Selection principles of rotary piston flowmeter

　　Rotating piston flowmeterIt is a volumetric flowmeter mainly used for measuring the volumetric flow rate of liquids. The biggest feature of the rotary piston flowmeter is its suitability for small flow measurement. It can display accumulated traffic locally and has a remote transmission output interface. When the flow rotary piston flowmeter is equipped with LPJ-12D (or LPJ-12D/FI type) photoelectric pulse standard converter, it can output pulse signals or 4-20mA DC standard current signals, achieving the purpose of signal remote transmission.

The rotary piston flowmeter has the characteristics of simple structure, reliable operation, large measurement range, high measurement accuracy, not affected by viscosity, and can be transmitted remotely. However, due to the important component of the measuring part being aluminum alloy, the rotary piston flowmeter can only measure non corrosive or slightly corrosive liquids, such as heavy oil and other petroleum products. The rotary piston flowmeter consists of a flow transmitter and a counting mechanism. Installing a radiator between the transmitter and the counting mechanism constitutes a high-temperature flowmeter. The transmitter consists of a measuring chamber equipped with a pair of elliptical gear rotors and a sealed coupling, while the counting mechanism includes a reduction mechanism, an adjusting mechanism, a counter, and a transmitter.

The measuring room is composed of a pair of elliptical gears and a cover plate to form a crescent shaped cavity as the unit of measurement for flow rate. The pressure difference between the inlet and outlet of the rotary piston flowmeter drives it to rotate, continuously measuring the liquid through the crescent shaped cavity and sending it to the outlet. The liquid flowing through each rotation is four times that of the crescent shaped cavity. The total number of rotations and the speed of rotation of the elliptical gear are transmitted to the counting mechanism or transmitter through a sealed coupling, which can determine the total amount and instantaneous flow rate of the liquid passing through the pipeline.

There are some principles that need to be met when selecting a rotary piston flowmeter. So, what principles should be met? Let's learn together! actuallyRotating piston flowmeterGenerally, meeting two requirements is sufficient for selection, mainly:

Firstly, when selecting a rotary piston flowmeter, the relationship between the diameter and range must be considered. Although the range of the rotary piston flowmeter can be set arbitrarily according to requirements, the range that can be set is correspondingly limited by the measured diameter. There is an important principle here, which is to consider when setting the measurement range. Only when the normal flow rate exceeds half of the full range can the measurement accuracy reach its maximum. The flow rate can generally be selected between 2 and 4 rn/s. If the medium wears the electrode or flows by itself due to the potential difference of the high-level groove, a slightly lower flow rate can be chosen; If the medium is easy to adhere to, a relatively high flow rate can be chosen. After comprehensive consideration, select the diameter of the instrument based on the flow meter.

Secondly, the fluid being measured must be a conductive liquid or slurry, and its conductivity should not be less than 5~S/cm. The fluid being measured should not contain a large amount of ferromagnetic substances or bubbles; The rotary piston flowmeter should select the corresponding lining material, electrode material, pressure rating, and instrument structure form based on the corrosiveness, working pressure, wear resistance, temperature, and other characteristics of the measured fluid.

The principles to be achieved in the selection of rotary piston flow meters can be found in your purchaseRotating piston flowmeterAs a reference for you, thank you for your attention!