Hydraulic tank design points

Hydraulic tank design points:

1. Tank structure:
Generally made of corrosion-resistant steel, and must consider the inner surface of the tank anti-corrosion treatment, and take into account the compatibility with the medium, the processing after treatment and the economy of manufacturing, the use of stainless steel is the most ideal choice when conditions permit.
The oil tank must have enough volume, on the one hand, to meet the requirements of heat dissipation, on the other hand, when the hydraulic system stops working, it should be able to accommodate all the working media in the system, and maintain the appropriate liquid level when working. Therefore, the tank structure design needs to have the following characteristics, the following description for its components:
(1) Tank body: thickness 3 ~ 4mm, if the tank volume exceeds 320L, the thickness should be 4~6mm, the side wall must be installed oil level gauge to control the actual oil level height.
(2) Maintenance cover: Design one or more maintenance covers on the side wall of the body, which must be assembled with close pads and bolts to avoid leakage. Its main function is easy to clean the filter and the Fuel Tank.
(3) Bottom of the box: welded with the wall panel in a inclined way, and installed at the lowest oil drain to facilitate oil drainage.
(4) The suction pipe and return pipe should be inserted below the lowest liquid level to prevent air bubbles from suction and return oil spatter. The distance between the pipe mouth and the bottom and the wall of the box is not less than 3 times the diameter of the pipe.
(5) Tubing: In the hydraulic system, as a pressure control valve and other components of the oil drainage function, the design must be careful not to insert the oil, to prevent back pressure on the system.
(6) The return pipe mouth must be cut at a 45° Angle and face the box wall, increasing the cross-sectional area of the return pipe mouth, which can slow down the flow rate to prevent the sediment impacting the bottom of the box.
(7) The end of the suction pipe can be installed with a 100μm mesh filter to prevent large foreign bodies from being sucked into the system, and the installation position must be conducive to the cleaning and disassembly of the filter.
(8) Air breathing apparatus: air filter must be installed on the vent hole to prevent negative pressure of the tank, and its capacity is at least 2 times the rated flow of the hydraulic pump.
(9) Oil tank cover: the thickness is 3 to 4 times the thickness of the body wall, made into a concave shape to avoid leakage and pollution of the upper component, and drill holes on the cover (including the outlet oil pipe hole, the oil injection port, the vent hole and the installation hole of the hydraulic integrated device, etc.).
(10) Separator: separate the oil absorption and oil return area, increase the oil return path, which is conducive to the precipitation of oil impurities, bubble separation and heat dissipation. Its height should be at least 1/2 of the lowest oil level, the highest should not exceed 3/4 of the highest oil level, and the thickness should be equal to the thickness of the body wall. If the forced oil-air separation design is considered, the partition height is the same as the liquid level, and a 5mm2 mesh stainless steel mesh is installed at the bottom 1/3 to achieve the effect of forced oil-air separation when the oil passes through.
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2. Volume calculation:
The volume of the tank is related to the flow of the system, generally in the case of intermittent operation, its volume is 3 times the maximum flow of the pump (5 times the fire protection type hydraulic oil), such as the pump can provide a maximum flow of 50L per minute, then the tank volume must be 150L. If it belongs to continuous operation, its volume must be twice or even three times more, that is, 200~300L. If the volume is less than 1000L, the shape and basic size of the fuel tank can be designed according to DIN24339; The volume is more than 1000L, and its length-width-height ratio is designed in the range of 1:1:1 to 3:2:1, and the reinforcement plate can also be considered to increase the rigidity. Its formula is as follows:
Vtot=n×Q
Where: Vtot: tank volume (L) Q: maximum oil supply by pump (L) n: multiple (mineral oil n=3, fireproof hydraulic oil n=5).

3. Other important items:
(1) A magnetic block should be installed in the oil return concentrated part of the tank and near the cleaning port to absorb the iron filings and magnetic particles in the oil
(2) For convenient transportation and installation, large and medium-sized fuel tanks should be equipped with lifting lugs.
(3) The oil temperature is recommended to work in the range of 30 to 50 ° C, the maximum should not exceed 60 ° C, the minimum is not less than 15 ° C.