How do Hydraulic Bypass Valves Function?

Posted on December 10, 2019 Michael Jones Aerospace Parts

Hydraulic systems are a widely used, reliable, and cost effective method of creating motion and actuation for various components. They can be utilized for car braking systems, aircraft flight control systems, industrial machinery, and much more. Simply put, hydraulic systems work by pressurizing liquid in an enclosed space, which in turn transfers that pressure equally through the system which can be used to perform various tasks. With hydraulics, it is important that that pressure remains equal and there is a backup in case of leakage or failure. To prevent and solve this problem, many hydraulic systems utilize hydraulic bypass valves.

Hydraulic bypass valves work to maintain equal amounts of pressure within the hydraulic system. This is achieved through the use of a piston and spring that work together to divert or bypass fluid when needed. Normally, the piston remains closed and the fluid flows normally while there is equal pressure in the inlet and outlet of the spring. When one side begins to build up a great amount of unequal pressure, the spring begins to compress, pushing the piston which creates an opening. Fluid is then diverted into this new opening and typically is moved pack to a reservoir or another area of the system.

For example, in the case of a car braking system, the hydraulic bypass valve works to ensure the braking system does not fail in case of leaking or damage. Cars often rely on their front brakes for stopping power, and leakage can cause them to fail through a loss of fluid pressure. Hydraulic pressure in this case becomes uneven and the bypass valve redirects brake fluid to the back brakes to allow for safe stopping. Hydraulic bypass valves are seen in many other systems in which water and oil is utilized for actuation and creating motion, as well as they are always useful for maintaining safe and equal pressurization.