Goulds Pumps HS - IOM - Manual (Page 17)

HS IOM 5/08
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STUFFING BOXES
In the conventional stuffing box, mechanical seals and
packing seal between the stationary and rotating
components of the pump. Generally a clear liquid such
as water is forced through the stuffing box to lubricate
the sealing elements. The lubricating liquid pressure
must exceed the pressure of the pumpage at the
stuffing box. For end suction pumps, lubricating liquid
pressure should be 10-15 PSIG higher than the
discharge pressure. For side and double suction
pumps, lubricating liquid pressure should be between
10-15 PSIG higher than the suction pressure.
NOTE: To determine suction or discharge pressure,
use gauge pressure only.
The piping supplying the lubrication liquid should be
fitted tightly to prevent air from entering. On suction
lifts, a small quantity of air entering the pump at this
point may result in loss of suction.
Lubrication liquid pressure is controlled by a valve on
the outlet piping. Since the liquid leaking from the
stuffing box should be clear, control of the packing
lubricant will vary with the condition of the packing.
Increase pressure within the stuffing box by closing
outlet valve. Adjustments should be slow and
consistent with the run-in procedure for new packing.
The lubricating liquid must be clean, free of grit and
acid. Shaft sleeve scoring, packing destruction, and
mechanical seal face damage will result from
contaminated lubricant.
1. Packing Original equipment packing is a suitable
grade for the service intended. To replace original
packing, contact local packing suppliers.
Refer to Bill of Material and Assembly Drawing
(Fig.W14) for specific packing size and configuration.
2. Packing Procedure
a. Stuffing box and shaft sleeve must be clean and free
of grit.
b. Form packing over shaft or mandrel of same
diameter. Carefully cut to packing length. Discard
rings cut too short.
c. Pre-form each ring by coiling 1-½ turns.
d. To install packing rings, do not pull straight.
Expand the coil as a coil spring (See Fig. W13).
e. Expand first coil as shown and insert into stuffing
box. Tamp packing to stuffing box shoulder firmly
with the gland. Note where the cut is positioned.
f. Install second and third coils as required by
assembly drawing, staggering the cut 90°F-120°F.
g. Insert seal cage (lantern ring) into stuffing box,
carefully noting its proper position on assembly
drawing. Failure to properly locate seal cage will
result in insufficient packing lubrication. Packing
and shaft sleeve damage will occur.
h. After packing and seal cage are properly installed,
insert gland into stuffing box. Tighten gland nuts
finger-tight only. Shaft should turn freely.
i. Follow pump start-up procedure. Turn on stuffing
box lubricating liquid and start pump.
j. A significant amount of lubricating liquid should
leak from gland side of stuffing box. Operate pump
for at least 15 minutes before tightening gland nuts.
Make small, even gland nut adjustments to reduce
leakage. Allow adequate run-in time between
adjustments. Acceptable leakage is 30-50 drops per
minute.
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