A cylinder is one of the most important components in the hydraulic system and it can ensure the efficient working of your hydraulic system. When the hydraulic cylinder fails, it can damage your entire system performance. It is the cylinder that holds heavy loads and lifts it when requires. The selected cylinder needs to be capable enough to hold the required load safely for a longer time and it needs to fit easily with your system. Under certain circumstances, the cylinder will lose the ability to hold the load and it drifts downwards. This hydraulic cylinder drifting can be a serious issue that concerns the safety and productivity of your work. More details regarding hydraulic cylinder drifts are discussed below.
In various hydraulic systems like cranes, aerial lifts, telescopic handlers, and more, the hydraulic cylinder can be locked at the desired position to avoid further upward or downward movement of the piston rod. The cylinder will drift when the hydraulic cylinder will lose this locking ability. You can consider an excavator used in the construction industry as an example. The boom, dipper, and bucket movement of the excavator are based on the operation of telescopic hydraulic cylinders. The excavator is designed by carefully selecting each of the cylinders, that satisfy the system requirements. Drifting of the hydraulic cylinder in the excavator indicates that you can no longer use the machinery effectively as they were originally designed.
Also Read: Top 5 Hydraulic Cylinder Repair Tips
What are the major reasons for hydraulic cylinder drifting? The most important reason for drifting is oil leakage at the control valve, holding valve, or rod seals and it creates an imbalance in the fluid flow. Other factors that influence the cylinder drift are overheating, contamination, improper fluid selection, and inappropriate rebuilding of the system. Excessive heat in the system will change the properties of both oil and seal and it maximizes the system wear. Contaminants like dirt, rust, air, water, etc… will resist the smooth flow of fluid through the system. Inappropriate fluid selection and wrong rebuilding of the system will also increase the risk of hydraulic system failure.
Hydraulic cylinder drift can be diagnosed by performing pressure testing under controlled conditions. Leakage in piston seal and rod seal is an indication of hydraulic cylinder drift. But, leakage occurs due to many other factors also. Another approach for troubleshooting is by evaluating the pressure gauge readings.
How to prevent hydraulic cylinder drifting? Since it is a safety concern, it is more important to prevent cylinder drift. The risk of failure can be avoided by choosing quality hydraulic cylinders and seals. It is important to perform regular maintenance on the cylinder by inspecting corrosion and component wear. Keeping the oil clean by proper filtration and oil replacement is also necessary for preventing cylinder drift.
HYDRAULIC CYLINDER DRIFT TEST
A hydraulic drift test is conducted for testing the integrity of the piston seal. This test is done by pressurizing the cylinder for understanding the leakage. The test is conducted by placing the cylinder on a stand and filling both extend and retract ports with hydraulic oil. This cylinder can be extended or retracted using a connected directional control valve. Also, the end ports need to be pressurized using a relief valve. By following this procedure, leakage around the rod seal can be identified.