Industry new

Classification of the throttling device and description of the staff

We usually refer to the throttling devices listed in LS0 5167 (or CB/T 2624) as standard throttling devices, others are called non-standard throttling devices. It should be noted that non-standard throttling devices are not only those throttling devices. The structure is different from the standard throttling device. If the standard throttling device works under deviation from the standard conditions, it should also be called a non-standard throttling device. For example, the standard orifice plate works under the critical flow in the mixed phase flow or the standard venturi nozzle. Yes.
At present, there are some types of non-standard throttling devices:
1) Low Reynolds number with 1/4 round hole plate, tapered population orifice plate, double orifice plate, double inclined orifice plate, semi-circular orifice plate, etc.;
2) Round hole plate, eccentric plate, annular plate, wedge plate, elbow throttle, etc. for dirty media;
3) Low pressure loss with Roths tube, Dow tube, Dow orifice plate, double venturi nozzle, universal venturi tube, Vasy tube, etc.;
4) The whole (built-in) orifice plate for small pipe diameter;
5) end orifice device end orifice plate, end nozzle + Borda tube, etc.;
6) Wide-range throttling load elastic loading variable area variable head flowmeter (linear orifice plate);
7) capillary throttle flowmeter;
8) pulsating flow throttling device;
9) a critical flow throttling device sonic venturi nozzle;
10) Mixed phase flow throttling device.
The continuous expansion of throttling DPF field applications will inevitably require the development of non-standard throttling devices. For more than ten years, ISO has been continuously developing technical documents on non-standard throttling devices, and published them as technical reports before they can become official standards. . It is foreseeable that in the future it will be possible for some of the more mature non-standard throttling devices to be promoted to the standard type.
In the mid-to-late 1990s, the sales volume of various types of DPF in the world accounted for 50%-60u/o (about one million units per year) in the total amount of flow meters, and the amount accounted for about 30%. The number of sales in China accounts for about 35% to 42% of the total flow meter (excluding household gas meters and household water meters and glass tube float flowmeters) (60,000 and 70,000 units per year).

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