As an important instrument widely used in industrial flow measurement, the installation technology requirements of vortex flow meters are crucial to ensuring their accuracy and stability. These requirements include the selection of the installation environment, the correct location of the flow meter, the pipeline layout, and special technical details that need special attention during installation. The aim is to help engineers avoid common problems during installation and ensure that the vortex flow meter performs at its best.
1. Pipeline Conditions and Installation Location: Vortex flow meters must be installed on horizontal or vertical pipes to avoid measurement errors caused by tilted installation. For horizontal installation, the pipe should be filled with fluid and free of air bubbles; for vertical installation, the fluid flow should be from bottom to top to prevent sediment buildup. The installation location should be far away from pumps, valves, elbows, and other equipment prone to vibration. Typically, the upstream straight pipe section length should be 15-20 times the pipe diameter, and the downstream length 5-10 times, to ensure fluid stability. For example, if the pipe diameter is 100mm, the upstream straight pipe section should be 1.5-2 meters, and the downstream section 0.5-1 meter.
2. Installation Direction and Fluid Flow Direction: The flow meter body is marked with a flow direction arrow, which must be aligned with the fluid direction during installation. Incorrect direction can lead to abnormal signal output or even damage to the sensor. For gas measurement, ensure there is no liquid residue in the pipe; for liquid measurement, avoid gas contamination, as this may cause cavitation.
3. Straight Pipe Section Length and Flow Field Uniformity: The straight pipe section length is a key factor affecting measurement accuracy. If valves, elbows, or other obstructions exist upstream, eddy currents must be eliminated by extending the straight pipe section or installing a flow regulator. For example, installing a flow meter after a 90° elbow requires extending the upstream straight pipe section to at least 30 times its diameter. For high-precision applications, a vortex flow meter with a built-in rectifier can be used to reduce reliance on the straight pipe section.
4. Environmental Factors and Protective Measures: The installation environment must avoid strong electromagnetic interference, high or low temperatures. If the ambient temperature exceeds the instrument's allowable range (typically -20°C to +60°C), insulation or heating measures are required. Furthermore, rainwater and dust must be prevented from entering the instrument; it is recommended to install a protective cover or select a product with a higher protection rating.
5. Electrical Connections and Grounding: The signal line of the vortex flow meter must use shielded cable and be laid in a separate conduit, avoiding parallel operation with power cables. The grounding resistance must be less than 4Ω to prevent signal interference. If the instrument needs to transmit signals remotely, an intrinsically safe or explosion-proof product meeting explosion-proof requirements must be selected.
Vortex Flowmeter Installation Tips
1. Vortex flowmeters can only measure in one direction. During installation, ensure the direction of the medium flow is consistent with the direction indicated by the arrow on the flowmeter.
2. Vortex flowmeters are installed vertically, with the medium flowing from bottom to top. Install the flowmeter on a vertical pipe with the flow direction from bottom to top.
3. For horizontal installation, the flowmeter must be installed in the high-pressure zone of the system, ensuring the corresponding outlet pressure. Do not install it at the highest point of the pipeline, as gas often accumulates there, and the pipe may not be full; the outlet should not be directly vented.
4. When measuring high-temperature fluids, vertical installation is preferred. If horizontal installation is unavoidable, position the transmitter section of the flowmeter vertically downwards or horizontally to the side to avoid excessive temperature. Ensure good airflow or ventilation at the installation location.
5. Straight pipe requirements: At least 15 times the pipe diameter upstream of the flowmeter and 5 times the pipe diameter downstream of the flowmeter. If there are bends, indentations, or expansion joints before the flow meter, ensure a pipe diameter of 30-40 times before the flow meter and 6 times after the flow meter. The flow meter should be installed upstream of the regulating valve, pressure, or temperature sensor.
6. During installation, ensure the pipe diameter is slightly larger than or equal to the instrument's inner diameter.
7. When using a sealing ring, ensure the sealing ring's inner diameter is slightly larger than or equal to the instrument's inner diameter, and the center of the sealing ring is located in the pipe.
8. When using a vortex flow meter for flow regulation, the vortex flow meter sensor should be installed upstream of the regulating valve. Otherwise, at low flow rates, the jet generated by the regulating valve will affect the vortex flow meter's measurement, resulting in a phenomenon where opening the valve slightly increases the flow rate.
The installation of a vortex flow meter is not merely a simple operational process; it involves knowledge of multiple aspects, including pipeline design, fluid mechanics, and equipment selection. Only by adhering to strict technical requirements can the accuracy and long-term stability of the vortex flow meter be ensured, thereby providing reliable data support for industrial production.