The form and selection of special throtting device 1、Air foil type volume measuring device The Air foil type volume measuring device is a flow measuring instrement which is now widely used for the application of once and quadratic blast measurement in domestic electric power industry.Comparing with other blast devices,it has the merits as follows: a.It has the special type of wing line,which can produce larger differential pressure and measure steadily. b.It adopts the structure of the double wings or multi-wings.The length of the device is short and the desired up-and-down course straight pipe section is also shorter. c.Its pressure loss is smaller and the pressure loss is not exceeded 14% of the differential pressure value. d.Its flows are even and steady,which has a fixed rectification action to the liquid. e.It is easy to be installed and serviced. f.It has higher accuracy and its erroe is not exceeded 2% within 30～100% range of maximum flow. Model：LGJT-A(flange connection) 　　　　　 LGJT-B(welding) Pressure method：special pressure Applied pressure：≤1.6MPa Applied pipe diameter：≥300mm Component standard：the industrial standard Stricture Form：(Shown as the right picture) 2、Two-tier Venturi tube and Plugging Type Flowmeter with Low Pressure Loss It is suitable for the flow measurement of various quadrate pipes and round pipes.It has the merits of small perssure loss,low prices and shorter length of the desired straight pipe section.And it is most suitable for the measurement of large pipe dimeters and large flow. Model：LGST LGFT Pressure method：special pressure Applied pressure：≤6.4MPa Applied pipe diameter：360～3000mm Component standard：the industrial standard Stricture Form：(Shown as the left picture) 3、Uniform Velocity Pipe(Annubar flowmeter) It is suitable for the flow measurement of various quadrate pipes and round pipes.It has the merits of small permanent pressure loss,low prices and shorter length of the desired straight pipe section.And it is most suitable for the measurement of large pipe diameters and large flow and also widely used for the blast measurement. Model：LGZT Pressure method：special pressure Applied pressure：0.01～6.4MPa Applied pipe diameter：25～3000mm Component standard：the industrial standard Stricture Form：(Shown as the left picture) 4、1/4Round Orifice Plate Fastigiate Entry Orifice Plate and two-tier orifice plate To the place of small Reynolds numbers and high media viscosity,it si difficult to reach the demand that using orifice plate and nozzle,etc.to make the measurement.And the 1/4 orifice plate was specially designed for that. Model：LGEH LGEF LGRH LGYH Pressure method：the ring chamber pressure,the drilling pressure,the flange pressure(D≥40) Applied pressure：≤1.6MPa Applied pipe diameter：25～400mm Component standard：the industrial standard Stricture Form：(Shown as the left picture) 5、Segmental Orifice Plate with Excenric Orifice Plate It is suitable for making the flow measurement of dirty media.It can make the media of the depositing impurity and the suspended substance easy passing the orifice plate without producing the stack layers to influence the measurement. Model：LGQZ LGQF LGQJ Pressure method：the drilling pressure,the flange pressure,D-D/2 pressure Applied pressure：≤16.0MPa Applied pipe diameter：50～2000mm Component standard：the industrial standard Stricture Form：(Shown as the left picture) 6、Integer Small Orifice Plate,inner Small Orifice Plate It is suitable for making the flow measurement in the place of the pipe with the inner diameter less than 50mm. Model：LGMZ LGNF Pressure method：the corner joint pressure,the flange pressure Applied pressure：≤16.0MPa Applied pipe diameter：15～50mm Component standard：the industrial standard Stricture Form：(Shown as the left picture) 7、High-pressure Lens Washer Orifice Plate It is suitable for making the flow measurement in the place of the pressure over 20Mpa.Generally,it is widely used in the high-pressure sites of the chemical and oil refining industrial departments. Model：LGGH Pressure method：the corner joint pressure Applied pressure：≥20MPa Applied pipe diameter：15～150mm Component standard：the industrial standard Stricture Form：(Shown as the left picture)