LG standard orifice flowmeter has been widely applied in various fields of petroleum, chemical, metallurgy, electricity, heating, water, food, medicine and other process control and measurement commonly used standard flange throttle device and manufacturing standards: 1. The preferred Machinery Industry Ministry (JB81-59; JB82-59) Central Office to take pressure or drilling to take pressure, the span to take pressure and low-pressure connecting flange; 2 second choice Ministry of Chemical Industry (HG20592-1997, HG20615-1997) flange pressure ; or according to user need to use other criteria. 3. People's Republic of China home standard GB / 2624-2006. 4. People's Republic of China oil and gas industry provides three standard SY / T6143-. 5.JJG640-94 differential pressure flowmeter verification procedures. National Standard GB / T2624-93 kind of way to take pressure: A, corner tapping: include drilling to take pressure and the ring are two ways to take pressure chamber, donut take pressure will help improve accuracy and shorten the straight pipe, when β value is constant, the flow coefficient is a constant, less affected pipe roughness. B, flange pressure: the processing is simple, easy to install and clean up dirt, clogging, etc., but the accuracy is slightly lower than the corner tapping. C, the span Pressure: Pressure point is fixed for Reynolds big occasions, but the roughness greater impact. By measuring fluid classification: A, for the general measurement points, corner tapping standard orifice (including eight slot board is mainly used in power plants, high-voltage lens pad plates are mainly used chemical plants), flange pressure standard plate, take pressure away from the standard orifice diameter, corner tapping the standard nozzle (including eight slot nozzle mainly mainly used in power plants, high-pressure nozzle is mainly used in chemical plants lens mat), long-necked span to take pressure nozzles; B for horizontal pipelines measuring dirty media, corner tapping round orifice and eccentric orifice (both non-standard throttling device); C, for low Reynolds number flow, 1/4 round nozzle, dual orifice tapered inlet orifice (both non-standard throttling device); D, for applications requiring a low pressure loss occasion, the standard venturi tube, standard venturi nozzle; E, used for smaller diameter (pipe diameter 5 ㎜≤D≤49㎜), corner tapping orifice plate, small nozzle, orifice plate flange pressure ((both non-standard throttling device); in addition there are wear-resistant plates, end throttle ( plates, nozzles, etc.), double Venturi tube, limiting orifice, V-cone, pipe, rectangular Venturi tube, ring plate, wedge-shaped orifice, sonic nozzles and other non-standard throttling device. Standard throttling elements can be divided into: standard orifice plate, standard nozzle, nozzle diameter, 1/4 hole plate, double plate, eccentric orifice, round orifice, tapered inlet orifice advantages: 1, standard orifice is a wholly-use, and has been recognized ISO, without real-calibration, you can put into use, the flow sensor is unique; 2, the structure is easy to copy, simple, strong, stable and reliable performance, low price; 3 a wide range of applications, including all single-phase fluid (liquid, gas, steam), part of the mixed phase flow, diameter general production process, work status (temperature, pressure) are able to measure; 4 throttling device structure is easy to copy, simple, strong, stable and reliable performance, long life, low prices. wide range of applications 5, all single-phase flow measurement Jieke, some mixed phase flow can also be applied. 6 a body orifice plate installation easier, no impulse control, can be directly connected differential pressure transmitter and pressure transmitter.