Precautions for using metal tube float flowmeter

Project Overview

When using a metal pipe float flowmeter, the damage caused by the water hammer effect refers to the smooth inner wall of the pipe and the free flow of water in the pipe. When an open valve is suddenly closed, the water flow will generate pressure on the valve and pipe wall, mainly the valve. Because the pipe wall is smooth, subsequent water flow will quickly reach the mouth under the action of inertia, causing damage. This is the "water hammer effect" in hydraulics, that is, positive water hammer. This factor should be considered in the construction of water conservancy pipelines. On the contrary, when a closed valve suddenly opens, water hammer will also occur. This is the so-called negative water hammer. It also has some destructive power, but not as much as the former.

Water hammer is when the power supply is suddenly cut off or the valve is closed too quickly, a shock wave is generated due to the inertia of the pressurized water flow, just like a hammer, so it is called water hammer. The force generated by the back and forth shock waves of water flow is sometimes so great that it can damage valves and pumps. When the electric water pump is started under the combined voltage, it can accelerate from standstill to the rated speed in less than 1 second, and the flow rate in the pipe increases from zero to the rated flow rate. Since fluids have momentum and compressibility to a certain extent, rapid changes in flow can cause overpressure or underpressure impacts and "cavitation" phenomena in pipelines. The impact of pressure forces the pipe wall to produce noise, like a hammer striking the pipe. This is the so-called "water hammer effect."

Water hammer is extremely destructive: if the pressure is too high, it can cause pipes to rupture. Otherwise, if the pressure is too low, it will cause the pipeline to collapse and damage the valve and fixed parts.

When the power is cut off and the machine stops, the potential energy of the pumping system will overcome the inertia of the motor, and the naming system will stop sharply, which will also cause pressure shock and water hammer effects.

In order to eliminate the serious consequences of water hammer effect, a series of buffer measures and equipment are needed in the pipeline.