Standard Specifications for Hydrants and Valves*
General News Articles
Hydrants.—Classification: 1. The size of hydrants shall be designated by the nominal diameter of the valve opening, which must be at least 4 inches for hydrants having two 2 1/2-inch hose nozzles; 5 inches for hydrants having three 2 1/2inch hose nozzles, and 6 inches for Hydrants having four 2 1/2-inch hose nozzles, and shall be classed as one-way, two-way, three-way or fourway, etc., according to the number of 2 1/2-inch hose outlets for which they are designed.
Area Water Way: 2. The net area of the hydrant at the smallest part, when the valve is wide open, must not be a less area than 20 per cent, in excess of the size of the valve opening.
Bell Ends or Flange Ends: 3. All hydrants must be fitted with bell ends to fit standard castiron pipe, or, if flanged, they must be fitted with flanges of the standard dimensions corresponding to the pressure under which they are to be used; connecting pipe or branch from main in no case to be less in diameter than the valve opening.
General Design.—Change in Diameter: 1. Any change in diameter of the water passage through the hydrant must have easy curves, and all outlets must have rounded corners of good radius.
Water Hammer: 2. Hydrants must be so designed, particularly as regards the pitch of the thread of the operating stem, that, when properly operated, water hammer will not be caused which will give an increased pressure to exceed the working pressure when such pressure is over 60 pounds, nor increase the pressure more than 60 pounds when operated under less working pressure than 60 pounds.
Strapping: 3. Hydrants must be so designed that the leaded joint under the ground can be strapped.
Material.—Cast Iron: All castings shall be made from a superior quality of iron, remelted in cupola or air furnace, tough and of even grain, and shall possess a tensile strength of 22,000 pounds per square inch. The casting must be clean and perfect, without blow or sand holes or defects of any kind. No plugging or stopping of holes will be allowed.
Specimen Bars: Specimen bars of the metal used, each being 26 inches long by 2 inches wide and 1 inch thick, shall be made without charge as often as the engineer may direct, and in default of definite instructions, the contractor shall make and test at least one bar from each heat or run of metal. The bars when placed flatwise upon supports 24 inches apart, and loaded in the center, shall support a load of 2,200 pounds, and show a deflection of not less than .35 of an inch before breaking; or if preferred, tensile bars shall be made which will show a breaking point of not less than 22,000 pounds per square inch. Bars must be cast as nearly as possible to the dimensions without finishing, but corrections may be made by the engineer for variations in width and thickness, and the corrected result must conform to above requirements.
Wrought Iron : All wrought iron used shall be of the best quality of refined iron, of a tensile strength of at least 45,000 pounds per square inch.
Composition Metals: All composition or other non-corrodible metals used to be of the best quality, to have a tensile strength of not less than 32,000 pounds per square inch, with 5 per cent, reduction of area at breaking point.
Hose Nipples and Valves.—Hose Nipples: 1. Hose nipples must be of bronze or suitable noncorrosible metal, either threaded with a fine thread into the hydrants and securely pinned in place or carefully locked and caulked in place.
Hose Threads: 2. Hose threads on all hydrants to be installed in any given community must of necessity be interchangeable with those already in service, but, where practicable, threads should conform to the national standard.
Hydrant Seat and Gate.—Seat: 1. The seat must be made of bronze or suitable incorrodible metal, securely fastened in place.
Valve: 2. The valve must be faced with a suitable material and must be designed so that it can be easily removed for repairs without digging up the hydrant.
Drip Valve.—Drip: A positively operating non-corrodible valve must be provided and arranged so as to properly drain the hydrant when the main valve is closed. The seat of the waste valve, which must be fastened in the hydrant securely, must be made of non-corrodible material. All other parts of the drip mechanism must be SO designed as to be easily removed without digging up the Hydrant.
Operating Parts.—Threads: 1. The operating threads of the hydrant must be so arranged as to do away with the working of any iron or steel parts against iron or steel. Either the operating screw or the operating nut must be made of noncorrodible metal, and sufficiently strong to perform the work for which they are intended.
Top Nut: 2. The stem must terminate at the top in a nut of pentagonal shape, finished with slight taper to 1 1/2 inches from point to flat, except for hydrants to be installed where existing hydrants have different shape or size of nut, in which case the additional hydrant must have operating nut similar to the old ones for uniformity.
Stuffing Box and Gland.—Stuffing Box : 1. The stuffing box and gland must be of bronze or suitable non-corrodible metal or bushed with bronze or suitable non-corrodible metal, when an iron or steel stem is used or when an iron operating stem nut passes through the stuffing box. When packing nut is used, it must be made of bronze or suitable non-corrodible metal. The bottom of the box and end of the gland or packing nut must be slightly beveled.
Gland Bolts: 2. Gland bolts or studs must be at least 1/2 of an inch in diameter.
Material: 3. Gland bolts or studs may be cither of bronze or suitable non-corrodible metal, iron or steel. The nuts must always be of bronze or suitable non-corrodible metal.
Hydrant Top.—Top: 1. The hydrant top must be designed so as to make the hydrant as weatherproof as possible and thus overcome the danger from water getting in and freezing around the stem. Provision must be made for oiling, both for lubrication and to prevent corrosion. A reasonably tight fit should be made around stems.
2. There must be cast on top of the hydrant, in characters raised 1/8 of an inch, an arrow at least 2 1/2 inches long and the word “Open” in letters 1/2 of an inch high and 1/8 of an inch in relief, indicating direction to turn to open the hydrant.
Hose Caps.—1. Hose caps must be provided for all outlets, and must be securely chained to the barrel with a chain constructed of material not less than 1/8 of an inch in diameter.
Cap Nut: 2. The hose cap nut must be of the same size and shape as the top or operating nut.
Washer in Cap: 3. When requested by the purchaser a leather, rubber or lead washer must be provided in the hose cap, set in a groove to prevent its falling out when the cap is removed.
Markings : The hydrant must be marked with the name or particular mark of the manufacturer.
Testing: Hydrants for pressure of 150 pounds or less, after being assembled, shall be tested by hydraulic pressure to 300 pounds per square inch before leaving the factory. If the working pressure is over 150 pounds per square inch, the hydrants must be tested to twice the working pressure. The test must be made with valve open in order to test the whole barrel for porosity and strength of hydrant body. A second test must be made with valve shut, in order to test the strength and tightness of the valve.
Opening: Hydrants must open to the left (counter clockwise) except those to be installed where existing hydrants open to the right, in which case the additional hydrants must turn the same as the old ones for the sake of uniformity.
Your committee has not included specifications for hydrants with independent cutoffs, not deeming these hydrants “standard.”
Your committee recommends the use of the smaller standard sizes of hydrants at frequent intervals, rather than large hydrants with numerous outlets spaced at longer intervals.
Specifications for Valves
Castings: All iron castings shall be made from a superior quality of iron, remelted in cupola or air furnace, tough and of even grain, and shall possess a tensile strength of 22,000 pounds per square inch. The castings must be clean and perfect. without blow or sand holes or defects of any kind. No plugging or stopping of holes will be allowed. Test Bars: Specimen bars of the metal used, each being 26 inches long by 2 inches wide and 1 inch thick, shall be made without charge as often as the engineer may direct, and in default of definite instructions the contractor shall make and test at least one bar from each heat or run of metal. The bars when placed flatwise upon supports 24 inches apart, and loaded in the center, shall support a load of 2,200 pounds and show a deflection of not less than .35 of an inch before breaking; or if preferred, tensile bars shall be made which will show a breaking point of not less than 22,000 pounds per square inch. Bars to be cast as nearly as possible to the dimensions without finishing, but corrections may be made by the engineer for variations in width and thickness, and the corrected result must conform to above requirement.
Xame: Each valve shall have the makers’ name cast upon if. Wrought Iron: All wrought iron used shall be of the best quality of refined iron, of a tensile strength of at least 45,000 pounds per square inch. Composition Metals: All composition metals to be of the best quality, and, except the stems, to have a tensile strength of not less than 30,000 pounds per square inch, with 5 per cent, elongation in eight diameters, and 5 per cent, reduction of area at breaking point. Face Joints: All joints shall be faced true and smooth, so as to make, with suitable gaskets, a perfectly watertight joint.
Fittings : The fitting of all parts must be such as make perfect joints, and all parts of the valves of the same make and the same size shall be interchangeable. Valves to open as specified by the engineer.
Bolts and Nuts: All bolts and nuts in valves to be made from the best quality of double refined wrought iron or steel, heads, nuts and threads to be standard sizes.
Kind of Valves: Valves shall be fully mounted with bronze or suitable non-corrodible metal, and be either of the double disc or made up gate type with bronze or suitable non-corrodible metalmounted wedging devices or have wedge-shaped gates with double faces and seats, designed to work equally well with pressure on either side of the gate. The gates (or discs) shall be of cast iron with bronze or suitable non-corrodible metal faces These faces shall be machined, dovetailed and driven into corresponding machined grooves in gates (or discs) or riveted on with bronze or suitable non-corrodible metal rivets. The seats for composition rings in body of valve shall be turned and threaded before rings are screwed in.
Seat and Gate Rings : Both seat rings and gate (or disc) rings shall have smooth and true faces, and make a perfectly watertight joint.
Valves shall have hub ends suitable for laying with classes B and C American Water Works Assoc:ation standard pipe. All valves 24 inches in diameter and larger shall be geared.
Bypasses: Where bypasses are required, they shall, unless otherwise specified, be of the following sizes:
Weight: Valves without bypasses shall be approximately not less than the following weights for the respective sizes:
Valve Stems: Valve stems shall be made of solid brass or suitable non-corrodible metal, free from defects, and shall have a tensile strength of not less than 45,000 pounds per square inch.
Threads: I breads on stems to be square, acme or one-half V, and cut in most perfect manner, so as to work true and smooth and in perfect line throughout the life of the valve.
Size of Stems: Valve stems at the bottom or base of the thread shall not be less than the following sizes in diameter:
Wrench Nut: The wrench nut on stem shall be 2 inches square, with arrow cast on showing direction which valve is to turn open.
Painting: All iron work, after being thoroughly cleaned, to be painted throughout with asphaltum varnish, or suitaole paint, or dipped in suitable coating material.
Testing: Valves must be tested for leakage and distortion as follows: On double disc or made-up gate type, the body of the valve shall be drilled and tapped with a hole for pipe and a removable ping inserted, through this hole a hydraulic pressure of 300 pounds per square inch shall be applied; the wedge-shaped gate type by an hydraulic pressure of 300 pounds per square inch applied, first, between one end and the gate; second, between the opposite end of the gate, and third, in the bonnet with gate open.