It is standard pruoduct the standard is JB/ZQ4181-1997.This seriesbelongs to heavy-duty hydraulic cylinder. Which is specitically designed for metallurgy & heavy-duty machinery. Because of their functional reliability, good impact and pollution resistance , they  apply to high-temperature , high-pressure and rugged environment.Nowadays.They widely used in metallurgy , roll, ship, aerospace, transport and power equipment.

Cylinder and cylinder of the advantages and disadvantages:
1. As the pneumatic system uses pressure is generally in the range of 0.2-1.0Mpa, so the cylinder is the driving force can not do high-power components. Hydraulic cylinders can be done relatively large power device, use the hydraulic system;
2. From the media about the air can be unlimited, no cost and supply difficulties, the gas will be used directly into the atmosphere, convenient, no pollution, hydraulic oil is the opposite;
3. The air viscosity is small, the resistance to less than the hydraulic oil;
4. But the air is much larger than the compression rate of hydraulic oil, so it's working smoothly and to respond to far backward in this regard.
Hydraulic cylinder hydraulic system is the most important components of implementation, it can convert mechanical energy of hydraulic and matched with a variety of transmission to complete all of the mechanical movement. Hydraulic cylinder has a simple structure, the output force, stable and reliable performance and easy maintenance, wide range of applications and so on.