SHUTTLE VALVE WORKING PRINCIPLE

We were discussing the basics of directional control valve and its classifications in our previous post. We have also seen the working principles and types of check valve.

Today we will see here another type of directional control valve which is termed as shuttle valve.

Shuttle valve will have three port i.e. one common output port and there will be two inlet ports. Figure shows the shuttle valve, source 1 and source 2 are inlet ports and there is also one port which is outlet port.

Shuttle valve working principle

Let pressure at source 1 is P1 and pressure at source 2 is P2. Suppose, pressure P1 is higher than the pressure P2, ball will slide towards the secondary port and will block the source 2. Hydraulic fluid will flow from source 1 to outlet port. If pressure P2 is higher than the pressure P1, ball will slide towards the primary port and will block the source 1. Hydraulic fluid will flow from source 2 to outlet port.

It indicates that shuttle valve outlet port will secure the fluid flow from its inlet port which will be at high pressure. Shuttle valve applications could be seen in load sensing and will secure the flow from higher pressure inlet out of its two inlet port of shuttle valve.

Internal cross section of shuttle valve is displayed here and symbol used for indicating the shuttle valve is also displayed here in following figures.