Its structure compact multi-stage cylinder, in a given installation to achieve spatial than single stage cylinder longer travel, so that in the case of installation spatial tension has been widely used. Such as dump truck dump tanks, garbage station shoveling cylinders, handling equipment and other bridge in the lift cylinder cylinder. A typical use of several common multi-stage multi-stage cylinder cylinder structure is three-cylinder, and the remaining structures and works multistage cylinder can be expanded with reference to the structure and working principle of the three cylinders. This paper focuses on three cylinders, readers may rest on. Run foreign matter generated a. Because cushion plunger and the formation of other fresh friction iron or iron filings. Buffer device with the gap is very small, the piston rod cylinders suffered lateral load is large, it may cause sintering phenomenon. These friction iron or already falling off due to sintering of metal debris generated will remain in the cylinder. b. scars cylinder wall inner surface. High pressure piston sliding surface double-acting hydraulic cylinder, causing the phenomenon of electric hydraulic jack cylinder firing, then squeeze the cylinder surface cracking occurred engineering cylinder pressure test standard, pushed the metal crack off, stay in the cylinder, double-acting causes injuries Hydraulic cylinders | Hydraulic Lu (certified) | martial cylinders provided by Lu of hydraulic equipment plant in Texas. Texas Lu force hydraulic machinery plant (www.luliyeya.com) is a leader in Dezhou, hydraulic machinery and parts, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Lu Hydraulic leadership with the staff warmly welcome all inquiries negotiations to create Lu hydraulic force a better future.