Glossary

Quadratic - Its another name for second order, based on form of equation that represents second order response. .

Quick Disconnect - It's a coupling that usually contains at least one check valve that can be rapidly disconnected with minimal leakage. R Rabbet Mount - It's a mounting configuration that utilize matching male and female forms (usually coaxial circular) between cylinder and the mating mounting element. .

Ram - It's a single-acting cylinder where movable element has approximately same cross-sectional area as cylinder bore. Hence, Ram has single diameter type plunger as opposed to piston and rod. The plunger in Ram-type cylinder is also called Ram. .

Ramp Input Function - Its inclined slope, a constantly increasing function, a linear intensification of magnitude. .

Ratchetting - Its stick-slip action (intermittent motion) of control system. .

Rated - It refers to manufacturer's designation of normal operating condition - the allowable, maximum, continuous, etc. .

Ratio of Specific Heats - Its ratio of amount of heat that is required to raise mass of material 1 degree in temperature to amount of heat required for raising an equal mass of reference substance 1 degree in temperature. .

Reciprocation - Its back-and-forth straight line motion or oscillation. .

Redundancy - It's the existence of more than one means for accomplishing given function. .

Regeneration - It's the recovery of energy that would ordinarily be lost. .

Regenerative Control System - It's a system where part or all of output is fed back to help drive function or is stored for driving output converter. .

Reproducibility - It's a quantitative expression of random error that is associated with testers working in different laboratories. The each obtaining single results on identical test material, using same method. That is, precision with which measurement of given quantity can be duplicated in separate facilities. .

Response Time - It's the time required for system output to reach as well as stay within specified percentage of its theoretical final value due to step input - usually equal to five time constants. .

Restrictor - It's the device having reduced fixed or variable area that creates deliberate pressure drop and resistance to normal flow of fluid. Variable types are pressure-compensated, non-compensated or pressure- and temperature-compensated. .

Reynolds Number - It's the dimensionless ratio of dynamic force due to mass flow to shear stress due to viscosity. .

Remote Power Skid - Some press applications may require that hydraulics be located remotely from press itself. Other applications may preclude power system from being able to be installed at top around crown structure of press. In these cases, power system and even controls may be designed into separate unit that is capable of being placed adjacent to press or away from press.