Valve assembly

摘要

A valve assembly has a valve body with a bore formed therein. A valve spool is slidably disposed in the valve body. The valve spool has a plurality of valve lands that closely engage the valve bore to form substantially leak-free interfaces. The leading land has a diameter less than the land immediately adjacent thereto in a range of 0.34 mm to 0.17 mm, and a recess formed between the leading land and the first adjacent land. The recess has an inner diameter at least 0.75 mm less than said diameter of said leading land.