6-6. FIRE PUMP - Continued
(3) Flexible Graphite (Grafoil) packing: Packing should not require complete replacement. A Flexible
Graphite (Grafoil) ring should be added when the gland cannot go further into the stuffing box.
(Flexible Graphite (Grafoil) is 100% lubricant, therefore it is effective as long as force can be applied
to deform it toward the shaft.)
(4) Pressurized Water Source: Another fire truck or hydrant may be required to supply pressurized water
to blow out packing if the fire truck does not have an internal tank large enough to allow continuous
recirculation. The relief valve system should be set at 80 psig (and operating) on the fire truck
supplying pressurized water.
(5) A compressed air supply and air hose nozzle is useful in cleaning out stuffing box water supply
Immobilize Fire Truck: Park on level ground. The fire truck wheels should be
blocked and the parking brake set (if located at the rear wheels, not between
truck and pump transmission.)
(6) Park truck on level ground with adequate provision for draining water from pump.
Stuffing Box Leakage: Leakage from a stuffing box can be quite hot even after the
pump has been shut down. Wear safety glasses and other protective clothing.
(7) Blow the packing out with pressurized water provided by running the fire pump or pressurized water
provided by an external source such as another fire truck or hydrant.
Remove packing from one stuffing box at a time. (Replace packing in one
stuffing box before blowing out packing in other stuffing box.)