1. The oil drain pipe of the hydraulic system should be connected to the oil tank separately and above the liquid level. If the drain pipe goes below the liquid level, measures should be taken to avoid siphoning, for example, a small hole can be opened in the part of the drain pipe exposed to the liquid level.

2. The main pipeline (oil suction pipe and oil return pipe), the oil suction pipe of the hydraulic pump station and the oil return pipe of the system are the main pipelines of the hydraulic system. They should enter the oil suction area and oil return area separated by the partition. The pipe end should be processed into a 45 degree bevel towards the box wall, which can increase the opening area and circulate along the box wall.

The oil return pipe orifice shall be at least 200mm below the liquid level, and the distance from it to the bottom of the oil tank shall be more than 2-3 times of the outer diameter of the oil return pipe. When the flow rate of the oil return pipe is too high, an oil tank shaped diffuser with many small holes can be installed at the end of the oil return pipe. A coarse filter shall be installed in front of the oil suction pipe to remove large particles and impurities and protect the hydraulic pump; It is recommended to install a fine filter on the oil return pipe to filter out fine particles and impurities and protect the hydraulic components.

In order to prevent the oil suction pipe from absorbing air or mixing air from the oil return pipe to avoid stirring or absorbing the sediment at the bottom of the tank, the upper edge of the pipe orifice shall be at least 75mm lower than the liquid level or twice the pipe diameter, and the lower edge of the pipe orifice shall be at least 50mm away from the high point of the tank bottom. The distance between the oil suction pipe orifice and the side wall of the oil tank shall be more than 3 times the diameter of the oil suction pipe.

3. Perforated sealing oil pipes often pass through the tank top or wall and enter the oil tank. Perforated parts shall be properly sealed. Weld a boss 20mm above the tank top at the interface to prevent the dirt on the hydraulic system tank top from falling into the tank during maintenance. If the oil pipe of the hydraulic pump station passes through the tank wall and enters the oil tank, in addition to being properly sealed, a stop valve shall be installed to facilitate the maintenance of components outside the oil tank.