The HH, HL, HM, HR, HG, HV, and HS hydraulic oils in the GB/T7631.2-2003 classification are all mineral oil-type hydraulic oils. There are many types of this type of oil, and the usage accounts for about 10% of the total hydraulic oil. More than 85%, the hydraulic oil commonly used in the hydraulic system of automobiles and construction machinery also belongs to this type.

HH type

HH hydraulic oil is a mineral oil without any additives. Although this oil has been included in the classification, it is not used in hydraulic systems. Because this oil has poor stability and is easy to foam, it has a short service life in hydraulic equipment.

HL type

Specification:

HL hydraulic oil is made of neutral base oil with high refining depth, plus anti-oxidation and anti-rust additives. HL hydraulic oil can be divided into six grades of 15, 22, 32, 46, 68, and 100 according to the kinematic viscosity at 40°C.

Application: HL hydraulic oil is mainly used for lubricating bearing housings, low-pressure circulation systems or similar mechanical equipment circulation systems of various machine tools where there is no special requirement for lubricating oil and the ambient temperature is above 0°C. Its service life can be more than double that of mechanical oil. This product has good rubber sealing adaptability, and its maximum service temperature is 80°C.

Quality requirements:

(1) Suitable viscosity and good viscosity-temperature performance. It is required that the viscosity of the oil is less affected by temperature changes, that is, temperature changes will not affect the normal operation of the hydraulic system.

(2) It has good rust resistance and oxidation stability.

(3) It has ideal air release value, anti-foaming property, water separation and rubber sealing adaptability.

Precautions

(l) Before use, the original hydraulic oil tank should be thoroughly cleaned to remove residual oil, waste oil and sediment, etc., and avoid mixing it with other oil products.

(2) This product is not suitable for special machine tools with harsh working conditions and high lubrication requirements. For gear transmissions, hydraulic systems and guide rails that require high oil quality, medium and heavy-duty gear oils, anti-wear hydraulic oils or HG hydraulic oils should be used.

Precautions for use:

(1) Before use, the original hydraulic oil tank should be thoroughly cleaned to remove residual oil, waste oil and sediment, etc., and avoid mixing it with other oil products. (2) This product is not suitable for special machine tools with harsh working conditions and high lubrication requirements. For gear transmissions, hydraulic systems and guide rails that require high oil quality, medium and heavy-duty gear oils, anti-wear hydraulic oils or HG hydraulic oils should be used. (3) This oil replaces mechanical oil for the lubrication of the circulation system of general-purpose machine tools and other similar mechanical equipment. It has significant economic benefits, can extend the oil change cycle, and saves lubricating oil by 1/3-1/2 on average.