Mild-Steel Riveted Pipes or Tubes.-Particulars and weights are given in the three following Tables of some riveted pipes of mild-steel made by the Steel-Pipe Company. The weight, thickness, and working head of the pipes are calculated by the following formulæ : weight in lbs. per lineal foot. d = diameter in inches. w weight of plate in pounds per square foot. = = thickness of pipe in inches. H = working head in feet of water. The weight of steel pipes per lineal foot, W = dx w x 33. Cast-iron Pipes { H= '00012 d The thickness of pipes and working head of pressure are, t=00012 dH t *000025 d Table 165.-RELATIVE THICKNESS OF RIVETED PIPES OR TUBES FOR EQUAL STRENGTH. Table 166.-RELATIVE WEIGHT OF PIPES OR TUBES FOR EQUAL STRENGTH. The longitudinal seams of the pipes are double riveted, and are estimated to have 70 per cent. of the strength of the solid undrilled plates. The pipes are united in lengths of from 4 to 6 feet with circular seams of single-riveting. Table 165 shows that the resistance to bursting of riveted steel-pipes of the given strength may be 5.6 times that of cast-iron pipes of equal thickness. Table 167.-WEIGHT OF ONE FOOT IN LENGTH OF RIVETED STEEL-PIPES OR TUBES, WITH PLAIN ENDS. Table 168 continued.-BREAKING-STRENGTH OF MATERIALS. NOTE. The strength of steel is diminished to the extent of from 25 to 50 per cent. by annealing, and its strength is increased from 15 to 60 per cent. by hardening in oil. Specific Gravity.-The specific gravity of a body, is its weight in proportion to an equal bulk of pure water, and the standard of comparison for olids and liquids is a cubic foot of pure water at 62° F., which weighs 1,000 ounces avoirdupois. |