scope:

This manual is intended to be the primary reference source for the calculation and determination of the quantity of ethylene delivered or purchased by. It is assumed that the reader is familiar with measurement terminology and has had a general exposure to gas measurement theory and metering installations.

All procedures in this manual are based upon established standards and other generally accepted industry practices. These standards are listed in the references section of this manual.

This manual covers the application of concentric orifice meter with flow computers or circular charts. Turbine meters and vortex meters are also addressed.

Care should be taken in all phases of handling the measurement equipment and associated records. For details of generally accepted practices, reference is made to the American Gas Association Gas Measurement Manual.

Operating conditions at the measurement site should be selected to insure that the flowing stream is always in the gas phase and free of pressure pulsations such as those associated with pumping. It is recommended that every effort be made to avoid operating at the critical conditions of ethylene. Specifically, this would preclude operating at conditions where the density of ethylene changes very rapidly thus making the measurement of pressure and temperature critical (see Figure 1).