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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 formulae:— Let W = weight in lbs. per lineal foot. d = diameter in inches. w = weight of plate in pounds per square foot. f = thickness of pipe in inches. H = working head in feet of water. The weight of steel pipes per lineal foot, W = d x w x 33. The thickness of pipes and working head of pressure are,
Table 165-RELATIVE THIcKNFss of RiveTED PIPEs or TUBEs for EQUAL STRENGth.
Description. Cast-Iron. Wrought-Iron. Steel.
Weight of 1 square foot, 1 inch thick | 37.5 lbs. | 40 lbs. 40.8 lbs. Tenacity per square inch 18Ooo lbs. 486Colbs. | 72000 lbs. Relative strength for equal thicknesses I 2:7 4 Factor of safety IO 6 5 Relative strength due to factor of
safety I 4'5 8 Reduction in strength due to riveted
joints -- 30 per cent. 30 per cent. Relative strength after reduction for
riveted joints I 3' 15 5-6 Relative thickness for plates of equal
strength I "3174 1786
Table 166.-RELATive Wright of PIPEs or TUBEs for EQUAL STRENGTH.
Description. Cast-Iron. Wrought-Iron. Steel. Thickness of plates, weighing 40 lbs. per square foot 1'o66 inches. 1 inch, 9804 inch, Relative strength for equal weight I 2'533 3:678 ! Relative strength due to factor of safety I 4'22 7.356 Relative strength after reduction for riveted joints I 2'955 5' 149 Relative weight of plain cylinders of equal strength I 3384 1942 Increase in weight of pipes due to socket and spigot joints 5.8 per cent.15 per cent. 15 percent. Relative weight of pipes of equal strength l 3678 "2 I I I
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 Foor IN LENGTH of RiveTED STEEL-PIPEs or TUBEs, with PLAIN ENDs.
Table 168.-BREAKING-STRENGTH of MATERIALs IN Toss PER SQUARE
INCh. Breaking Breaking Strain in Strain in Description of Materials. Tension per Compression Square Inch, per Square in Tons. Inch, in Tons. Cast-steel bars, rolled and forged . 52 Shear-steel bars ditto 5o | Bessemer-steel bars ditto 48 Blistered-steel bars ditto 45 Spring-steel bars ditto 32 Steel boiler plates ditto 32 IS Lowmoor or best Yorkshire bar iron 26 I 2 Ordinary good merchant bar-iron 25 I 2 Hoop-iron, best quality, average . - - . 25 Lowmoor or best Yorkshire iron plates along the fibre | 24 ditto ditto ditto across the fibre | 2: Ordinary good angle and tee-iron . - . 22 Ordinary good boiler-plates along the fibre 2 I ditto ditto across the fibre IS Ordinary good ship-plates along the fibre . 2O ditto ditto across the fibre 17 Cast-iron, best quality . - 7 48 ditto ordinary average quality 6 42 Malleable cast-iron, best quality 2O Phosphor-bronze wire, not annealed 55 s Steel wire, not annealed, best quality 53 Brass wire ditto , best quality 36 Iron wire, best quality . ŽS Copper wire. - - - 28 Homogeneous metal bars, best - . . . 4C Muntz metal . - - . 3 copper; 2 zinc 22 Sterro metal. - - - - - - 27 Brass tubes . - - . 70 copper; 3o zinc | 1.3% Railway rails, iron flange . - - - - - 2O ditto iron double-headed . 24 ditto steel flange . - 34 ditto ditto double headed 44 Railway-wheel steel tires . 42 Aluminium-bronze 32 58 Phosphor-bronze 25 Palladium wire . 23 Nickel . - 2O Cobalt - - 18 Copper, wrought 15 Copper, cast. - - 9 Gun-metal and bronze : - - - I4 6 Brass 8 4"> Soft solder 3'2 Zinc, cast . - - - - 3’t
Table 168 continued.—BREAKING-STRENGTH of MATERIALs.
Tin, cast . - - - - - - - 2
ditto I to 3 ditto - - - - 3
ditto 3 to 5 ditto 2°4
ditto 5 to 7 ditto 2: 18
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
t,000 ounces avoirdupois.