PACKING PISTON AND VALVE RODS.
When the piston or valve rod of an engine or pump needs re-packing, take off the stuffing box gland, remove all the old packing carefully, and replace with new.
If a patent packing is used, it should be cut in suitable lengths diagonally across the packing, making the angle of one end opposite from that of the other, so that when ends are brought together they will make a splice joint. The joint of each ring of this packing should be placed at opposite sides of the rod, and the stuffing box filled, the gland replaced and screwed up just tight enough to stop leakage. If hemp packing is used, take about the amount required and pick it to pieces, removing all sticks, lumps or hard substances. Then twist it into three compact cords, saturate well with oil or tallow, and braid the cords together tightly. Then wind this braid around the rod until stuffing box is full, replace the stuffing box gland, and screw up as before described.
Care should be taken not to screw the packing in stuffing boxes too tight, as it not only increases the friction on the rod and diminishes the power of the engine, but will have a tendency to flute the rod. If the rod is once fluted, it will be very difficult to stop leakage at this joint.
When stuffing box of water piston of pumps needs re-packing, the same rule will apply, with the exception that little or no grease or tallow should be used upon the packing.
Always keep piston and valve rod packing in a clean place, as any dirt or gritty substance that may become attached to it will have a tendency to cut the rod.