Float flow meter in use because of some media and impurities cause flow change or flow in a numerical value does not change, this kind of reason is the fault of float fault, this paper introduces the metal tube float flowmeter measurement in the common fault and countermeasures.

Introduction to common float faults:

Ⅰ.The actual flow rate is inconsistent with the indicated value. Due to the changes in weight and volume of the corrosion float and the maximum diameter, the inner diameter of the conical tube changes.Replace with corrosion-resistant materials.If float size is the same as before replacement, it can be converted or re-calibrated according to the new weight and density.If the dimensions are different, they must be recalibrated.Float maximum diameter cylinder friction consumption surface rough, the impact of the measured value is quite large, a new float made of engineering plastic or lined float, may produce swelling, maximum diameter and volume change, for the table suitable material float.

Float, conical tube attached water dirt dirt and other foreign body layer.Cleaning to prevent damage to the inner surface of the conical tube and the maximum diameter of the float cylinder, maintain the original smoothness.

When the liquid property changes, the liquid density, viscosity and other properties are not consistent with the design. The flow rate can be corrected or evaluated according to the property parameters after the change.

The change of temperature and pressure of gas, steam and compressible fluid leads to the change of temperature and pressure and other operating conditions, which have a sensitive influence on the measured value of flow.

The flow pulsates, the gas pressure changes sharply, and the indicating value fluctuates. Although the influence of occasional float agitation is not significant, the system oscillates periodically. Therefore, the pipeline system must be equipped with a buffer device or an instrument with a damping mechanism.

The plate type float flowmeter mixes air bubbles into the liquid, and the influence of the density of the mixed liquid droplets in the gas changes, and the necessary improvement or exclusion is made. When used in liquids, the internal dead angle of the instrument retains gas, which affects the buoyancy of the float components. The small flow meter and the operation at low flow have significant effects on gas exclusion.

Ⅱ.When the flow rate changes and the float or pointer moves late, there are particles and other foreign matters between the float and the guide shaft or the guide shaft is stuck due to bending and other reasons, disassembly inspection, cleaning, removal of foreign matters or fixation layer, alignment of the guide shaft.The bending of the guide shaft is mostly caused by the quick opening and closing of the solenoid valve and the change of the operation mode caused by the impact of the sharp rise and fall of the float.

Iron powder or particles are attached around the magnet of the magnetic coupling float assembly. Remove and remove.At the beginning of operation, bypass view (that is, the fluid does not flow through the flow meter) is used to fully flush the pipe.To prevent long-term use, the pipe may produce rust, can be installed in front of the table magnetic filter.

The motion connecting rod that indicates part of the connecting rod or the pointer is stuck and is coupled with the magnet by hand.Check if there is any foreign matter between the rotating shaft and the bearing that impedes the movement, remove or replace the parts.Replace with new parts of dielectric resistant materials.Higher temperature medium as far as possible without plastic, the use of corrosion resistant metal parts.

Magnetic coupling of the magnet magnetic drop off the meter, with the hand down to move the float, confirm that the pointer part of the pointer to smoothly follow the movement.Do not follow or follow unstable replacement parts or magnetization.In order to prevent magnetic weakening, prohibit the two coupling to each other.

Common faults of float flowmeter

To sum up, the paper introduces the common fault causes and solutions, and it can be seen that many faults of the float itself can be avoided in use.In some corrosive media the correct selection is the first important point.Any flowmeter in the use of the correct selection and later use of maintenance is essential, can effectively ensure the purpose of field use and due to the accuracy of the guarantee.