Details of volumetric flow meters

Positive displacement flow meters, also known as fixed displacement flow meters or PD flow meters, are the most accurate type of flow instruments. It uses mechanical measuring elements to continuously divide the fluid into a single known volume part, and measures the total volume of the fluid based on the number of times the measuring chamber repeatedly fills and discharges that volume part of the fluid.
Volume flow meters can be classified into elliptical gear flow meters, scraper flow meters, double rotor flow meters, rotary piston flow meters, reciprocating piston flow meters, disc flow meters, liquid sealed rotary cylinder flow meters, wet gas meters, and membrane gas meters according to their measuring components.
Advantages:
(1) High measurement accuracy;
(2) The installation of pipeline conditions does not affect the measurement accuracy;
(3) Can be used for measuring high viscosity liquids;
(4) Wide range;
(5) The direct reading instrument does not require external energy and can directly obtain the cumulative total amount, which is clear and easy to operate.
Disadvantages:
(1) The results are complex and bulky;
(2) The type, diameter, and working state of the tested medium have significant limitations:
(3) Not suitable for high and low temperature situations;
(4) Most instruments are only suitable for clean single-phase fluids;
(5) Generate noise and vibration.
Application Overview:
Volume flow meters, differential pressure flow meters, and float flow meters are among the three most commonly used types of flow meters, and are often used for measuring the total amount of expensive media such as oil and natural gas.
In 1990, the production volume (excluding household gas meters) was 340000 units, with elliptical gear and waist wheel types accounting for 70% and 20% respectively