Specifications for triple-expansion twin-screw propelling engines, with boilers & auxiliary machinery for a protected cruiser of about 5,500 tons cruising displacement

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1890. Excerpt: ... drainage system of the jacket of each cylinder will be entirely independent as far as the trap-discharge, from which point the drains may be in common. All pipes in the jacket-drain system will have union joints so as to be easily overhauled. 11. VALVE-CHESTS. The valve-chest of each high-pressure cylinder will be fitted for one piston-valve, each intermediate-pressure for two, and each low-pressure for four. There will be openings at each end for inserting and removing the valves and working linings. The chests will be accurately bored and faced for the reception of the working linings. Before the insertion of the linings the steam and exhaust passages must be thoroughly cleaned out and pickled, and care taken that the passages are nowhere contracted to less than the specified areas. Each intermediate-pressure and each low-pressure valve-chest will have a 3-inch adjustable-spring safetyvalve of approved pattern. They will be loaded to 80 and 25 pounds, respectively, for the intermediate and low-pressure chests. All valve-chests will also be fitted with approved composition drain-cocks or valves that may be operated from the working-platform, the valves to discharge through pipes into the bilge and feed-tanks, with the necessary valves for directing the water to either. 12. VALVE-CHEST LININGS. There will be a working lining at each end of each valve-chest for each piston-valve. They will be of closegrained cast-iron as hard as can be properly worked, accurately turned and faced to fit the casings, and accurately bored to an internal diameter of i8 inches in the high-pressure, and 23 inches in the intermediate-pressure, and 2i inches in the low-pressure, leaving the walls i inch thick. They will be forced into place, making all joints perfectly tight, and...