User Guide

4 / How the Valve Operates
How the Valve Operates
The 740V Series valve is a normally closed, fail-safe,
adjustable opening needle valve.
The amount of fluid dispensed is determined by length
of time the valve is open; fluid reservoir pressure; output
dispensing tip size; needle stroke; and fluid viscosity.
The 740V Series require 70 psi (4.8 bar) air pressure.
This air pressure acting on the piston ➀ retracts the pis-
ton and needle ➁ from the needle seat ➂, permitting
fluid flow from the output tip adapter ➃. Piston and
needle stroke and fluid flow are controlled by the stroke
control knob ➄.
Once the cycle is complete, air is exhausted back
through the valve controller, ensuring rapid and positive
fluid shutoff.
The 740V Series can be operated in any position with-
out affecting flow. Vibration normally has no effect on
performance. The valve can be moved in and out of dis-
pense position at high-cycle rates (such as a recipro-
cating device installed on a production line) without
affecting dispensing performance.
➂
➀
➄
➁
➃
open
closed