Q. How do you repack a stuffing-box?
A. If any of the old packing is used, it should be put in after the new. See that the stuffing-boxes are well cleaned and oiled.
Put on the piston-rod one ring of 1-inch Garlock's "waterproof hydraulic" packing, and force it well to the bottom of the stuffing-box by a wooden stick and mallet. Treat each layer of packing in a similar manner, being careful to break joints until five rings of new packing have been inserted, or an equal amount of new and old when any of the latter is used. Place the gland on the follower, enter them together in the box and screw up the follower.
No more force should be used on the spanner-wrench than that of two men, and generally that of one man is sufficient. The addition of the pipe to the end of the spanner-wrench should not be permitted.
Q. How do you remove old packing from recoil-cylinders?
A. Remove the gland and follower (using new extractor, to be furnished by the Ordnance Department). Close the extractor around the piston-rod and insert the locking-pin. Turn the extractor to the left, with pressure on the packing, until the needles are firmly engaged in the packing. Draw the packing out, turning slowly to the left. In the case of a box with interior thread, and if the ring is tight, it should be unscrewed and not stripped out by the thread, because unless unscrewed it would catch upon and be injured by the thread.
Extractor-bars are provided to be used for starting the packing from its seat, and by inserting the toes of the bar in the rack-teeth and prying over the edge of the box, being careful not to injure the thread.
Q. What is the object of the throttling-valve?