The mediums that need to be measured in the site are different. Now, a brief introduction is made on the selection of flow meters for different media.
The selection of large water flow meter: suitable for electromagnetic flowmeter, ultrasonic flowmeter. Other applications such as vortex flowmeters, orifice flowmeters, etc. have faded out of this application, and these two types of flow meters are the most important in the industry. In particular, it should be mentioned that the application of Kaifeng Shengda's plug-in flowmeter and electromagnetic flowmeter are better.
Sewage, pulp and other turbid liquid meter selection: electromagnetic flowmeter can be used. However, when choosing an electromagnetic flowmeter, consider that the liquid does not contain more air or bubbles.
The meter with more bubbles of liquid selection: Doppler ultrasonic flowmeter can be selected, using this type of flowmeter to measure the fluid with bubbles, the effect is very good.
Flow meter selection with low conductivity such as pure water and demineralized water: Turbine flow meter is very suitable for measuring such fluids.
Flow meter selection for strong corrosive media such as acid and lye: 1. Electromagnetic flowmeter with acid and alkali lining. 2. clamp type ultrasonic flowmeter.
Selection of flowmeters for mediums with large concentration and large solid particle content such as mortar and electric powder slurry: electromagnetic flowmeter.
Flow meter selection for oil media such as oil and diesel: turbine flow meter and ultrasonic flow meter.
Gas flow meter selection: vortex flowmeter.
Turbine flowmeter composition
Turbine flowmeters are speed flowmeters, also known as impeller flowmeters. The impeller type flowmeter utilizes the relationship between the rotational angular velocity of the impeller placed in the fluid and the fluid flow velocity. By measuring the rotational speed of the impeller to reflect the volumetric flow rate of the fluid passing through the pipeline, it is a relatively mature high-accuracy instrument in the flowmeter. One. Turbine flowmeters generally consist of the following five typical parts:
1. Body
The material of the body is generally steel or cast iron, and the ends are flanged. The small diameter gauge also has a threaded interface.
2. Measured component
The turbine has precision machined blades that together with a set of reduction gears and bearings form the measuring assembly. The two high-precision stainless steel permanent self-lubricating bearings that support the turbine ensure a long service life of the assembly. Turbine flowmeters can also be lubricated with an external lubricant pump, but be careful not to overdo it.
3. counter
The following important information is available on the counter panel:
(1) Maximum working temperature and pressure:
(2) Metering and minimum and maximum flow levels
(3) Product model and number
(4) Explosion-proof grades and signs
(5) The equivalent of the fluid corresponding to the low frequency or high frequency pulse and the wiring method.
4. Rectifier
The rectifier is used to keep the fluid flowing through the turbine flow meter in a regular state, thereby eliminating the disturbance and having an unaffected effect on the metering. High metering accuracy.
5. Magnetic coupling transmission device
The device separates the counter portion in the atmospheric environment from the gas being measured and transmits the rotation of the measuring assembly to the counter.
Executive Standard: JB/T 9248-1999
Nominal diameter: 15, 20, 25, 32, 40, 50, 65, 80, 100, 125, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2400, 2600, 2800, 3000
Maximum flow rate: 15m/s
Accuracy: DNl5~DN600, indication: ±0.3% (flow rate ≥1m/s); ±3mm/s (flow rate <1m/s)
DN700-DN3000, ±0.5% of the indicated value (flow rate ≥0.8m/S); ±4mm/s (flow rate <0.8m/S)
Fluid conductivity ≥5uS/cm
Nominal pressure:
DNl5～DN: 1504.0MPa, DNl5～DN600: 1.6MPa, DN200～DN1000: 1.0MPa, DN700～DN3000: 0.6MPa, Special order: 6.3, 10MPa
Ambient temperature
Sensor: -25 °C - ten 60 °C
Converter and integrated type: -10 ° C - ten 60 °C
Lining material: PTFE, neoprene, polyurethane, polytetrafluoroethylene (F46), screened PFA
Maximum fluid temperature
- Body type 70 °C
Separate type: Polychloroprene lining 80 ° C; 120 °C (specify when ordering)
Polyurethane lining 80 °C
PTFE lining
Polytetrafluoroethylene propylene (F46) 100 °C; 150 °C (specify when ordering)
Screening PFA
Signal electrode and grounding electrode material: stainless steel 0Crl8Nil2M02Ti, Hastelloy C, Hastelloy B, titanium, tantalum, platinum/rhodium alloy, stainless steel coated tungsten carbide
Electrode scraper mechanism: DN300-DN3000
Connecting flange material: carbon steel
Grounding flange material: stainless steel 1Crl8Ni9Ti
Import protection:
DN65—DNl50: Stainless steel 1Crl8Ni9Ti
Flange material
DN200～DNl600: Carbon steel ten stainless steel 1Crl8Ni9Ti
Shell protection
DNl5～DN3000 separate rubber or polyurethane lining sensor: IP65 or IP68
Other sensors, body flow meters and split converters: IP65
Spacing (separate type): The converter distance sensor generally does not exceed 100m