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. 1887 Excerpt: ... cylinders, and the high-pressure valve at the side of its cylinder. "r horizontal engines it is more the fashion for the valves to be fore and aft of the cylinders. We recommend in all cases cylindrical valves with an expansion cylindrical valve within the larger or exhaust valve. We have worked those valves for some ...
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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. 1887 Excerpt: ... cylinders, and the high-pressure valve at the side of its cylinder. "r horizontal engines it is more the fashion for the valves to be fore and aft of the cylinders. We recommend in all cases cylindrical valves with an expansion cylindrical valve within the larger or exhaust valve. We have worked those valves for some time with great success. They are entirely equilibrium: as, for example, inde-pendently of the weight of the valve, the friction is so little that a valve nine inches in diameter when under steam can be moved direct with one hand. With large engines the high-pressure cylinder should have two valves at its outer side. The low-pressure cylinder should have four valves of the same diameter as the high-pressure cylinder. Two valves between the two cylinders and two valves at the outer side. The reason for this is that the same pattern for one valve is equally available for the remaining five. In some cases, however, it is equally wise to have two valves only sufficiently large for the low-pressure cylinder, and thus save one set of link and expansion motions at the cost of new patterns for the larger valves. When fiat side valves are used they can be double or single ported, with "plate" valves at the back;while in some examples a" gridiron" valve is used at the back of the low-pressure valve. The bottom, or front end of the cylinder, should always be made with a large boring-hole that is fitted with a cover, containing the stuffing-box of the piston-rod. The top or back end cover is very often similarly fitted, but contains the relief valve, surmounted with the usual spring, set screw, and casing. The bottom or front end relief valve being at the bottom side, or thereabouts, of the inside diameters of the cylinders. We ne...
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