Control valve controller

Automatic operation means to adjust the controlled variable.
Enthalpy: a thermal dynamic quantity, which is the internal energy of the body and its volume and pressure of the product, and: H = U + PVO (
Referred to as the heat capacity).
Entropy: a thermal dynamic system can not be converted to a theoretical measure of the energy of mechanical work.
Feedback signal: measuring the direct control variable and the return signal. For locator with a control valve, the feedback signal is typically a mechanical indication of the closure element is connected to the lever position feedback to the locator.pneumatic hand valve
FCI: fluid control organizations.
Usage Frequency response characteristic: the relationship between the frequency-dependent amplitude and phase represented by the steady-state sinusoidal input caused by the basic sinusoidal output. The output of the amplitude and the phase shift can be seen as a function of the input test frequency, and is used to describe the dynamic behavior of the control apparatus.
Hardness: metal resistance to plastic deformation (usually in the ability of the recess form). The resistance of the plastic and rubber tip piercing the ability of its surface.steam solenoid valves