دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: the number of electrons of an element involved in forming a compound.

n: see thalweg.

n: a device used to control the rate of flow in a line to open or shut off a line completely, or to serve as an automatic or semi-automatic safety device. Those used extensively include the check valve, gate valve, globe valve, needle valve, plug valve, and pressure relief valve.

any of several valves: plug, gate, butterfly, needle, etc., used in oil field operations.

n: in a two-diaphragm, fourchamber diaphragm displacement meter, the linkage that uses the motion from the crank to slide D-shaped valves over the three ported seats to fill and empty the four measurement chambers alternately.

n: a tray installed in an absorber tower or fractionating column, similar to a bubble-cap tray except that the passageways permitting gas flow upward through the tray possess valves that reduce the size of the passages when the flow rate is reduced. Valve trays are more common than bubble-cap trays, because they are more efficient and less expensive.

attraction created by the weak electrostatic forces of distributed charge in a polar molecule. Even though the water molecule as a whole is neutral, the polarity or the molecule leads to attraction between individual molecules from slight negative and pos

n: a substance in the gaseous state that can be liquefied by compression or cooling.

n: the existence of a substance in the gaseous state.

n: see bubble point.

n: the pressure exerted by the vapor of a substance when the substance and its vapor are in equilibrium. Equilibrium is established when the rate of evaporation of a substance is equal to the rate of condensation of its vapor.

the pressure exerted by the gas phase (vaporized liquid) in equilibrium with the system conditions.