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:
“A good scientist is a person with original ideas. A good engineer is a person who makes a design that works with as few original ideas as possible. There are no prima donnas in engineering.”
—Freeman Dyson (b. 1923)
“I have ever deemed it fundamental for the United States never to take active part in the quarrels of Europe. Their political interests are entirely distinct from ours. Their mutual jealousies, their balance of power, their complicated alliances, their forms and principles of government, are all foreign to us. They are nations of eternal war.”
—Thomas Jefferson (1743–1826)