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Steel Pipes Tests,
Cast Iron Pipes and Specials.
Ball and Socket Joints.
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16. The pipes to be made from plates bent in bending rolls and welded by the water gas process, the heat being applied locally inside and out and the welding load by a roller under hydraulic pressure on a cantilever anvil.
All pipes to be smooth inside and outside and free from scale, blisters and other
defects.
The following tolerances not to be exceeded-
24% under or 71% over the specified weight.
1" over or under the specified diameter save at the joints which must be
made accurately to gauges and templates and interchangeable.
The pipes to be supplied in average effective lengths of 25 feet, as follows- Suitable for putting together at the site in Hong Kong in stretches of 200 feet' the intermediate joints being of the welded flange type shown on drawing No. 6' faced and drilled for countersunk rivets, and the terminal joints being of the welded on flange type to British Standard Specification No. 10 Table II for a pressure of 225 lbs. and between each 200 feet stretch a ball and socket joint, of cast steel, or cast iron if approved by the Engineer. Suitable bolts and rivets to be supplied for jointing the above into two continuous 18" pipe lines each having a total length of 5,650 feet including ball and socket joints.
Each pipe to be subjected at Works to a pressure of 1,000 lbs. per square inch between the heads of a hydraulic testing machine, to be thoroughly cleaned and free from all rust, mill scale and foreign matter adhering to the surface, and each length of pipe to be subjected to a centrifugal process whereby the interior surface of each pipe is coated with a special bituminous solution to an approximate uniform thickness of ", giving a smooth glassy surface, impervious to water, acids, alkalies or corrosive action, such solution being applied in accordance with Patent No. 224365 or other approved method, to ensure that this internal coating will withstand damage, heat or handling in transit to the tropics. The exterior surface of the pipe to be then coated with a special bituminous solution applied cold, and wrapped with Hessian Cloth weighing not less than 7 ozs. per square yard, saturated with a similar solution and wound spirally round the pipe with an overlap of not less than 1". This wrapping to be repeated a second time so as to ensure a minimum thickness of two ply of wrapping on the outside, the wrapping being stopped off 3′′ short of the flange joints, the intermediate joints being subsequently coated and wrapped with solution and Hessian prior to launching each 200 feet stretch of pipe.
From time to time during the manufacture of the pipes the Inspector may require short pieces to be cut from the pipes for examination of the weld. Each pipe must be tested in the Inspector's presence under hydraulic pressure. The pressure is to be clearly and satisfactorily indicated by a proof testing gauge to the satisfaction of the Inspector. The pipes are to be hammered throughout their length when under pressure and any pipe which leaks or in any way fails under this test will be rejected.
Each pipe shall have hay bands wound on spirally at 8 inches pitch and secured with wire 14 W.G. wound spirally in the opposite direction or such other protection as to ensure safe arrival in the Colony, as the Inspector may approve or require.
17. Cast iron pipes, bends and junctions, where required, shall be in strict accordance with B.S. Specifications Nos. 78-1917, and 10-1904, and to be constructed to the dimensions set out therein for a pressure of Boo feet.
18. The ball and socket joints, Drawing No. 6, of Glenfield & Kennedy's or other approved design, to have a working diameter of about 30" and to be of cast steel made by the Siemens Martin or other approved process, having a tensile strength of 26 to 35 tons per square inch of section.
Tensile tests of the material to show an elongation of 15% to 20% on British Standard Test Pieces.
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The material to show the following analysis —
Carbon
Manganese not to exceed
Silicon
Sulphur not to exceed
Phosphorus not to exceed
*15
to .2%
I%
*25% to 3%
*06%
*06%
The castings to have a smooth surface and to be free from cracks, blow holes and other defects, and to be thoroughly annealed and dipped in an approved bituminous solution before machining or galvanized or otherwise protected. Care must be taken that each joint is efficiently protected.
The working surfaces (ball and socket) to be turned smooth and spherical, the glands and stuffing boxes being accurately machined to a working fit and all flanged faced and drilled to template, so as to be interchangeable with one another and with the flanges of the pipes.
Ali bolts connecting ball and socket and pipe flanges to be of mild steel and galvanized after threading, 5% spares being provided.
Each ball and socket joint to be packed with white metal of approved quality and provided with two soft sheet lead joints 3" thick covering the whole face of the outer flanges.
Each ball and socket joint after machining to be fitted with temporary packing and subjected to the hydraulic test pressure of 500 lbs. between the heads of a hydraulic testing machine.
Pipes and fittings to be coated with white lead on all machined surfaces and protected by wooden discs with temporary bolts against damage when in transit.
The whole of the process of manufacture, testing and protecting with bituminous compound, is subject to the approval of the Inspector.
19. All structural steel work to be in accordance with British Standard Structural Steel Specifications Nos. 15-1912, and 1-1920, and wherever possible to be heavily Work. galvanized, and where not galvanized to be properly cleaned and painted before shipment, and after erection scraped and cleaned and coated with selected bituminous paint in two coats of approved colour.
20. All screw valves, air cocks and other accessories to be manufactured by Valves. Glenfield & Kennedy or other approved firm, of the best quality, gun-metal faced and fitted, with bronze spindles, cast iron pedestals with 18" hand wheels, brass indicators and index scales, selected patterns, and where necessary fitted with by- pass valves and connections.
All valves, not shown fitted with pedestal opening gear, to be furnished with keys so as to be conveniently operated from valve house floor. All valves and other cast iron work to be coated with bituminous covering.
PIPE LINES.
21. The pipe lines between the Kowloon and Victoria sides of Hong Kong Pipe Lines. Harbour to begin behind the sea wall on the Kowloon side by a 24′′ pipe let through the wall and projected sufficient distance from the back of the wall to allow for a flanged joint being properly made with a proposed new 24" main to this point. The 24" pipe to be continued over the Harbour to a valve chamber situated about 40 feet from the face of the sea wall. In the valve chamber the 24" pipe to divide into two 18" pipes, each of which is to descend vertically to the level shown on the section and to be furnished with all the operating valves, sand catchers, and discharge pipes, as shown on the Drawing No. 7.
The crossing of the Harbour to be in line and to the levels and dimensions shown on Drawings Nos. 3 and 6.
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