# API MPMS 22.2:2005 pdf download

API MPMS 22.2:2005 pdf download.Manual of Petroleum Measurement Standards Chapter 22-Testing Protocol Section 2—Differential Pressure Flow Measurement Devices.

2.0 Definitions and Specific Terms

The definitions are given to emphasize and clarify the particular meaning of terms as used in this document.

2.1 meter: A meter is the assembly of a primary element, a differential producer holder with the upstream and downstream meter tubes that will generate a differential pressure when placed in a flow stream. The differential pressure is monitored by secondary device(s) (section 2.6) to derive the flow rate.

2.1.1 meter asymmetry: Meter asymmetry refers to the orientation of specific items in the meter in this document. For example, it may refer to the position of the differential tap holes, or the orientation of supports within the meter which are not symmetrically placed throughout the diameter.

2.2 primary element or differential producer: The primary element is defined as the differential producer when placed in a flowing stream.

2.3 differential producer holder: The differential producer holder is defined as a pressure containing piping element used to contain and position the differential producer and its associated differential pressure sensing taps in the piping system. An orifice fitting would be an example of such a device.

2.4 meter tube: The meter tube is defined as the straight sections of pipe, including all segments that are integral to the differential producer holder, upstream and downstream of the differential producer and the flow conditioner, if required.

2.5 meter tube internal diameter, D, D1, Dm, or Dr:

In this document it has been assumed that the meter tube is circular. If the meter is used in a non-circular cross-sectional flow line or a non-circular device is installed in a circular flow line, the manufacturer of the device must explain how the critical dimensions of the primary element would be defined and calculated. In addition, other necessary or critical upstream and downstream flow conduit geometry and dimensions for the non-circular differential pressure producing flow measuring device must be defined by the manufacturer.

The published meter tube internal diameter (D1) is the inside diameter as published in standard piping handbooks. This internal diameter is used for determining the required meter run length (e.g., for orifice meters as stated in Tables 2— 7 and 2—8 of API MPMS Chapter 14.3 Part 2, ‘Specification and Installation Requirements”).

The measured meter tube diameter (D,) is the average inside diameter of the upstream section of the meter tube measured at a distance from the primary element as defined by either a published standard or by the meter’s design and at the temperature of the meter tube (T,) at the time of the internal diameter measurements. For example, an orifice diameter is measured at one inch upstream of the orifice plate. The meter manufacturer must define how D1 is obtained and utilized to calculate the flow rate for that meter.

The calculated meter tube internal diameter (D), if used, is the inside diameter of the upstream section of the meter tube computed at flowing fluid temperature (T1). The calculated meter tube internal diameter, D, is used to determine the diameter ratio or B, if applicable, and in the Reynolds Number calculations.

The reference meter tube internal diameter (Dr) is the inside diameter of the upstream section of the meter tube calculated at the reference temperature (Tr). The reference diameter, D, is the certified meter tube internal diameter, as described in the orifice meter document API MPMS Chapter 14.3 Part 2,

2.5.1 area (m) and/or diameter ratio, B: The area ratio, in, is the minimum unrestricted area at the primary element divided by the cross-sectional area of the meter tube.

The area ratio has been simplified to a diameter ratio (B) for orifice and Venturi meters where the bore diameter of the primary element is simply divided by the meter tube internal diameter and is the square root of the actual area ratio.

2.6 secondary devices: Secondary devices required for determining the flow through the primary element, which typically includes monitoring differential pressure and the sensors defining the flowing conditions and fluid properties (pressure, temperature, density, etc.). Differential pressure transmitters are sensitive to mounting position orientation. To minimize the effects of orientation, the transmitter must be zeroed after installation.