Pressure and temperature selection
The actual working pressure of the fluid in the pipeline should be less than the rated working pressure of the flowmeter. Pay attention to whether there is negative pressure in the pipeline, such as the evaporation process, and the negative pressure is up to -60KPa. Such working conditions should be communicated with the manufacturer's technicians when ordering. Strict requirements are imposed on the lining material. The actual temperature should meet the temperature requirements specified by the flowmeter.
Power supply selection
The choice of the electromagnetic flowmeter power supply should be selected according to the flowmeter itself and the environment of the site. If the site allows, the power supply is convenient, safe and easy to maintain. As a chemical company, more than 90% of the raw materials and process links are in the liquid phase. During operation, the internal humidity of the workshop is large, and no flammable gas is generated during the whole operation. It is safer to use DC24V for power supply. Outdoor dry environment, choose AC220V power supply, convenient lead wire, good maintenance and low cost.
Some explosion-proof occasions, such as flowmeters used in gas boilers, are ideal for battery-powered electromagnetic flowmeters.
Vortex flowmeter installation requirements for straight pipe sections:
It is very important that the vortex flowmeter installation meets the requirements for straight pipe sections. Its detailed requirements are as follows:
The flowmeter has certain requirements on the upstream and downstream straight pipe sections at the installation point, otherwise it will affect the measurement accuracy.
If there is a tapered pipe upstream of the installation point of the flowmeter, there should be a straight pipe section of not less than 15D (D is the pipe diameter) upstream of the flowmeter, and a straight pipe section of not less than 5D in the downstream.
If there is a diverging pipe upstream of the installation point of the flowmeter, the upstream of the flowmeter shall have a straight pipe section of not less than 18D (D is the pipe diameter), and the downstream shall have a straight pipe section of not less than 5D.
If there is a 90° elbow or down joint upstream of the installation point of the flowmeter, there should be a straight pipe section of not less than 20D upstream of the flowmeter, and a straight pipe section of not less than 5D downstream.
If there is a 90° elbow on the same plane upstream of the installation point of the flowmeter, there should be a straight pipe section of not less than 25D upstream of the flowmeter, and a straight pipe section of not less than 5D downstream.
The flow regulating valve or pressure regulating valve should be installed as far as possible downstream of the flowmeter 5D. If it must be installed upstream of the flowmeter, the upstream of the flowmeter should have a straight pipe section of not less than 25D, and the downstream should have a straight pipe section of not less than 5D. .
If there is a piston type or plunger type pump in the upstream of the flow meter, a piston type or a Roots type fan and a compressor, the upstream of the flow meter should have a straight pipe section of not less than 25D, and the downstream should have a straight pipe section of not less than 5D.
Special attention: If the valve is installed near the upstream of the installation point of the vortex flowmeter, the valve is continuously opened and closed, which has a great influence on the service life of the flowmeter, and it is very easy to cause permanent damage to the flowmeter. The flowmeter should be avoided to be installed on the very long pipelines in overhead. After a long time, the leakage of the flowmeter can easily cause the leakage of the flowmeter to the flange. If it has to be installed, it must be in the upstream and downstream of the flowmeter. Pipe fastening devices are provided separately.
Vortex flowmeter installation method
1. The vortex flowmeter can only be measured in one direction. The installation should pay attention to ensure that the direction of the medium flow is consistent with the direction indicated by the flowmeter arrow.
2. The best installation method of the vortex flowmeter is vertical installation, and the medium passes through the flowmeter from bottom to top. Install the flowmeter on a vertical pipe with the flow direction from bottom to top.
3. When installing horizontally, the flowmeter must be installed in the high pressure zone of the whole system and ensure the corresponding outlet pressure; do not install at the highest point of the pipeline, because the highest point is often gas accumulation, the pipeline is not full, and the outlet cannot be directly emptied.
4. When measuring high temperature fluid, try to use vertical installation; if you have to install horizontally, please install the transmitter part of the flowmeter vertically downwards or horizontally to avoid excessive temperature; pay attention to air flow at installation location Or well ventilated.
5. Straight pipe section requirements: at least 15 times the pipe diameter before the flow meter and 5 times the pipe diameter after the flow meter. If there are elbows, indents, expansions and other sources of interference in front of the flowmeter, the diameter of the flowmeter should be 30–40 times, and the diameter of the flowmeter should be 6 times. The flow meter should be installed upstream of the regulator valve, pressure or temperature sensor.
6. When installing, pay attention to the pipe diameter should be slightly larger than or equal to the inner diameter of the instrument.
7. When using the sealing ring, the inner diameter of the sealing ring should be slightly larger than or equal to the inner diameter of the instrument, and the center of the sealing ring is at the center of the pipe.