steam gage (stem gaj)

An attachment to a boiler to indicate the pre ure of steam; a pre ure-gage. There are many forms. One of the older is a bent tube partially filled with mercury, one end of which connects with the boiler, so that the steam raises 20 80 14 e. 8 -C 6 a , high-pre ure cylinder; b , low-pre ure cylinder; c, induction and eduction-valve for a in position of exhaust from lower end and of induction to upper end of cylinder; d, pa age for steam from a to b; e, induction and eduction-valve for b ; f , f, balance-plates for valves of a and b , g , g ' , pistons; h, h ' , piston-rods; 1, 1, cro -heads; 2, slipper-guides for cro -heads; 4,, connecting-rods; 1, 1 , cranks; m , crankshaft; w, shaft which drives feed-pump o and also bilge-pump (not shown) on the opposite side;, worm on main shaft gearing into worm-wheel qon the shaft n , and actuating pump-plungers by crank and pitman connection; ", r, eccentrics; s, s ', eccentric-rods; t, t', links connected by link-blocks with valve-stems u, u'; v, crank-lever which turns a segmental worm-gear, keyed to the rock-shaft w carrying the rocker arms x , x ' , for reversing high-pre ure and low-pre ure valves respectively; y, bedplate;, columns supporting the cylinders; s ' , tie-rods for stiffening the columns; a ' , exhaust from low-pre ure cylinder to the condenser (not shown); a ", butterfly throttle-valve; b ' , gear for operating throttle-valve; c ' , relief-valves. is also used as a pumping-engine for supplying water to cities. Steam-pre ure is not used to raise the water, but to lift a long loaded pump-rod, whose weight in its descent is the power employed to force up the water. The motion is regulated by a kind of hydraulic regulator invented by Smeaton, and called a cataract. - Direct-acting steam-engine, a steam-engine in which the power of the piston is transmitted to the crank without the intervention of levers, side-beams, or a working-beam. - Disk steam-engine, a form of rotary engine in which the steam-pistons act succe ively against a revolving disk set at an angle to the plane of rotation, thus imparting a gyratory motion to a central shaft upon which the disk is mounted, the end of this shaft being connected with a crank turning in the plane of rotation. - Double-acting steam-engine, the ordinary form of steam-engine, in which the steam acts upon both sides of the piston.- Double-cylinder steam-engine, a steam-engine hav- ing two steam-cylinders acting in combination with each other. See compound steam - engine . - Double expansion steam-engine. (a) A double-cylinder steam-engine in which steam is used expansively. (b) A compound steam- engine.-Double steam-engine, a steam-engine having two cylinders in which the pistons make either simulta- neo us or alternate strokes and are connected with the same crank-shaft. - Duplex steam-engine. Same as double steam-engine. High-pre ure steam-engine. See high pre ure , under pre ure. - High-speed steam- engine, a somewhat indefinite name for a reciprocating engine working at a high speed as compared with the much slower speed of engines with the Corli and other High-speed Steam-engine. types of valve-gears. In general it may be said that engines of considerable power, making one hundred turns per minute and upward, are high-speed engines. Horizontal steam-engine, a steam-engine in which the piston works horizontally. Inclined-cylinder steam engine, a form of marine engine having cylinders inclined to the horizontal. - Inverted-cylinder steam-engine, a steam-engine in which the cro -head is placed below the cylinder. This construction is much used for marine engines, and to some extent for stationary engines. - Low pre ure steam-engine. See low pre ure , under pre ure.-Marine steam-engine, a steam-engine specially designed for marine propulsion. The best modern types are condensing, short-stroke, double, triple, or quadruple expansion-engines of the inverted-cylinder type. Marine engines for steam-tugs are for the most part single and often non-condensing. See cut in next column.- Non condensing steam-engine, an engine that exhausts its steam without condensation. See non -condensing. Oscillating steam-engine, a steam-engine whose cylinder oscillates on trunnions and has its piston-rod directly connected with the crank. Double engines of this type have been considerably used for marine propulsion, and some are still employed. - Overhead steam-engine. See over head.-Quadruple expansion steam-engine, a steam engine which, taking its steam at high pre ure, expands it in four different operations succe ively, and in four distinct and separate steam-cylinders. The pistons of the cylinders are connected by piston-rods, cro -heads, and connecting-rods with cranks attached to a common shaft, to which rotary motion is imparted by the coacting pistons.Reciprocating steam-engine, a steam-engine in which the power of steam is applied to a reciprocating piston.Revolving-cylinder steam-engine, a steam-engine of which the cylinder is so mounted that it is caused to rotate by the reciprocation of the piston. Compare rotary steam engine.Rotary steam-engine, a steam-engine in which the piston rotates in the cylinder, or the cylinder upon the Steam-gage (Ashcroft's). a, hollow bent tube attached to case at a ' , and receiving condensed water or steam under pre ure through the opening at f; b , link connecting end of tube a with short arm of rock lever c , which has at the upper end a small rack intermeshing with a pinion on the spindle of the index d , e, small coiled spring which acts upon the spindle of the index or pointer in a direction opposed to the action of the rack and pinion; g , dial, on which the figures indicate pre ures (in pounds) above the atmospheric pre ure.