Design Principles
When on the move, a steam locomotive requires steam to enter the piston at a controlled rate. This entails controlling the admission and exhaustion of steam to and from the cylinders. Steam enters and leaves the valve through a steam port, usually at the middle position of the piston valve. Where the valve is in contact with the steam ports, a consideration of the "lap" and "lead" is required.
Read more about this topic: Piston Valve (steam Engine)
Famous quotes containing the words design and/or principles:
“You can make as good a design out of an American turkey as a Japanese out of his native stork.”
—For the State of Illinois, U.S. public relief program (1935-1943)
“Amidst the downward tendency and proneness of things, when every voice is raised for a new road or another statute or a subscription of stock; for an improvement in dress, or in dentistry; for a new house or a larger business; for a political party, or the division of an estate;Mwill you not tolerate one or two solitary voices in the land, speaking for thoughts and principles not marketable or perishable?”
—Ralph Waldo Emerson (1803–1882)