PVA 112-2190, Operation Manual, Page: 6 / 34

FCS300 Series Manual
Revision D /
June 2020
Page 6 of 34
System Description
This manual applies to the following Precision Valve & Automation, Inc. valves:
FCS300-F
FCS300-R
Front Closing Stainless Steel Spray Valve, Flat Cap
Front Closing Stainless Steel Spray Valve, Round Cp
FCS300-ES
Front Closing Stainless Steel Spray Valve, Extended Cap
FCS300-ES-ND
FCS300-ES-UF
Front Closing Stainless Steel Spray Valve, Narrow Cap
Front Closing Stainless Steel Spray Valve, Ultra Fine Cap
The valves above will be referred to as the FCS300 Series for the purpose of this manual.
Any information relevant to a specific valve will be indicated.
Theory of Operation
The FCS300 Series is a low pressure, low volume, front closing stainless steel spray valve
that uses air pressure to atomize fluids and transfer them to a substrate. This valve can be
used in a wide variety of coating applications applying low to high viscosity fluids. The
FCS300 Series has a divorced design comprising of two major sections. These include:
•
Air section (red anodized portion)
•
Fluid section
(stainless steel portion)
Air Section
The air section is an aluminum body with a simple piston/cylinder combination used to
open and close the valve. A micrometer adjustment in the upper air body controls how far
the piston and needle assembly can retract thus regulating the rate of fluid flow. The
micrometer will display a distance that the piston and needle will travel.
Fluid Section
The fluid section is a stainless steel body, which includes a needle and seat combination
located at the end of the valve inside the atomizing air cap. Fluid flows through the seat
orifice as the needle retracts out of the seat, then stops as the needle moves back into the
seat. Atomizing air is applied when the needle is retracted to spray all fluid from the air cap.
The micrometer adjustment regulates the distance that the needle can retract out of the
seat thus controlling the orifice size and rate of fluid flow. A precision air regulator is used
to control a precise amount of atomizing air. Fluids can include but are not limited to
solvents, conformal coatings, grease, etc. Wetted parts on the FCS300 Series include: 303,
304 stainless steel, Teflon®, and Kalrez®.