy, simple, firm, stable and reliable performance, long service life, low price. 2, hole plate calculation using international standards and processing. 3, wide application range, all single-phase flow can be measured, part of the miscible flow can also be applied. 4. Standard throttling device can be used without real current calibration. 5, a body hole plate installation is simpler, no pressure tube, can be directly connected to the differential pressure transmitter and pressure transmitter.

Five, technical parameters: caliber: DN25 ~ DN1000 (mm); Accuracy: ±1%FS; Range ratio: standard 1:13, extended 1:30; Working pressure: ≤42.0MPa; Medium temperature: -40C ~ 450C; Medium viscosity: ≤30CP (equivalent to heavy oil); β value: 0.2 ~ 0.8; Connection mode: flange or clamp type; Flange standard: DN≤600mm, PN2.0 ~ PN26,HG20616; PN32,HG20618; DN>600mm,PN2.0 ~ PN15,HG20623; It can also be manufactured according to user provided flange standards; Material: main body, orifice plate, pressure tube, three valve group: stainless steel; Straight pipe section and connecting flange: carbon steel or stainless steel; Installation mode: horizontal or vertical; Intelligent differential pressure transmitter: Output: 4 ~ 20mA.DC or digital signal; Power supply: 24V.DC; Explosion-proof grade: dⅡCT5.6, iaⅡCT4-6; Protection level: IP67; Table head: blind table and digital display table two. 1. Ring chamber pressure standard orifice plate: belongs to standard orifice plate. Because of the realization of ring chamber pressure, improve the measurement accuracy, shorten the installation required minimum length of linear pipe, can be widely used in various departments. 2, Angle connected single d.u drilling pressure standard hole plate: belongs to the standard hole plate. When the pipe diameter is more than 400 mm, this form is used. The method of taking pressure is single d.u bore pressure, round pressure balancing ring pressure or square pressure balancing ring pressure. Hole plate form can be with a handle hole or non - standard round hole plate. 3, flange pressure standard orifice plate: belongs to the standard orifice plate. Regardless of the diameter of the pipeline, the center of the upper and downstream pressure extraction holes are located at 1 hour (25.5mm) away from each end face on both sides of the hole plate. This form is widely used in the oil refining system. 4, diameter distance pressure standard orifice plate: belongs to the standard orifice plate. The pressure taking method is pipeline pressure taking. The center of the upstream pressure extraction hole is located in front of the hole plate at one times the pipe diameter. The center of the downstream pressure hole is located half of the inner diameter of the tube from the rear end face of the hole plate. 5. Orifice plate: It is a non-standard orifice plate. For measuring fluid in 10 mm to 50 mm diameters. 6. Double orifice plate: It is composed of two standard orifice plates installed in the straight pipe according to a certain distance from each other. According to the direction of the flow beam, the front hole is called the auxiliary hole plate, and the back hole plate is called the main hole plate. The section ratio m1 of the auxiliary orifice plate is larger than that m of the main orifice plate. The two orifice plates form a nozzle resembling a liquid wall. It is used for flow measurement of low Reynolds number fluids or high viscosity fluids. 7, round hole plate: is a non-standard hole plate, suitable for dirty, or have bubble analysis, or containing solid particles of fluid flow measurement, the measurement accuracy is low. 8. Conical entrance orifice plate: It belongs to non-standard orifice plate. The Angle between the circular cone and the center line is 45°. This conical inlet orificum can be used for very low Reynolds number situations, but the pipe size shall not be less than 25 mm.