_b._ This plate must have an area of not less than one square foot, and must be made of an alloy at least two-thirds aluminum and the remainder zinc. The letters must be at least one-half inch in height, plain and distinct, with their surfaces raised on a black background and buffed off to a dead smooth finish.
The name of pump manufacturer may also be placed on this plate, if desired.
_c._ A smaller plate of composition must be attached to steam chest bearing the size of pump, the shop number, and the name of shop in which the pump was built.
_a._ The maker must warrant each pump built under these specifications to be at time of delivery, in all its parts, strong enough to admit of closing all valves on water outlet pipes while steam valve is wide open and steam pressure eighty pounds, and agree to so test it before shipment from his works.
_b._ The pump must be warranted so designed and with such arrangement of thickness of metal that it shall be safe to instantly turn a full head of steam on to a cold pump without cracking or breaking the same by unequal expansion.
A systematic shop inspection must be given to each pump to ensure completed workmanship, and to prevent the use of defective parts, improper materials, or the careless leaving of foreign matter in any part of the cylinders or chests.
Several instances have occurred in which chisels, bolts, or core irons have been found in steam chests or steam cylinders. This has resulted in a serious crippling of the pump and in some cases requiring repairs to be made before the pump could be used for fire purposes.
_a._ These must be of hard close iron with metal so distributed as to ensure sound castings and freedom of shrink cracks. The following are the minimum thicknesses acceptable:
14″ Diam. 7/8″ thick 16″ „ 15/16″ „ 18″ „ 1″ „ 20″ „ 1-1/8″ „
_b._ The inside face of the steam cylinder heads and the two faces of the piston must be smooth surfaces, fair and true so that if the piston should hit the heads it will strike uniformly all around, thus reducing to a minimum the chances of cramping the piston rod or injuring the pump.
_c._ All flanged joints for steam must be fair and true and must be steam tight under 80 lbs. pressure if only a packing of oiled paper 1/100 inch thick covered with graphite were used. Jenkins, “Rainbow” or equivalent packing of not exceeding 1/32 inch original thickness is acceptable. Oiled paper is not acceptable as a final packing, as it burns out.