The installation and use of the flowmeter must pay attention to these matters!
The flowmeter is an indispensable instrument for measuring the flow of liquids and gases. Everyone must have seen many different types of flowmeters. The correct installation method is very important to the flowmeter. Today, the editor brings you the installation requirements of several common flowmeters. I hope it will be helpful to you.
Correct installation design
The measurement principle of the electromagnetic flowmeter does not depend on the characteristics of the flow rate. If there is a certain amount of turbulence and eddies in the pipeline in the non-measurement area, it has nothing to do with the measurement. If there is a steady-state eddy current in the measurement area, it will affect the stability and accuracy of the measurement. At this time, the length of the front and rear straight pipes can be increased, a flow stabilizer or the cross section of the measurement point can be reduced to stabilize the flow velocity distribution.
The flowmeter can be installed horizontally and vertically, but it should be ensured to avoid the influence of deposits and bubbles on the measuring electrode, and the electrode axis should be kept horizontal. When installed vertically, the fluid should flow from bottom to top.
Installation between elbows, valves and pumps
For vortex flowmeters, when measuring gas flow, if the measured gas contains a small amount of liquid, the flowmeter should be installed at a higher position in the pipeline. When measuring liquid, if the measured liquid contains a small amount of gas, the flowmeter should be installed at the lower part of the pipeline.
The installation of ultrasonic flowmeter mainly follows the following points:
1. Choose a pipe section filled with fluid that is uniform and dense and easy to ultrasonic transmission, such as a vertical pipe section or a horizontal pipe section.
2. The installation distance should be a straight pipe section with no valves, elbows, variable diameters, etc. within the upstream greater than 10 times the straight pipe diameter, and the downstream greater than 5 times the straight pipe diameter. The installation point should be sufficiently far away from valves, pumps, high-voltage electricity and Interference sources such as inverters.
3. Avoid installing on the highest point of the piping system or on vertical pipes with free outlets.
4. For open or half-full pipes, the flowmeter should be installed at the U-shaped pipe section.
The installation requirements are as follows:
1. The installation position of the flowmeter should be as far as possible to choose a straight pipe section with no valves, elbows, variable diameters, etc. within the upstream greater than 10 times the straight pipe diameter and the downstream greater than 5 times the straight pipe diameter. This installation condition will help ensure Have a more symmetrical velocity distribution profile;
2. In order to eliminate the adverse effects of condensate in the biogas pipeline, it is recommended that users install a sewage valve in front of the straight pipe section, and appropriately raise the installation position of the flowmeter, so that the condensate can be effectively discharged at the front end of the sewage outlet;
3. Parallel a bypass pipe section next to the biogas flowmeter pipeline to facilitate the maintenance of the flowmeter. The pipe at the entrance of the biogas flowmeter must be equipped with a valve to close the gas path. After installing the biogas flowmeter, check the tightness of the connection;
4. It is strictly forbidden to use open flame to detect leaks. The gas pressure entering the biogas flowmeter shall not exceed its specified maximum pressure value;
5. The inner diameter of the meter body should be consistent with the inner diameter of the straight pipe section, which is especially important for the straight pipe section upstream of the flowmeter;
6. The axis misalignment between the meter body of the flow meter and the connected straight pipe section is minimized, and the gas chamber should be installed horizontally;
7. If the gasket protrudes into the pipeline, it may cause interference to the flow field distribution. Measures should be taken to ensure that the gasket is on the flange sealing surface and remains concentric with the flange, and no gasket is allowed to penetrate the pipeline;
8. When installing, check whether the inner cavity of the measuring pipe section of the flowmeter is clean. If there is grease and dust, it must be cleaned up in time.
Through the introduction of the above-mentioned flowmeter, the flowmeter installation method under common working conditions has been relatively clear. For flowmeter installation under complex working conditions, specific analysis of specific conditions is required. Accumulating rich experience is the most important link to solve the problem. .