result in failure of the valve itself. If blower capacity appears to
be too low. refer to the TROUBLE SHOOTING CHECKLIST
first. If no help is found there it may be possible to increase
the blower speed. Before attempting this change. contact the
nearest Distributor for recommendations. Be prepared to
furnish data on actual air requirements and operating
For equipment covered specifically or indirectly in this
instruction book, it is important that all personnel observe
safety precautions to minimize the chances of injury. Among
many considerations. the following should particularly be
n Blower casing and associated piping or accessories may
become hot enough to cause major skin burns on contact.
n Internal and external rotating parts of the blower and
driving equipment can produce serious physical injuries.
Do not reach into any opening in the blower while it is
operating, or while subject to accidental starting. Cover
external moving parts with adequate guards.
n Disconnect power before doing any work and avoid
bypassing or rendering inoperative any safety or protective
n If blower is operated with piping disconnected, place a
strong coarse screen over the inlet and avoid standing in
the discharge air stream.
n Stay clear of open inlet piping (suction area) of pressure
blowers, and the open discharge blast from vacuum
n Stay clear of the blast from pressure relief valves and the
suction area of vacuum relief valves.
n Avoid extended exposure in close proximity to machinery
which exceeds safe noise levels.
n Use proper care and good procedures in handling, lifting,
installing, operating and maintaining the equipment.
n Casing pressure must not exceed 25 PSI 0l72 kPa) gauge.
Do not pressurize vented cavities from an external source,
nor restrict the vents.
n Do not use air blowers on explosive or hazardous gases.
n Other potential hazards to safety may also be associated
with operation of this equipment. All personnel working in
or passing through the area should be warned by signs
MAINTENANCE & REPLACEMENTS
A good program of inspection and maintenance servicing,
followed consistently, is the most reliable method of minimizing
repairs to a blower. A simple record of services and dates will
help keep this work on a regular schedule. Basic service
needs are lubrication. checking for hot spots or increase in
vibration and noise and the recording of operating pressures
and temperatures. Above all. a blower must be operated
within its specified rating limits, to obtain satisfactory service
A newly installed blower should be checked frequently during
the first month of full-time operation. Attention thereafter may
be less frequent. depending on what the early checks have
consideration. Unless operating conditions are unusually
severe, a weekly check of oil levels in the gearbox, with
addition of oil as required. should be sufficient. Complete oil
changes should be made at intervals of 1000 operating hours,
or more frequently if oil condition becomes poor.
Driver lubrication practices should be in accordance with the
manufacturers instructions. If direct connected to the blower
through a lubricated type coupling. the coupling should be
checked and greased each time blower oil is changed. This
will help reduce wear and prevent it from causing vibration. In
a belted drive system. check belt tension periodically and
inspect for frayed or cracked belts. Refer to tensioning
instructions under INSTALLATION.
In a new and properly installed blower there are no moving
contacts between the two impellers. or between the impeller
and cylinder or headplates. Wear is then confined to the
bearing which support and locate the shafts, the shaft seals,
and the timing gears. All are lubricated, and wear should be
nominal if clean oil of the correct grade is always supplied.
Seals are subject to deterioration as well as wear, and may
require replacement at varying periods.
Shaft bearings have been selected to have optimum life under
average conditions with proper lubrication. They are critical in
the service life of the blower. Gradual bearing wear may allow
a shaft position to change slightly. until rubbing develops
between impeller and cylinder headplate. This will cause spot
heating, which can be detected by feeling these surfaces.
Sudden bearing failure is usually more serious. Since the
shaft and impeller are no longer supported and properly
located, extensive general damage to the blower casing and
gears is likely to occur.
Shaft seals should be considered expendable items. to be
replaced whenever drainage from the headplate vent cavity
becomes excessive or when the blower is disassembled for
any reason. Sealing effectiveness can vary considerably from
seal to seal and is also affected by shaft smoothness under
the seal lip. Because of these normal variables, minor seal
leakage should not be considered an indicator for seal
Timing gear wear. when correct lubrication is maintained
should be negligible over a period of years. Gear teeth are cut
to provide the correct amount of backlash, and gears correctly
mounted on the shafts will accommodate