SB--7--626 Page 9
SECTION 4
OPERATION
Future operating problems can be avoided if proper
precautions are observed when the equipment is first
put into service.
Before starting under power, the blower should be
turned over by hand to make certain there is no binding,
or internal contact.
Each size blower has limits on pressure differential,
running speed, and discharge temperature which must
not be exceeded. These limits are shown in “Maximum
Operating Limitations”, FIGURE 9, page 10.
Operating beyond the specified oper-
ating limitations will result in damage
to the unit.
It is important that the pressures and temperatures are
measured directly at the ports of the blower to avoid
error that may be caused by intervening pipe runs,
fittings, etc.
Relief valves must be used to protect against excessive
pressure or vacuum conditions. These valves should
be tested at initial startup to be sure they are adjusted
to relieve at or below the maximum pressure differential
rating of the blower.
Relief valves should be placed as
close as possible to the blower inlet
or discharge.
In some instances, pressure may be relieved at a lower
point than the blower maximum in order to protect the
motor or the equipment served by the blower.
LIMITATIONS
For information regarding limitations, refer to “Maxi-
mum Operating Limitations,” FIGURE 9, page 10.
Do not operate equipment without
adequate silencing devices installed
since high noise level may cause
hearing damage. (Reference OSHA
standards.)
After the unit has been started, the load should be ap-
plied gradually. A blow--off valve for unloaded starting
is recommended.
The first few minutes of operation are the most critical,
in so far as potential problems are concerned, so all
equipment should be observed closely for excessive
heat, noise or vibration during this period. Speeds,
pressures, temperatures, vacuums and other operat-
ing conditions should be checked to insure that speci-
fied limits are not exceeded. See FIGURE 9, page 10.
ROUTINE OPERATION
Since the unit is a positive displacement type, the
volume flow is fixed for constant speed so no regulation
can be achieved by restricting the pipe or adjusting the
valves. Excess air flow may be discharged through a
relief valve or blow--off to atmosphere. Volume flow is
essentially proportional to the speed and this offers a
method of flow adjustment with V--belt driven
machines.
Although these units are extremely rugged and are
designed with adequate factors of safety, it is possible
to cause serious damage by exceeding the manufac-
turer’s limits.
Periodically the gauges, instruments, and safety
devices used to monitor the blower should be checked
for calibration and functioning.