Working Principle of Pneumatic Actuators
Pneumatic actuators use instrument air pressure to apply force on the diaphragm to move the valve actuator and then to position valve stem. The following photograph shows a cut-away control…
Working Principle of Hydraulic Actuators
Hydraulic actuators use liquid pressure rather than instrument air pressure to apply force on the diaphragm to move the valve actuator and then to position valve stem. Nearly all hydraulic…
Working Principle of Self Operated Valves
Although not a type of actuator itself, a form of actuation worthy of mention is where the process fluid pressure itself actuates a valve mechanism. The self-operating valve principle may…
How Ball Valves Work ?
In the Ball Valve design, a spherical ball with a passageway cut through the center rotates to allow fluid more or less access to the passageway. When the passageway is…
How Globe Valves Work ?
Globe valves restrict the flow of fluid by altering the distance between a movable plug and a stationary seat (in some cases, a pair of plugs and matching seats). Fluid…
How Gate Valves Work ?
Gate valves work by inserting a dam (“gate”) into the path of the flow to restrict it, in a manner similar to the action of a sliding door. Gate valves…
How Diaphragm Valves Work ?
Diaphragm valves use a flexible sheet pressed close to the edge of a solid dam to narrow the flow path for fluid. Their operation is not unlike controlling the flow…
How Sliding Stem Valves Work ?
A sliding-stem valve body is one where the moving parts slide with a linear motion. Some examples of sliding-stem valve body designs are shown here: Sliding Stem Valves Most sliding-stem…
Different Flow Measurement Technologies
Every flow-measuring devices exploits a physical principle to measure the flow rate of fluid stream. Discuss Different Flow Measurement Technologies.
What is an Insertion Flow Meter? – Types, Principle, Advantages
A classic example of an insertion flow meter element is the Annubar, a form of averaging pitot tube. Learn the types and principles.
