Manufacturing industry equipments such as cylinders, pumps and motors needed for construction are done with thorough planning for a specific design, but sometimes these designs fail due to maintenance or life expectancy. According to statistics, about 25% of mechanical equipment fails because of its design. Assuming that this applies to hydraulic cylinders, the ratio would be one is to four for such cylinders that are not designed decently for the particular application that they are working on. Yes, it would do the job it is asked for, but not with an acceptable service life.



When seen in the manufacturer's perspective, cylinders are as typical as motors and pumps combined. If, for example, a certain industry equipment company operates a lot of hydraulic equipment, then it is likely possible that hydraulic cylinder repair costs would be on the top part of one's overall maintenance costs. If one has a cylinder that needs frequent repair, then one may need to look at design-related problems which may arise at any given time of use. Some problems include bent rods, ballooned tubes, insufficient bearing area, and rod finishing.

Bent rods are a familiar cause of rod seal failures. Such bending of cylinder rods can be caused by insufficient rod diameter or material strength, improper cylinder mounting arrangement, or the combination of all three. Once the rod bends, extra load is placed on the rod seal, therefore resulting in the premature failure of the seal. With the use of the Euler formula, the permissible rod loading for a cylinder in an application can be checked out.

Hydraulic cylinder repair is done when the ballooning of the cylinder tube occurs. This is caused by inadequate wall thickness and/or material strength for the cylinder's operating pressure. Once the tube balloons, the endurance between the tube wall and the piston seal is lost and high pressure fluid goes around the seal.

Premature failure of the seals and deformation will result when insufficient bearing area is seen. Definitely, hydraulic cylinder repair is needed for this, since excessive load is placed on the rod and piston seals. Another problem is of the rod finish, because the surface finish of the cylinder rod may have a huge impact on the life of the rod seal. If the roughness of the surface is too low, seal life can be reduced through incapable lubrication. If such surface is too high, contaminant ingression is increased, and an unacceptable level of leakage may be expected.

To be able to extend the service life of a cylinder, consider the surface of the cylinder rod as a lubricated wear surface and treat it for that reason. Alternative rod surface treatment such as black nitride or high velocity oxygen fuel metal spraying can be used in order to increase the life of the rod and its seals.