Installation tips of the turbine flowmeter
Author:vacorda Source:vacorda.com Date: 2016-12-27 17:20:39
Intelligent turbine flowmeter is the use of turbine flow sensor of ultra low power single chip microprocessor technology advanced and show that the new intelligent instrument product integration, using double crystalfield display, and has the advantages of compact mechanism, clear reading,high reliability, free from outside interference power, anti lightning and low cost.
The intelligent turbine flowmeter refers to the header part with the scene shows the cumulative and instantaneous flow, 24V power supply, output current or pulse signal, the sensor is the same as the general one, so as to the installation requirements.
(Intelligent turbine flowmeter)
First, The installation sites of turbine flowmeter
- Installation site should meet the ambient temperature in the range of -25 ~ 55 ℃, humidity <80% RH
- Well ventilated, avoid sun and rain;
- To avoid the vibration or stress in the piping;
- To avoid susceptible to strong heat radiation, radioactive effects;
- Must avoid the detection signal interference caused by the external strong electromagnetic field on . If it can not be avoided, should add a shielding in the flowmeter (sensor) of the amplifier to eliminate interference;
- it should install an explosion-proof amplifier when it has the explosion-proof requirements;
- For the installation location,it should consider easy installation, operation and maintenance.
Second, The turbine flowmeter installation position
In order to ensure a high measurement accuracy, the flowmeter (sensor) should be installed horizontally on the horizontal pipe, and the direction of the arrow on the flow sensor indicates the flow direction of the liquid. If it must be mounted vertically, the flow of liquid should be from bottom to top to ensure that the body of the flow sensor is filled with liquid.
Third, Piping requirements
1. In order to eliminate the influence of the uneven flow velocity distribution in the pipe cross-section on the measurement accuracy, the flow sensor should have a certain straight pipe upstream and downstream, or install rectifier instead of straight pipe. In general, the upstream straight pipe is not less than 15D, the downstream straight pipe is not less than 5D (D for the flow sensor nominal diameter);
2. In order to eliminate the influence of the backflow, uneven velocity distribution and swirl flow it can install a rectifier in the upstream, the flow sensor upstream part of the straight tube length is 10D, if the 15 ~ 20D, the measurement accuracy can achieve the calibration accuracy;
3. When the measured liquid contains solid impurities, a filter should be installed in the upstream of flow sensor, and the location of the filter should be considered to easily disassemble of the filter;
4.Install the air separator (air scrubber) when the liquid is mixed with a gas or when measuring liquids that are easy to vaporize. .
5.If the measured liquid is easy to vaporize, in order to prevent the generation of cavitation, the flow sensor output pressure should be higher than the following formula: Pmin
Pmin = 2△P 1.25Pv
In the formula:
△P—Pressure loss under the max flow;
Pv—The saturated vapor pressure of the measured liquid at the highest service temperature.
6. Flow through the flow sensor is too large, it will decrease the bearing life, usually through the valve to adjust the flow to the appropriate size, and the valve should be installed downstream of the flow meter;
7. In order not to interrupt the flow of fluid during servicing, a shut-off valve is normally installed both upstream and downstream of the flow sensor and a bypass line shall be provided and the by-pass shall not leak when the bypass valve is closed;
8. If possible reverse flow, should be added check valve to prevent the reverse flow of fluid;
9. Flow sensor should be concentric with the pipeline, the sealing ring shall not protrude into the pipeline;
10. To avoid gas accumulation in the flowmeter, the flowmeter should not be installed at the highest point of the horizontal line;
11. If the flowmeter is installed at the low point of the line, install a drain valve on the line, periodically draining the sediment;
12. Flow sensor should be supported firmly before and after the pipeline to avoid the significant vibration;
13. When cleaning the newly installed pipe, first install a short pipe in the area where the flow sensor is installed, and then install the flow sensor after cleaning;
14. When it need to measure the temperature of the fluid, it should be measured at the position of 5 times the length of the nominal diameter of the pipe downstream of the flow sensor;
15. When it need to measure the temperature of the fluid, it should be measured at the position of 10 times the length of the nominal diameter of the pipe downstream of the flow sensor.