The AFTLGWY series of liquid turbine flow meter consist of sensors and transmitters.The intelligent liquid turbine flow meter refers to the meter head section with on-site display of cumulative and instantaneous flow, 24V power supply, output current or pulse signal. The sensor is the same as the normal one, and the installation requirements are the same.
1）The turbine flow meter installation site
- The installation site should meet the ambient temperature in the range of -25 ~ 55 ° C, humidity <80% RH
- Good ventilation, avoid sun, rain
- Avoid places where the piping has vibration or stress.
- Avoid places that are susceptible to intense heat radiation and radioactivity
- Must avoid the interference of the external strong electromagnetic field on the detection signal. If it cannot be avoided, a shield or other measure should be added to the amplifier of the flow meter (sensor) to eliminate the interference.
- In places with explosion-proof requirements, explosion-proof amplifiers should be used.
- The installation location should be considered for easy installation, operation, maintenance
2) The turbine flow meter installation posture and position
In order to ensure a high measurement accuracy, the flow meter (sensor) should be horizontally mounted on the horizontal pipe, and the direction of the arrow indicating the flow direction on the flow sensor is consistent with the flow direction of the liquid. If it must be installed vertically, the flow of liquid should be from bottom to top to ensure that the body of the flow sensor is filled with liquid.
3)Piping requirements
- In order to eliminate the influence of the uneven distribution of the cross-section velocity in the pipeline on the measurement accuracy, the upstream and downstream of the flow sensor should have a certain straight pipe section, or a rectifier should be installed instead of a part of the straight pipe section. Generally, the upstream straight pipe section is not less than 15D, and the downstream straight pipe section is not less than 5D (D is the flow sensor nominal diameter).
- In order to eliminate the backflow, uneven flow velocity distribution and swirling effect, the rectifier can be installed upstream. At this time, the length of the straight pipe in the upstream part of the flow sensor can be L=10D. If it is 15-20D, the measurement accuracy can be reached. Calibration accuracy.
- When the liquid to be tested contains solid impurities, the filter should be installed upstream of the flow sensor. The mesh size of the filter is 20 to 60 mesh (3 to 9 mesh/cm2), and the diameter of the general flow sensor is small. some. The installation position of the filter should be considered to facilitate the disassembly and assembly of the filter.
- When a gas is mixed in the liquid or a liquid that is easily vaporized is measured, an air separator (degasser) should be installed.
- If the liquid to be tested is easily vaporized, in order to prevent the generation of air pockets, the pressure at the outlet end of the flow sensor should be higher than the calculated value Pmin:
Pmin = 2△P 1.25Pv
Where: Pmin – minimum pressure; △ P – pressure loss of the flow meter at the maximum flow rate;
Pv—the saturated vapor pressure of the liquid to be measured at the highest operating temperature
- When the flow rate through the flow sensor is too large, the bearing life will be too short. Usually, the flow rate will be adjusted to the appropriate size through the valve, and the valve should be installed downstream of the flow meter.
- In order to prevent fluid transfer during maintenance, a shut-off valve is usually installed upstream and downstream of the flow sensor, and a bypass pipe is provided at the same time, and the bypass pipe should be ensured that the bypass pipe does not leak when the bypass valve is closed.
- If there is a possibility of reverse flow, a check valve should be added to prevent reverse flow of fluid.
- The flow sensor should be concentric with the pipeline, and the seal ring must not protrude into the pipeline.
- In order to avoid gas accumulation in the flow meter, the flow meter should not be installed at the highest point of the horizontal pipeline.
- If the flow meter is installed at the low point of the pipeline, a drain valve should be installed on the pipeline to periodically discharge the sediment.
- The front and rear pipes of the flow sensor should be supported firmly so that there is no obvious vibration.
- When cleaning the newly laid pipeline, a short pipe should be connected to the part where the flow sensor is installed. After the cleaning is completed, the flow sensor should be installed.
- When measuring the temperature of the fluid, it should be measured at the length of the pipe nominal diameter of 5 times downstream of the flow sensor.
- When measuring the pressure of the fluid, it should be measured at the length of the pipe nominal 10 times upstream of the flow sensor.
