Pneumatic actuator Pneumatic actuator A pneumatic control valve actuator converts energy (typically in the form of compressed air) into mechanical motion. The motion can be rotary or linear, depending on the type of actuator. A Pneumatic actuator mainly consists of a piston or a diaphragm which develops the motive power. It keeps the air in the upper portion of the cylinder, allowing air pressure to force the diaphragm or piston to move the valve stem or rotate the valve control element. Valves require little pressure to operate and usually double or "triple" the input force. The larger the size of the piston,
Energy ignoring all chemical, electrical, nuclear, and gravitational forces, effects such as advection of any form of energy other than heat and pV-work. The general formulation of the first law (i.e., conservation of energy) is valid even in situations in which the system is not homogeneous. For these cases the change in internal energy of a "closed" system is expressed in a general form by where formula_23 is the heat supplied to the system and formula_24 is the work applied to the system. The energy of a mechanical harmonic oscillator (a mass on a spring) is alternatively kinetic and potential. At