After using the pile driver for a period of time, you may notice a change in the color of the cylinder. Initially, it is blue, but over time, the color may deepen to purple or even black. What causes the pile driver cylinder to change color?

1. High Temperature in the Hydraulic System: The pile driver's hydraulic system can reach high temperatures, especially in winter. During operation, the piston rod works at high temperatures and frequently contacts the low-temperature external environment.

2. Use of Non-Specialized Hydraulic Oil: While everyone may have the habit of daily maintenance, using hydraulic oil not specifically designed for pile drivers can cause discoloration within a few days. This is because different brands and types of hydraulic oil have varying qualities and performances in their extreme pressure and anti-wear additives.

3. Analyzing Discoloration by Color: The color of the discoloration can help roughly analyze the cause. Blue discoloration is due to additives in the oil seal and hydraulic oil adhering to the cylinder rod at high temperatures. Black discoloration is caused by additives containing lead in the wear-resistant sleeve material, which adhere to the cylinder rod at high temperatures.

Therefore, we can see that the cylinder surface is actually covered with a layer of colored film, rather than it being a fault with the pile driver or the cylinder itself. It is safe to continue using the equipment.