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The pressure at which the control pilot relieves is the functional set pressure of the PORV. When the pilot valve reaches set pressure it opens and releases the pressure from the dome. The piston is then free to open and the main valve exhausts the system fluid. The control pilot opens either to the main valve exhaust pipe or to atmosphere ...
Air pilot control: converting from air to oil results in locking of the cylinder. Shifting the four-way valve to either extreme position applies the air pilot through the shuttle valve, holding the two air-operated valves open and applying oil under air pressure to the corresponding side of the cylinder. Positioning a manual valve to neutral ...
Tilting-disc inconel check valve Check valve symbol on piping and instrumentation diagrams. The arrow shows the flow direction. Vertical lift check valve. A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. [1]
A pilot valve is a small valve that controls a limited-flow control feed to a separate piloted valve. Typically, this separate valve controls a high pressure or high flow feed. Pilot valves are useful because they allow a small and easily operated feed to control a much higher pressure or higher flow feed, which would otherwise require a much ...
For instance if the load should not be held by the check valve anymore. Often the foreign pressure comes from the other pipe that is connected to the motor or cylinder. Counterbalance valves are in fact a special type of pilot controlled check valve. Whereas the check valve is open or closed, the counterbalance valve acts a bit like a pilot ...
Surge control. Surge control is the use of different techniques and equipment in a hydraulic system to prevent any excessive gain in pressure (also known as a pressure surge) that would cause the hydraulic process pressure to exceed the maximum working pressure of the mechanical equipment used in the system.
A safety valve is a valve that acts as a fail-safe. An example of safety valve is a pressure relief valve (PRV), which automatically releases a substance from a boiler, pressure vessel, or other system, when the pressure or temperature exceeds preset limits. Pilot-operated relief valves are a specialized type of pressure safety valve.
Electro-hydraulic actuator. Electro-hydraulic actuators ( EHAs ), replace hydraulic systems with self-contained actuators operated solely by electrical power. EHAs eliminate the need for separate hydraulic pumps and tubing, because they include their own pump, [ 1] simplifying system architectures and improving safety and reliability.