TM 5-4210-233-14&P-2
6-6. FIRE PUMP - Continued
(20) Operate the pump at 75 to 150 psi (517 to 1034 kPa) discharge pressure for five minutes and
observe leakage. Acceptable leakage for flexible graphite packing is 10 to 15 drops/minute. A
leakage of 1 drop/minute is acceptable after complete break-in.
(21) Shut down pump and feel packing glands. Allow packing glands to cool or wait five minutes to
restart pump (whichever is longer) if leakage rate is too low or packing glands are hot.
(22) Repeat steps (20) and (21) (a maximum of three times) until packing glands are cool (to warm) and
water leaks from the stuffing box. Tighten packing gland adjustment nuts one flat if leakage in step
(20) was too high and the glands were not hot.
(23) Operate the pump (at 75 to 150 psi (517 to 1034 kPa) discharge pressure) for two minutes and
observe leakage.
(24) Shut pump down and feel packing glands. Go to step (27) if leakage is high and packing glands
are cool to warm. Allow packing glands to cool or wait five minutes (whichever is longer) if leakage
is low or packing glands are hot.
(25) Operate the pump (at 75 to 150 psi (517 to 1034 kPa) discharge pressure) for two minutes and
observe leakage.
(26) Shut pump down and feel packing glands. Go to step (27) if leakage is high and packing glands
are cool to warm. Loosen adjusting nuts 1/2 flat if leakage is too low or packing glands are too hot.
Then repeat steps (23) to (25) as required.
NOTE
Synthetic packing will melt and seal the shaft if the packing gland nuts are too
tight. The melting is usually confined to the packing ring nearest the packing
gland. Replacement of the packing ring nearest the packing gland will correct
this situation.
(27) Tighten packing gland adjustment nuts one flat. Operate pump (at 75 to 150 psi (517 to 1034 kPa)
discharge pressure) for two minutes and observe leakage. Repeat steps (24) to (26) as required.
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