All rotary piston meters, commonly known as rotary meters, utilize the fundamental 1846 lobed impeller design of the Roots brothers. Originally designed for water pump applications, this fundamental style has been parent to virtually all interweaving rotor designs applied to gas and liquid compression, pumping and measurement applications. The first positive displacement rotary meters manufactured for gas applications were built in 1920.
Over time, rotary meters have been continually improved by use of new modular designs, better materials, more precise manufacturing processes and electronics. They have a proven record of accomplishment of high and consistent performance. As compared to orifice, diaphragm and turbine meters. They have better accuracy, larger turndowns and are relatively smaller than other mechanical gas meters.
This paper generally describes the fundamental concepts of rotary meters, installation and maintenance.