Page 90 - Pneumatic ebook (2)_draft 13 sept 2021

Dual Pressure Valve (AND Valve)

1. A dual pressure valve is also a 3-ported valve which has has two inlets and one outlet. A dual pressure valve requires two
pressurised inputs to allow an output. When compressed air enters through port A, the spool will lock and no path for the
air flow to output. Same thing applies when compressed air is supplied through port B. To enable the output X, both port A
and B need to supply with compressed air.

2. This valve is also called as AND valve because port X only able to produce output if both ports A and B applied with
compressed air.

3. Another name for AND function is interlock control. This means control is possible only when two conditions are satisfied.

Truth table for AND valve
Dual pressure X X Input A Input B Output X
valve A B A B
1 1 1
X
1 0 0
A B
0 1 0

Symbol of dual Cross sectional view of dual 0 0 0
pressure valve pressure valve

INTRODUCTION TO PNEUMATIC SYSTEM 40