also be sufficiently packed and rammed to prevent after settlement, and the material used shall be free from stones or rock fragments. The trenches shall, in all cases; be refilled with the material furnished by their excavation, provided that it be of a proper quality, and the necessary haul be not more than 500 feet. Earth borrowed or hauled over 500 feet, to refill the trenches (excepting trenches where rock has been excavated), will be paid for as embankment, at the price given under item of section seven. In streets and roads, the class of surface before existing, shall be replaced, so as to be in every way equal to that surface in materials and workmanship, and satisfactory to the water commissioner. Whenever trenches are excavated in or across streets paved with granite or wood blocks, or with asphalt, the contractor will be required to have the back-fill of trench thoroughly rammed (not less than three men ramming to each man filling the trench), and to replace the paving temporarily, so as to make the street passible for traffic; the permanent laying of the pavement in these cases, will be assumed by the city. A wooden box or vault shall be furnished and set over each of the stop cocks, air cocks, and fire hydrants, and the iron frames and covers shall be properly fastened to them. These boxes are to be made of the form and dimensions shown by samples furnished and approved by the water commissioner; they shall be made from sound, well seasoned oak lumber; the corner posts shall be of four-inch scantling, and the sides shall be formed from two-inch plank, set close, and securely nailed. M. L. H. 144. Specifications for Stop Valves. The following specifications for stop valves for water mains are thought to be particularly strong in the requirements governing the strength of the material used in the different parts. These requirements are followed up very carefully by numerous tests of the strength of the material, and in this way the character of the composition metal used has come to be very superior to that formerly employed, and much superior to that which would be obtained without such rigid specifications and tests. They are the standard specifications used in the St. Louis water depart ment. All the iron castings shall be made from a superior quality of iron, remelted in the cupola or air furnace, tough and of even grain, and shall possess a tensile strength of not less than 18,000 pounds per square inch. Test bars of the metal 3 inches by 1⁄2 inch when broken transversely, 18 inches between supports and loaded in the center shall have a breaking load of not less than 1,000 pounds, and shall have a total deflection of not less than 1% of an inch before breaking. Said bars to be cast as near as possible to the above dimensions without finishing, but correction will be made by the water commissioner for variations in thickness and width, and the corrected result must conform to above requirements. Specimen bars of the metal used, of a size and form suitable for testing, shall be prepared when required. These specimen bars shall be poured from the ladle at any time, either before or after the casting has been poured, as may be required, and shall present a true specimen of the iron used for making the castings. If any two test bars cast the same day do not show the required cross breaking load and deflection, all the castings made from the same mixture to be rejected. Each valve shall have the maker's initials, the numbers showing point in time of casting, and the year cast upon it. The year above and the number below, thus: 1890, 1990, etc. The figures and letters will be from 2 to 2 1⁄2 inches long, and shall have at least 6 inch relief. All the wrought iron used shall be of the first quality of American refined iron. All the composition metal used, except the valve stem, shall be composed of the following proportions, viz: 85 per cent. copper, 10 per cent. tin, and 5 per cent. spelter; and shall have a tensile strength of not less than 22,000 pounds per square inch, with 5 per cent. elongation in 8 diameters, and 5 per cent. reduction of area at breaking point. All castings must conform in shape and dimensions to the drawings. The castings must be clean and perfect, without blow or sand holes, or defects of any kind. No plugging or other stopping of holes will be allowed. The valve guides must be straight and smooth. Irregularities, if any, must be planed or chipped off smooth. All face joints must be planed true and smooth, in the most workmanlike manner, so as to make a perfectly water-tight joint, with a very thin layer of strictly pure lead cement. All bolt holes must be accurately drilled from templates. The upper part of valve to be finished to receive the valve stem, collar and stuffing box, and the fitting at this point must be such as to secure a perfect working joint. The valve to be a two-faced wedge valve; the castings for same to be as shown on drawing. The raised rims to be turned true with dovetailed channel to hold the composition rings. The faces must be brought to the exact angle before the rings are put on. The face rings are to be of composition metal, of quality hereinbefore specified, and are to be turned to fit the dovetail in the iron wedge. The composition rings of valves must be shrunk on, and also fastened by copper studs, placed not over three inches apart-the whole to be then brought to a true plane surface. The upper portion of the wedge to be arranged to receive the composition nut as shown. Care shall be taken to give the composition nut a perfect bearing surface-both top and bottom. On the 36 inch and 30 inch valves, the brass bearings of side guides shall be of the full dimensions, and have the exact clearance shown on drawings, and be secured in place by countersunk copper studs, placed not over three inches apart, after which the guides shall be brought to a true and smooth surface. The seats for rings in body of valve shall be turned true and smooth, and to the required angle as shown on drawings. The seat rings shall be of form and dimensions as shown on drawings, and faced true and smooth. Seat rings to be forced into position and thoroughly and securely fastened in place, and a perfectly water-tight joint secured. All valves of 10 inch diameter and upwards to be provided with indicator as shown on drawings. All wrought iron bolts and nuts to be made from the best quality of American refined iron. The nuts to be hexagonal and the heads square. Heads, nuts and threads to be standard size. Valve stem shall be made of phosphor bronze, quality B; or Crescent bronze, quality No. 2; or of first quality of "Stuckstede' bronze, and shall be free from flaws or defects of any kind, and have a tensile strength of not less than 30,000 pounds per square inch. Screw threads on the stems and nuts to be cut in most perfect manner, and of the exact pitch shown on the drawings, and so as to work true and smooth, and in perfect line throughout entire lift of valve. There shall be two dowel pins, made of composition, set in the flanges connecting the dome and main casting, as shown on drawings, for the purpose of centering and bringing into perfect alignment these castings. Holes for dowel pins to be drilled and reamed tapering, and pins turned to perfect fit. Pins for the 36 inch and 30 inch to be 1 inch in diameter; for the 20 and 15 inch, 3/4 inch diameter; for the 12 and 10 inch, 8 inch diameter; and for the 8 and 6 inch, 1⁄2 inch diameter. Gearing to be extra strong, and of the form and dimensions shown. Pinion post to be of a good quality of steel; key seats shall be truly cut, and keys made of steel, and of the full dimensions. Cap nuts for valve wrench to be of the following outside dimensions: for all 6 to 15 inch valves (inclusive), to be 2 inches square; for the 20 inch, to be 234 inches square; and for the 30 and 36 inch, to be 34 inches square. All iron work, after being thoroughly cleaned, to be painted with three good coats of paraffine varnish, applied hot. The valves shall be tested by hydraulic pressure, as follows: First. Heads shall be secured at each end of casting, the valve opened, and a pressure of 200 pounds per square inch applied. Second. Each face joint of valve shall be tested by closing the valve, leaving one end of the casting open, and applying a pressure of 100 pounds per square inch to the other this operation to be reversed to test the other face. Any and all defects developed in testing shall be thoroughly corrected to the satisfaction of the water commissioner. After testing all valves to be thoroughly drained. All parts of valves of the same size to be perfectly interchangeable. The water commissioner may take at random any wrought iron bolt or nut, and have it broken in a testing machine. If bolt shall not fulfill the requirements of table below, the whole lot of that size and make to be rejected: The Water Commissioner may take at random any valve stem with nut, either finished or unfinished, for 6, 8, 10 or 12 inch valves, and have it broken in a testing machine. If any stem or nut shall not fulfill the requirements of the table below, the whole lot of that make and size to be rejected. All valve stems for 15 inch and larger valves to be cast with a coupon on one end, 15 inches long by 11⁄2 inches diameter. Any one or all of these coupons may be taken by the Water Commissioner and broken in a testing machine. If any coupon shall show a breaking strength of less than 30,000 lbs. per square inch, or shall have a ductility of less than 8 per cent. in 8 diameters, the stem from which it was cut shall be rejected. For all materials taken by the Water Commissioner for testing which are found to conform to the above requrements, there shall be added to the final estimate: For all wrought iron.... For all Stuckstede bronze... 7 cents per pound. .25 cents per pound. .25 cents per pound. 25 cents per pound. The broken material to belong to the party of the second part. For all materials taken for testing which do not come up to requirements there shall be no allowance, and the broken material shall be returned to party of the first part.* The whole to be put together in a thorough and workmanlike manner, and delivered, packed, ready for use. The working parts to be perfectly fitted together and working true in line. The joint between the face rings, when the valve is closed, must be absolutely water-tight. The whole to be in material, workmanship and finish, to the satisfaction and acceptance of the water commissioner. M. L. H. LUMBER GRADING AND CLASSIFICATION. 145. Rules of the Southern Lumber Manufacturers' Association. The rules given in the following articles were adopted by the Southern Lumber Manufacturers' Association at Memphis, Tennessee, February 21, 1895. They are given here entire to assist the engineer to use descriptive terms in the same sense in which they are used by the lumber manufacturers and dealers. While they are intended to apply only to southern yellow pine, they can be understood to apply in a general way to all merchantable lumber. Since lumber is always sold under certain grade names, and since in the large In the St. Louis specifications the contractor is the party of the first part. |