How to inspect and judge the hydraulic cylinder parts’ quality?

In hydraulic systems and diverse machines, the significance of hydraulic cylinder quality cannot be overstated. Hydraulic cylinders comprise numerous components, thus it is imperative to scrutinize their quality to guarantee the overall quality of the hydraulic cylinder. This write-up outlines the process of inspecting hydraulic cylinder components.

(1) The inner diameter of the hydraulic cylinder barrel

The hydraulic cylinder barrel is referred to as the hydraulic cylinder tube, and it is essential that the inner diameter surface is exceptionally smooth and uniform, with a maximum roughness of Ra 0.4 microns. In the event of minor linear friction scratches or spot marks, they are permissible and pose no harm during use. If there is a longitudinal strain, the inner hole must be ground or smoothed out with fine sandpaper or a whetstone. However, if the longitudinal strain cannot be remedied, the hydraulic cylinder tube must be replaced with a new one.

(2) Hydraulic Piston rod

Hydraulic piston rod is mostly manufactured from chrome rod for hydraulic cylinders, it is one of the most popular applications of chrome plated bar, some times it also known as chrome plated shafting

When there is damage or scarring on the sliding surface of the hydraulic piston rod that moves in relation to the sealing ring, the method of assessment and treatment is the same as for the inner surface of the hydraulic cylinder barrel. However, since the sliding surface of the hydraulic piston rod is often plated with hard chrome, it is important to note that if any part of the coating wears off and creates deep longitudinal marks, there may be significant external oil leakage. In such cases, the old coating must be removed, and the rod must be re-chromed and polished. Typically, the hard chrome plating thickness on the shafting ranges from 0.02mm to 0.05mm, as requested.

(3) Hydraulic Seals

Initially, inspect the piston rod and piston seal by examining the condition of the seal’s lip and the degree of wear on the sealing friction surface. If there are any minor marks on the lip or signs of wear on the friction surface, it is advisable to replace the seal with a fresh one.

(4) Guide sleeve

Scarring on the guide sleeve’s inner surface has minimal impact on its functionality. Nonetheless, if the scar exceeds 0.2mm, it is advisable to replace the guide sleeve with a new one.

(5) Piston

If there are minor blemishes on the piston’s exterior, it won’t hinder its functionality. However, if the imperfection exceeds 0.2mm, it’s necessary to swap out the piston for a new one. Additionally, inspect the piston for any fractures resulting from contact with the cylinder head. If any cracks are present, it’s imperative to replace the piston.

(6) Other parts

The examination of other components depends on the design and function of the hydraulic cylinder. Nevertheless, it is crucial to scrutinize the end cover, earrings, hinge shaft for any cracks, and inspect the piston rod’s top thread and oil port’s thread for any abnormalities.

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