When handling fluids, one of the more simple means of doing so involves a shuttle valve. This specific type of valve has a simple function. It also comes in different types for various applications. One readily available kind is the pneumatic shuttle valve.
What Are Shuttle Valves?
A shuttle valve often called a double check valve, is called an OR logic element. In this specific device, one or the other input becomes the output. Its structure is simple, consisting of:
- One tube with three separate openings (front end, middle and back end)
- A free flowing blocking element within the tube often a ball
- Leak-tight sealing
The process of operation is also simple. Fluid pressure on one end pushes the ball or blocker towards the opposite end. This motion prevents the fluid from escaping from the opposite end while allowing it to flow through the opening in the middle of the tube. This overall configuration allows fluid to push in from two diverse sources while preventing back flow of one inlet source into the other.
Applications of the Pneumatic Shuttle Valve
Shuttle valves are for application mostly in pneumatic and rarely in hydraulic systems. The structure of pneumatic shuttle valves is necessary for dual-input pilot control. These valves automatically select the higher of the two pressure points. This type of shuttle valve has several applications. The major uses are:
- Heavy Industrial Machinery: Allows the operation of more than one switch on a single machine
- Winch Brake Circuit: In instances where there is a pneumatic winch, the pneumatic shuttle valve delivers brake control
- Air Pilot Control: Helps to lock the cylinder in the designated position
- Instrumentation and Pressure Cables: As part of standby and emergency systems, the shuttle valve will shift and take over if the compressor fails. After the reestablishment of the compressor pressure, the pneumatic shuttle valve shifts back re-establishing a seal of the standby system
Such applications stress the importance of this valve.
