Determination of Turbine Meter Usable Turndown

摘要

It is well known by the users of turbine flow meters that they can be operated over a flow range turndown of up to 100:1 or more. It is also well known that they can be used over a wide range of viscosity by correlating the performance using meter frequency divided by kinematic viscosity, commonly called a "UVC", universal viscosity curve. It is not so commonly known that these two characteristics are somewhat mutually exclusive and not totally inclusive as often used. There are significant limitations to the use of turbine meters over a wide flow range and other limitations to using the "UVC" correlation. The purpose of this paper is to outline these limitations and present a method for determining the usable turndown for a turbine meter in liquid service.