Air or vapor given off or expelled as a byproduct or result of an operation or
treatment process.
Oil aerosol
A suspension of fine solid or liquid particles in a gas.
Oil bath filter
A labyrinth type filter having the active surfaces
continuously splashed with oil. Most pollutants are absorbed by
the oil which when circulated releases its pollutants, which sink
by gravity to the bottom of the oil pan.
Oil free compressor
A positive displacement air compressor which has no oil
injected into the compression chamber for lubrication, cooling or
sealing
Oil system
Consists of a vessel which is a combination of oil sump and
oil separator, an oil cooler and an oil filter.
Operating pressure
The gauge pressure at which a pressure vessel is maintained in
normal operation.
Operating pressure
burst
Above this pressure, the system may rupture or burst.
Orifice
An opening such as a hole or vent. An opening through which
air can pass, or a restricted opening placed in a pipe line to
provide a means of controlling or measuring flow.
OSHA
Occupational Safety and Health Administration.
Overhung
type centrifugal compressor
A single inlet compressor with the impeller or impellers
mounted on an extended shaft of the driver.
Overpressure
accumulation
The permitted increase in pressure developed after the valve
has opened. Usually expressed in percentage, ie.; 3% accumulation
(A.S.M.E. Code, Section I). Flows through safety/relief valves are
officially determined at these overpressure conditions.
