Atlas Copco Standard Pneumatic reserves the right to
alter the configuration of their compressors without notice
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Installation and operating instructions for Directair
compressors
Read all instructions carefully before starting the compressor
1.1 General information
Directair compressors exist in two types, D, which designates
single-stage, and DT, which designates two-stage. The D's
are available 2 through 15 H P and the DT's, 2 through 25 H P.
The D's are built for effective working pressures up to 150 psi
max., and the DT's to 175 psi max. The compressors are
available as power packs, which consist of the compressor
block, motor base, coupling, and motor, and as a complete
tank mounted unit
1.1.1 Operation - D-series
Air is drawn through the intake filter, intake manifold, and
suction discs into the cylinders. The air is compressed, then
discharged through the delivery discs to the temperature
reducer, where the heat of the compressed air Is partly
removed. From the temperature reducer the compressed air is
discharged through the check valve into the tank.
1.1.2 Operation - DT-series
Air is drawn through the intake filter, intake manifold, and into
the low pressure cylinder where it is compressed, then
discharged through the delivery valve to the intercooler, where
the heat from the first stage of compression is removed. The
air then enters the high pressure cylinder through the pulsation
damper and the suction disc where it is further compressed. It
is then discharged through the delivery disc to the cooling caps
of the HP cylinder head and from there to the HP temperature
reducer. It is then discharged through the check valve into the
tank
1.2 Ventilation
The compressor is equipped with a temperature reducer that is
adequate under normal working conditions. Maximizing
ventilation at your installation will reduce condensation and
greatly enhance compressor life and efficiency
Locate compressor in a clean, cool, well ventilated area,
preferably a separate room. DO NOT locate compressor near
toxic fumes, as they may affect compressor operation
If the compressor is placed in a room, it should be of adequate
size to allow for periodic maintenance. The room should have
two openings for ventilation. One opening for intake of cool,
clean outside air, preferably by using a fan (1). If a fan is not
available the minimum size opening (1a) for the intake should
be 1'-6” x 1'-6” and should be placed on the lower portion of
the wall. The other opening (2) allows for exhaust of hot, moist
air, should be 1'-6” x 1'-6” and placed on the upper portion of
the wall. See Drawing "A".
If the compressor cannot be located in a separate room, some
measures should be taken to allow outside air to be drawn in
by the compressor intake. This can be accomplished by using
ductwork (3). The ductwork should be canopied over the
intake, as shown in Drawing "B". The smallest recommended
size of the ductwork opening should be 1'-6” x1'-6”.
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