Working liquid 7-50C-3 (GOST 20734-75) is the synthetic liquid made of a mix polysiloxane of a liquid and an organic aether with addition antiwear of an additive and inhibitors of oxidation.
Apply in hydraulic units and hydraulic systems of flying machines in a range of temperatures from-60 to +175°С it is long with overheats to 200°С, working pressure to 21 megapascal.

Colour: yellow, transparent
Viscosity index, not less: —
Density at 20°С, kg/m3, no more: 930-940
Viscosity kinematic, mm2/with, at 200°С, not less: 1,3
Viscosity kinematic, mm2/with, at 20°С, not less: 22
Viscosity kinematic, mm2/with, at-60°S, not less: 4200
Acid number, mg, no more: 0.1
Flash temperature, in an open crucible, °C, not more low: 200
Hardening temperature, °C, not above:-70
Turbidity temperature, °C, not above: —

Data on operational temperatures represent values which are guided by a structure of lubricants, and also on a scope and technology of use. Depending on a kind of mehaniko-dynamic loading lubricants change the consistence, conditional viscosity or viscosity at various temperatures, pressure and duration of operation. These changes of indicators can influence work of components.