G400 Rotary piston meter

The RABO rotary piston CN114.7 gas meters are characterized by their wide measuring ranges and compact dimensions. They ensure high accuracy even with low and irregular flow.

Principle of operation

Rotary piston gas meters are volumetric meters for gaseous media which work on the principle of the displacement of defined quantities of gas. Thanks to the volumetric measurement, they operate independently of the influences of the installation and are therefore particularly suitable for compact measuring systems with short straight inlet sections. They measure the gas volume under operating conditions and are approved for custody transfer measures. Where required, they can be combined with a volume converter for measurement at the basic reference conditions.

Measurement process

In the casing, or body of the meter, which constitutes the measurement chamber, equipped with a gas inlet and outlet section, there are two rotating pistons, the section of which looks like that of an eight (8). They are connected to each other by synchronizing gear wheels. When the gas flows, the pistons rotate without contact with each other and deliver a constant and repeatable quantity of gas at the outlet, called the cyclic volume. A complete rotation of the system therefore corresponds to the passage of a given volume of gas. The rotary movement of the pistons is transmitted to the mechanical totalizer by means of a reduction box and a magnetic coupling. The measurement error calibration of rotary piston gas meters is done by means of a pair of gear wheels in the totalizer. Operating principle of rotary piston gas meters