Obliteration - A process producing an obstructed flow path choked off by obliterants (polar materials such as water, long chain polymers and silica) that are attracted to the walls of the flow passage.
Omega Rating - A standard method of expressing the tolerance or
sensitivity of a hydraulic component to contaminants in the hydraulic fluid.
The OMEGA value corresponds to the Beta-Ten value of the filtration system
needed to protect the pump for 1000 hours of service at rated conditions.
Open Loop Circuit - A hydraulic circuit in which there is no
automatic feedback to the control input signal.
Operating Conditions - Operating conditions such as temperature and
pressure numerical values relating to any given specific application of a
unit. These may change during the course of operations.
Optimal Control System - A system where the control process is
manipulated according to a "performance index" defined by the
Ordinary Differential Equation - A differential equation which
expresses the response of a system with respect to a single independent
O-Ring - A type of seal consisting of an elastomer in the shape of a
toroid or donut. It is normally mounted in a groove in a manner that the
effectiveness of sealing increases with pressure.
Overshoot - The exceeding or surpassing of a target value as
operating conditions change.
Oxidation Stability - Ability of substance to withstand chemical
reaction with oxygen/air and subsequent degradation. A factor of prime
importance in high temperature operation.