Goulds Pumps 3408 - IOM - Manual (Page 32)

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3408 IOM 03/99
In installations with moderate temperature changes,
low humidity, and a clean atmosphere, the oil should
be changed after approximately 1000 hours of
operation. The oil should be inspected at this time to
determine the operating period before the next oil
change. Oil change periods may be increased up to
2000-4000 hours based on an 8000 hour year. Check
the oil frequently for moisture, dirt or signs of
“breakdown”, especially during the first 1000 hours.
▲
! CAUTION
Do not over oil; this causes the bearings to run
hot. The maximum desirable bearing housing
operating temperature for all ball bearings is
180° F. Should the temperature of the bearing
frame exceed 180° F (measured by
thermometer) shut down pump to determine
the cause.
COUPLING LUBRICATION
Flexible couplings (Wood’s Sure-Flex or Falk Torus
coupling for instance) provide smooth transmission of
power. There is no rubbing action of metal against
rubber to cause wear. Couplings are not affected by
abrasives, dirt or moisture. This eliminates the need
for lubrication or maintenance, and provides clean
and quiet performance.
If other type couplings are used, follow maintenance
instructions of coupling manufacturer.
SEALING INFORMATION
PACKING (NON-ASBESTOS)
On packed pumps the packing is installed prior to
shipment. All packings used are the highest grade
material. Before pump is put into operation check the
condition of the packing. If pump is installed within sixty
(60) days after shipment the packing will be in good
condition with a sufficient supply of lubrication. If pump is
stored for a longer period it may be necessary to repack
the stuffing box. In all cases, however, we recommend an
inspection of the packing before pump is started.
The standard 3408 pump packing is made from braided
acrylic yarn impregnated with graphite.
A soft, well-lubricated packing reduces stuffing box
resistance and prevents excessive wear on the shaft or
shaft sleeve. Many brands of packing on the market have
the desired qualities. Standard packing is John Crane
Style 1340, or equal.
When a pump with fiber packing is first started it is
advisable to have the packing slightly loose without
causing an air leak. As the pump runs in, gradually tighten
the gland bolts evenly. The gland should never be drawn
to the point where packing is compressed too tightly and
no leakage occurs. This will cause the packing to burn,
score the shaft sleeve and prevent liquid from circulating
through the stuffing box cooling the packing. The stuffing
box is improperly packed or adjusted if friction in the box
prevents turning the rotating element by hand. A properly
operated stuffing box should run lukewarm with a slow
drip of sealing liquid. After the pump has been in
operation for some time, and the packing has been in
operation for some time, and the packing has been
completely run-in, drippage from the stuffing boxes should
be at least 40 to 60 drops per minute. This will indicate
proper packing and shaft sleeve lubrication and cooling.
NOTE: Eccentricity of the shaft or sleeve
through the packing could result in excess
leakage that cannot be compensated for.
Correction of this defect is very important.
Packing should be checked frequently and replaced as
service indicates. Six months might be a reasonable
expected life, depending on operating conditions. It is
impossible to give any exact predictions. A packing tool
should be used to remove all old packing from the stuffing
box. Never reuse old and lifeless packing or merely add
some new rings. Make sure the stuffing box is thoroughly
cleaned before new packing is installed. Also check the
condition of the shaft or sleeve for possible scoring or
eccentricity, make replacements where necessary.
New packing (non-asbestos) should be placed carefully
into the stuffing box. If molded rings are used, the rings
should be opened sideways and the joints pushed into
the stuffing box first. The rings are installed one at a time,
each ring seated firmly and the joints staggered at about a
90° rotation from each preceding joint.
If coil packing is used, cut one ring to accurate size with
either a butt or mitered joint. An accurately cut butt joint is
superior to a poor fitting mitered joint. Fit the ring over the
shaft to assure proper length. Then remove and cut all
other rings to the first sample. When the rings are placed
around the shaft a tight joint should be formed. Place the
first ring in the bottom of the stuffing box. Then install
each succeeding ring, staggering the joints as described
above, making sure each ring is firmly seated.