The large hydraulic cylinders used for dam gate and other valve opening and closing applications typically are expected to last from 30 to 50 years. In recent years, however, an increasing number of hydraulic cylinders are failing in the field due to piston rod corrosion. A fairly common example is the failure of plasma spray coated piston rods cited by the U.S. Army Corps of Engineers Engineering Construction bulletin on Jan 15, 2009. Unfortunately, laboratory tests do not predict the complete failure modes for these brittle mechanically bonded coatings.
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