API MPMS 14.1 2006 pdf free download

API MPMS 14.1 2006 pdf free download.Manual of Petroleum Measurement Standards Chapter 14—Natural Gas Fluids Measurement.
4 Definitions 4.1 absorption: Occurs when natural gas constituents are dissolved into a liquid or solid that is not considered to be the mix- ture’s liquid phase. 4.2 adsorption: Occurs when a thin film of molecules adheres to a liquid or solid surface. 4.3 chilled mirror test: Used to determine dew points (water and/or hydrocarbon) by passing the natural gas over a mirror while gradually reducing the temperature of the mirror until condensation forms. A Bureau of Mines-type of dew point apparatus is commonly used for chilled mirror tests. 4.4 cricondenbar: The point of maximum pressure on a hydrocarbon dew point curve. This is the highest pressure at which a hydrocarbon mixture can exist separately as gas and liquid. 4.5 cricondentherm: The point of maximum temperature on a hydrocarbon dew point curve. The cricondentherm is the highest temperature at which hydrocarbon vapor can condense to form liquid. 4.6 cricondentherm pressure: The pressure at which the cricondentherm occurs on a hydrocarbon dew point curve. 4.7 continuous sampling systems: Provide for an uninterrupted flow of sample. 4.8 de-sorption: Occurs when adsorbed or absorbed molecules are released from a liquid or solid surface. 4.9 extension tube (“pigtail”): A piece of tubing placed on the end of a sample container used to move the point of pressure drop (point of cooling) away from the sample being acquired. 4.10 floating piston cylinder: A container which has a moving piston that has its forces balanced by a pre-charge pressure. 4.11 flow-proportional composite sampling: The process of collecting gas over a period of time at a rate that is propor- tional to the pipeline flow rate. 4.12 gas sample distortion: Any effect that results in a sample that is not representative of the gas stream. 4.13 gas sampling system: The system intended to deliver a representative sample of natural gas from the pipeline to the analytical device.
4.15 hydrocarbon dew point: A temperature at a given pressure at which hydrocarbon vapor condensation begins. 4.16 hydrocarbon dew point curve: A curve connecting all points on a temperature-pressure diagram where a hydrocar- bon vapor begins to condense into liquid. 4.17 lag time in a sample system: The time required for a molecule to migrate from the inlet of the sample probe to the inlet of an analyzer. 4.18 mobile sampling system: The system associated with a portable gas chromatograph. 4.19 multi phase flow: Defined as two or more phases in the stream. 4.20 normal condensation: Caused by an increase in pressure or a decrease in temperature. 4.21 normal vaporization: Caused by a decrease in pressure or an increase in temperature. 4.22 phase: A physical state of a compound (e.g., solid, liquid, or gas). Each phase has a distinct molecular arrangement and can be readily identified (like the two phases of H 2 O in ice water—solid and liquid). 4.23 phase behavior: Refers to the condensation and vaporization characteristics of a hydrocarbon mixture. It includes con- siderations such as temperature, pressure, composition, relative amounts of the liquid and gas phases. 4.24 pitot probe: An impact device with an inlet and return port that provides flow to a hot loop by converting velocity into a differential pressure. 4.25 re-circulation region (“eddy”): An area within a piping system where gas is not continually being replaced even though gas is flowing through the system.
4.26 representative gas sample: Compositionally identical, or as near to identical as possible to the sample source stream. 4.27 residual impurities: Any substances, such as air or natural gas components, that are left in a sample cylinder. 4.28 retrograde condensation: Caused by a decrease in pressure or increase in temperature. 4.29 retrograde vaporization: Caused by an increase in pressure or decrease in temperature. 4.30 sample container: Any container used to hold a natural gas sample. Typical sample containers are constant volume cyl- inders or floating-piston cylinders. 4.31 sample loop: Part of the sampling system that conveys the sample from the probe to the container or analytical device. It is typically external to the analysis device. This should not be confused with the sample loop that is inside an analytical device such as a gas chromatograph. 4.32 sample probe: A device extending through the meter tube or piping into the stream to be sampled. 4.33 sample source: Refers to the stream being sampled. 4.34 sampling separator: A device in the sampling system used to collect free liquids. 4.35 single-phase flow: Natural gas flowing at a temperature above the hydrocarbon dew point and free of compressor oil, water, or other liquid or solid contaminants in the flow stream.