External Pressure Difference

FD50 Forklift work for some time, the working device with load decreases, the hydraulic oil often ejected from the tank respirator, accompanied by the sound of steam spray outside.
This type of forklift hydraulic oil tank for the industry-wide open structure, the gas tank to the atmosphere through the respirator, when the return pipe back to the oil, the fuel tank of the excess air through the respirator discharge. Because preliminary analysis of fuel injection apparatus insufficient ventilation, but remove the respirator work for some time, the problem still exists. Remove the oil filler cap test, working for some time the hydraulic oil ejected from the oil filler cap.
This type of forklifts oil tank structure as the original photo (a) below. The brake pump, steering, multi-way valve and return pipe mast cylinder ports are arranged above the liquid level in the hydraulic oil, and the suction nozzle is on the steel pipe. The scene observed that when the working device with load drops, a lot of oil quickly back to the oil return pipe in the mouth by suction after the high-speed, wherein the formation of intense splash. After the hydraulic oil temperature, fuel tank will produce large amounts of oil droplets and oil mist, so that a sharp increase in air pressure inside the tank. These fluids, oil droplets and oil mist, and ultimately through the respirator quickly discharged. As the blocking filter, oil droplets and oil mist through the respirator filter when piled on in the fuel tank, under the action of external pressure difference, so that the hydraulic oil ejected from the ventilator speed.

As the forklifts above problems exist, the research, we decided on the return pipe to the hydraulic tank re-arranged location. Improved hydraulic tank structure such as the photo (b) below, as follows: The oil return pipe back to the frequent brake pump, steering return line and multi-way valve arranged in the return pipe full hydraulic oil below the liquid level, the back to the suction port and the location of each staggered back as far as possible to widen the distance from the port and respirator.
The type of cargo truck re-arranged the return line after the frequent return of the three oil ports in the back below the liquid level to avoid high impact oil return suction oil droplets or oil mist arising from the fuel tank respirator injection disappears. In addition, this improvement of the hydraulic components also play a protective role, but also to extend the service life of hydraulic oil.