Xylem 1580 Series In-Line Mounted Centrifugal Fire Pumps AC2516 REV.B - Manual (Page 6)

6
SERVICE INSTRUCTIONS
1. Close valves on suction and discharge sides of pump. (If
no valves have been installed, it will be necessary to drain
the system).
2. Loosen volute capscrews, do not remove them. Using cap-
screws in the jack screw holes start to remove the pump
assembly from the volute.
3. Remove seal flushing tube, if used.
Remove the volute capscrews and remove the pump
assembly from the volute.
4. Remove the impeller capscrew, lock washer and washer.
Remove the impeller.
STUFFING BOX CONSTRUCTION
WITH PACKING
1. Remove hex nuts from packing gland and remove cover-
plate capscrews. Remove coverplate from bracket.
2. Remove packing rings from the stuffing box.
3. Check condition of shaft sleeve and replace if scored or
otherwise damaged. Note: Replace gasket between sleeve
and impeller as well if damaged.
4. Insert two packing rings in the stuffing box followed by the
lantern ring and then the remaining two pieces of packing.
Make certain that the packing joints are staggered 90
degrees.
5. Install, but do not tighten the packing gland.
6. On the 6x6x9
1 /
2
and the 6x6x11 pumps the volute and
coverplate have rings. Inspect and replace if necessary.
7. Install coverplate over the pump shaft, tighten capscrews
(per torque chart).
8. Tighten packing gland to compress packing.
9. Install impeller, impeller gasket, impeller washer, lock washer
and capscrew, then tighten (per torque chart).
10. Install new volute gasket then install pump assembly into
volute. Tighten volute capscrews (per torque chart). Install
seal flushing tube. Install drain plug, close drain valve.
11. Open isolation valves, inspect pump for leaks, if not leaking
return pump to service. (See note for packing adjustment.)
NOTE:
Before starting pump, back off packing gland nuts or screws
until glands are loose. Re-tighten with fingers until glands are
just snug against the first packing ring. After pump is running
at first start, water may run freely from packing. This is normal
and should be allowed to continue for a period of time before
further tightening of the glands. Take up gland bolts uniformly,
one flat at a time.
An adequate leakage rate is not one single valve for all pumps
and installations, but is the amount required to provide ade-
quate cooling and lubrication. The required leakage will be
largely influenced by operating pressure, fluid temperature,
shaft speed, etc.
For fluid temperatures in the range of 32° to 190°F, average
leakage rates of 60 to 80 drops per minute are recommended.
However, each individual pump and installation will have
unique operating conditions that will result in broadly variable
leakage rate requirements.
At fluid operating temperatures near the upper limit of 190°F,
the maximum temperature rise of the leakage is particularly
important. A packed pump should never operate with steam
forming at the gland. This necessarily limits the temperature
rise to a maximum of about 20°F. If the formation of steam
persists at higher leakage rates, cooling water must be provided
by means of an external supply, or a heat exchanger used to
cool the by-pass flush.
WARNING: Unexpected Startup Hazard
Disconnect and lock out power before servicing.
Failure to follow these instructions could result in serious
personal injury or death, and property damage.
WARNING: Excessive System Hazard
Make certain the internal pressure is relieved before
continuing. Failure to follow these instructions could result
in serious personal injury or death, and property damage.
Caution: Extreme Temperature Hazard
Allow pump temperature to reach acceptable level
before proceeding. Open drain valve, do not proceed until
liquid stops coming out of drain valve. If liquid does not
stop flowing from drain valve isolation valves are not seal-
ing and should be repaired before proceeding. After liquid
stops flowing from drain valve, leave drain valve open and
continue. Remove the drain plug located on the bottom of
the pump volute. Do not reinstall plug or close drain valve
until reassembly is completed. Failure to follow these
instructions could result in moderate personal injury or
property damage.