Air Flow; Oil System - Atlas Copco XAHS 146 Dd S3B APP Instruction Manual

Reference Name
SC Safety Cartridge
SL Scavenge Line
SV Safety Valve
TS Temperature Sensor
UA Unloader Assembly
VI Vacuum Indicator
VV Vacuator Valve
WPG Working Pressure Gauge

AIR FLOW

The system comprises:
AF Air filter
AR/OS Air receiver/oil separator
CE Compressor element
UA/UV Unloader assembly with unloader valve
BDV Blow-down valve
LV Loading valve
Air drawn through the airfilter (AFce) into the
compressor element (CE) is compressed. At the
element outlet, compressed air and oil pass into the air
receiver/oil separator (AR/OS).
The check valve (CV) prevents blow-back of
compressed air when the compressor is stopped. In
the air receiver/oil separator (AR/OS), most of the oil
is removed from the air/oil mixture; the remaining oil
is removed by the separator element.
The oil collects in the receiver and on the bottom of
the separator element.
The air leaves the receiver via a minimum pressure
valve (MPV) which prevents the receiver pressure
from dropping below the minimum working pressure
(specified in section Limitations), even when the air
outlet valves are open. This ensures adequate oil
injection and prevents oil consumption.
The system comprises of a temperature switch (TS)
and a working pressure gauge (WPG).
A blow-down valve (BDV) is fitted in the unloader
assembly to automatically depressurise the air
receiver (AR) when the compressor is stopped.
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OIL SYSTEM

The system comprises:
AR/OS Air receiver/oil separator
OC Oil cooler
OF Oil filter
The lower part of the air receiver (AR) serves as an oil
tank.
Air pressure forces the oil from the air receiver/oil
separator (AR/OS) through the oil cooler (OCce) and
oil filter (OF) to the compressor element (CE).
The compressor element has an oil gallery in the
bottom of its casing. The oil for rotor lubrication,
cooling and sealing is injected through holes in the
gallery.
Lubrication of the bearings is ensured by oil injected
into the bearing housings.
The injected oil, mixed with the compressed air,
leaves the compressor element and re-enters the air
receiver, where it is separated from the air as
described in section Air flow. The oil that collects on
the bottom of the oil separator element is returned to
the system through a scavenging line (SL), which is
provided with a flow restrictor (FR).
The oil filter by-pass valve opens when the pressure
drop over the filter is above normal because of a
clogged filter. The oil then by-passes the filter
without being filtered. For this reason, the oil filter
must be replaced at regular intervals (see section
Preventive maintenance schedule).