American Petroleum Institute

Measurement of Liquid Hydrocarbons by Turbine Meter Systems - First Edition; ANSI Z11.299: 1971
 N STD 2534

Annotation

INTRODUCTION

This standard has been prepared as a guide for design, installation, and operation of turbine meter systems in liquid hydrocarbon service. Primary emphasis is placed on the turbine meter and its accessories, but many of the concepts and innovations described are adaptable to other devices concerned with the volumetric measurement of liquid hydrocarbons. For details of specific equipment previously documented by the American Petroleum Institute, refer to API Standard 1101: Measurement of Petroleum Liquid Hydrocarbons by Positive Displacement Meter (ANSI Z11.170-1965). API Standard 2531: Mechanical Displacement Meter Provers (ANSI Z11.171-1965), and API RP 2533: Metering Viscous Hydrocarbons.

The turbine meter has been recognized as an acceptable quantity measuring device for many years; however, its usefulness to the oil industry has become apparent only during the past decade. Improvements to the measuring element and the ever-increasing rates of flow jointly account for vigorous interest in a compact, mechanically simply, long-lived liquid meter.

The turbine meter consists of a rotor or propeller which senses the linear velocity of a flowing stream. The moving liquid imparts a rational or tangential velocity to the rotor which is proportional to rate of flow. The movement of the rotor is detected by mechanical, optical, or electrical means and is recorded on an appropriate readout device.

Turbine meters have typical performance characteristics that are best described by meter performance curves (see Appendix A, Fig. A-1). Principal parameters, such as flow rangeability within tolerable limits of linearity and repeatability, are related to fluid properties (i.e., density, viscosity, and vapor pressure) and to mechanical meter characteristics (i.e., rotor mass, bearing friction, magnetic drag, and wetted area relating to fluid imposed drag on the turbine or rotor).