Sullair 20/12 Series Operator's Manual

Section 5
OPERATION
18
5.2 PURPOSE OF CONTROLS
CONTROL OR INDICATOR PURPOSE
PRESSURE RELIEF VALVE (Interstage) Opens inner stage to atmosphere should the pressure
become too high (140 psig [9.7 bar).
NOTE
Under certain conditions, it may be desirable to
pipe the relief valves to theoutside of the building
for inside installation.
TERMINAL CHECK VALVE Prevents line pressure backflow into the sump during
unload conditions and after shutdown.
SULLICON CONTROL Regulates the amount of air allowed to enter the air in-
let valve. This regulation is determined by the amount
of air being used at the service line.
PILOT PRESSURE REGULATOR Opens a pressure line between the sump and Sullicon
Control allowing the Sullicon to regulate air delivery to
air demand.
SOLENOID PILOT VALVE Bypasses the pilot pressure regulator valve causing
the Sullicon Control to close the inlet butterfly valve
when the compressor reaches maximum operating
pressure.
BLOWDOWN VALVE Vents sump pressureto theatmosphere during unload
conditions and shutdown.
PRESSURE SWITCH Senses service line pressure. When line pressure
reaches maximum operating pressure, the pressure
switch signals the solenoid pilot valve to unload the
compressor.
MINIMUM PRESSURE/CHECK VALVE Maintains a minimum pressure of 160 psig (11 BAR) in
the sump. This valve restricts air discharge from the
sump when the pressure falls to 160 psig (11 bar).
However, full flow is allowed at normal operating pres-
sures.
HIGH DISCHARGE TEMPERATURE SWITCH Shuts the compressor down if the discharge tempera-
ture from the first stage exceeds 265ºF (130ºC) or the
second stage exceeds 265ºF (130ºC).
LOW FLUID PRESSURE SWITCH Shuts the compressor down if the fluid pressure down-
stream of the bearing filter drops below 90 psig (6.2
bar).
INLET CYLINDER Holds butterfly valve closed during start mode.
CLOSED INLET SOLENOID VALVE Prevents the inlet cylinder from opening the inlet but-
terfly valve during start-up.
FLUID STOP VALVE SOLENOID VALVE Vents the fluid stop valve solenoid signal upon shut-
down of the compressor.

Sullair 20/12 Series Specifications

General

Brand	Sullair
Model	20/12 Series
Category	Air Compressor
Language	English