Graco Inc. 309475F - Manual (Page 6)

Introduction
6 309475F
Introduction
A fluid pressure regulator is used in air-assisted spray
systems to ensure accurate, positive control of fluid
pressure to a spray gun, dispensing valve, or atomizing
head.
A regulator installed at a circulating line take-off or pump
reduces main line pressure to maintain the desired fluid
pressure to the spray gun, dispensing valve, or atomiz-
ing head.
Models 233771, 233772, 234268 and 234269 (F IG . 1.)
are mechanically operated back pressure regulators that
limit the supply pressure to a set value by opening an
outlet and guiding back excess material when the prede-
termined pressure has been achieved. These valves are
used in circulating systems.
Models 233767, 233814, 233768, 234260, 234264, and
234265 (F
IG . 2.) are mechanically operated fluid pres-
sure regulators designed primarily for use with low to
medium viscosity fluids.
Models 233760, 233769, 233770, 233813, 234259,
234266, 234270, and 234271 (F
IG . 3.) are pneumati-
cally operated fluid pressure regulators designed pri-
marily for use with highly viscous coatings.
Fig. 1. Cutaway of Mechanical Back Pressure Regulator
TI1770A
Adjustment knob
Spring
Valve plunger
Adjustment knob
Fluid Outlet
(Return line)
Adjustment knob
Fluid Inlet
(From gun)