Casing Pedestals
On some models, water cooled pedestals are available. Connection of coolant lines is made in the same
manner as above.
Mechanical Seals
Seal materials (carbon, ceramic, PTFE, etc.) are suitable for use at temperatures to 260°C | 500°F.
(100°C to 121°C | 212°F to 250°F if seal has rubber parts). However, for satisfactory operation, there
must be a liquid film between the seal faces to lubricate them. If the liquid flashes to vapor, the faces will
run dry and be damaged. To prevent this, the liquid must be cool. In general, this requires that the liquid
be cooled so that the vapor pressure is well below the stuffing box pressure. Doubtful cases should be
referred to Goulds for a recommendation. Refer to seal manufacturer's drawing for location of taps.
Some methods which may be used to cool the seal are:
1.
Dead Ended Seal Chamber
No liquid is circulated through the stuffing box. The isolated or "dead ended" liquid around the
seal is cooled by circulating water in the stuffing box jacket, if any.
2.
Cool Liquid Flushing - External Source
A clean, cool compatible liquid is injected from an outside source directly into the seal chamber.
The flushing liquid must be at a pressure 20 to 40 PSI greater than the pressure in the stuffing
box. Onehalf to two GPM should be injected. A control valve and rotometer placed in the inlet line
permits accurate regulation. Cooling water can be circulated through the stuffing box water jacket
(if any) in addition to the external flush.
3.
Cool Liquid Flushing - Product Cooling
In this arrangement, pumped liquid is piped from the pump casing, cooled in an external heat ex-
changer, then injected into the seal chamber. A control valve together with a rotometer and/or a
dial thermometer should be installed in a line from the exchanger to the seal chamber. One-half
to two GPM should be circulated. Cooling water, one to three GPM, should be circulated through
the stuffing box jacket, if any.
5.9 Connection of Drain Piping
All units contain tapped openings around the stuffing box for draining leakage. On corrosion resistant
units, a drain pan is supplied with a tapped opening. Check the assembly dimension print for size and
location.
5.10 Connection of Equalizing Piping
Some multi-stage pumps have equalizing piping to equalize pressure on the stuffing boxes (see
). This piping is in the box of fittings which accompanies the pump. The ends
of the piping must be connected to the openings in each stuffing box.
5.11 Impeller Adjustment
Some end suction pumps, in addition to vertical pumps, have means of adjusting impeller clearance with-
in the casing. The clearance was set at the factory, but in transit, the clearance may have been lost.
Proper clearance must be attained before a pump is operated or serious damage may occur. Check and
reset impeller clearance by method described in
6.3 Impeller Clearance Adjustment on page 53
.
5.9 Connection of Drain Piping
3175 Installation, Operation and Maintenance Instructions
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