Page 87 - Pneumatic ebook (2)_draft 13 sept 2021

Shuttle Valve (OR Valve)

1. Shuttle valve is a three-ported valve which has two inlets and one outlet. When compressed air enters port 12,
the poppet will be pushed to port 14 and it is blocked, thus compressed air flows from port 12 to port 2.

2. This valve is also called as OR valve because port 2 able to produce output, if the compressed air is applied
to either port 12 or 14.

3. A shuttle valve may be used, when the cylinder or valve is to be actuated from two points, which may be
remote from one another.
Truth table for OR valve

Shuttle valve Input 12 Input 14 Output 2

0 0 0
2
1 0 1

0 1 1
12 14
1 1 1
Cross sectional view of shuttle valve
Symbol of shuttle valve Click here to watch working
principle of OR valve

INTRODUCTION TO PNEUMATIC SYSTEM 39