Product Manual

QT/QTS Series Quincy Compressor
50161-108, January 2013 5 3501 Wismann Lane, Quincy Ill. - 62305-3116
SECTION 2 SYSTEM DYNAMICS
Description & Application
QT Series compressors are heavy duty, splash lubricated, air cooled, belt driven
compressors capable of delivering 175 PSIG of compressed air.
QTS Series single stage compressors (capable of delivering 125 PSIG of
compressed air) and vacuum pumps are air-cooled and splash lubricated. See
appropriate parts manual for recommended RPM operating range and pres-
sure. The QTS-3VAC & QTS-5VAC vacuum pumps are approved for sweet
dry natural gas applications. It is the installers responsibility to meet the
appropriate codes and regulations for this type of installation.
Principles of Compression Cycles
Single Stage Compressors
During the downstroke of a single stage compressor, air is drawn through an
intake valve in the head of the compressor and into the cylinder. At the bot-
tom of the stroke, the intake valve closes and air is trapped in the cylinder.
The air is then compressed in the cylinder during the upstroke of the piston.
Total compression, from atmo spheric pressure to the final discharge pressure,
is accomplished in one stroke of the piston.
Two Stage Compressors
During the downstroke of the piston of a two stage compressor, air is drawn
through an intake valve in the head of the compressor into the low pressure
cylinder and compressed during the upstroke of the piston.
The compressed air is then released through a discharge valve in the head
of the compressor to an intercooler (usually finned tub ing) where the heat
resulting from compression is allowed to dissipate. The cooler compressed air
is then drawn into a second compression cylinder, the high pressure cylinder,
for compression to final pressure.
From there the compressed air is released through a discharge valve to an
air receiver tank or directly to a network of compressed air supply lines. In
one revolution of the crankshaft a compression cycle is completed.
Principles of Lubrication Systems
Splash Lubricated Compressors
With each stroke of the compressor, a dipper attached to the bottom of the
connecting rod , dips into an oil bath at the bottom of the crankcase. This
dipper splashes oil throughout the interior of the crankcase, lubricating all
moving parts.
It is important with this system that the correct oil level be maintained. If
the oil level is too high, excessive oil carryover could result. If the oil level is
too low, or the compressor is not operated within the correct RPM range, the
moving parts will not be adequately lubricated.