Modern American locomotive engines; their design, construction and management. A practical work for practical men (1883)
Edwards, Emory, b. 1841 · Bridgeport, Conn., Frederick Keppy · leaf 194
valve at each end overlapsthe steam ports (see Fig. 56) when placed exactly overthem is technically termed the lap. The lap of thevalve being three-eighths of an inch, the exhaust pas-sage was about three-eighths of an inch open whenthe stroke was finished. LAP. The importance of putting lap upon a… … Fig. 57. result would be that the steam port could only be per-fectly closed at the precise instant when the valve wasin the middle of its stroke and moving most rapidly.From what has been said it is apparent that a valve ofthis kind (one without lap) is unsuitable for an engine,the better plan…
Locomotives
Internet Archive · Northeastern University Library · Public Domain Mark 1.0. Free to use for anything.
