Orifice flowmeter (also known as differential pressure flowmeter)

I. Overview orifice flowmeter orifice flowmeter is also known as differential pressure flowmeter is determined by a detecting member (orifice) and the secondary device (differential pressure transmitter and flow indicator which is widely applied in gas , vapor and liquid flow measurement. has a simple structure, easy maintenance, stable performance, and reliability. Orifice throttling device is a standard orifice may need calibration directly in accordance with national standards, a National Standard GB2624-81 < flow measurement throttling device design, installation and use "; 2. International Standards ISO5167 ; 3. Ministry of Chemical Industry Standard GJ516-87-HK06 Second, the orifice flowmeter works full throttle fluid flow through the pipeline within the pipeline, causing local contraction in the vicinity of the orifice plate, flow rate increases, in the upstream and downstream sides of which generates static pressure difference in the conditions of the relevant parameters are known, according to the flow continuity principle and Bernoulli's equation can be derived relationship between the differential pressure and flow rate and the flow rate obtained basic formula is as follows:. c- dimensionless orifice discharge coefficient of orifice or throat diameter D- d- under working conditions Under operating conditions the mass flow upstream pipe diameter qm- Kg / s qv- volume flow m3 / s -? diameter ratio d / D non dimensionless fluid density Kg / m3 expandable three dimensionless coefficient, throttling orifice flowmeter structure device component 1, cutting pieces: standard plate, the standard nozzle, nozzle diameter, 1/4 hole plate, double plate, eccentric orifice, round orifice, conical entrance orifice plate 2, to take pressure. Device: donut, take pressure flange, clamp ring, connecting pipe, etc. 3, connecting flange (the national standard, a variety of standards and other design department flanges), fasteners 4, the measuring tube.