Phosphate ester
Fire-resistant hydraulic fluid based on esters of phosphates. It belongs to the group known as HFD fluids ; its fire resistance is can be explained by its molecular structure.
Reservoir expansion capacity
Gas (air) volume above the maximum fluid level in a vessel that is intended to absorb the expansion in the volume as the temperature of the fluid changes (CETOP RP 100).
Breather filter
Filter on the hydraulic fluid tank that filters the air flowing in as the pump draws fluid to prevent contamination by this route. Its filtration grade should correspond to that of the oil filter.
Throttle check valve
valve and such that the hydraulic fluid flow in one direction must flow through the throttle (and is reduced in the process), while in the other direction the hydraulic fluid flows unthrottled via the check
Symbols
the function of a fluid device (not its construction design) in accordance with a standard or a key. The symbols were previously known as switching symbols. The symbols used in fluid switching technology
Hydrokinetics
the flow of fluids with low compressibility and little internal friction. In hydrokinetics, the transmission of energy mainly occurs via the kinetic energy associated with the flowing fluid. This is why
Sealing compatibility index (DVI)
materials in different hydraulic fluids that can range from shrinkage, through slight swelling, to complete dissolution of the elastomer. If the DVI of the intended hydraulic fluid is known, with the aid of diagrams
Density function of a liquid
The density of a fluid changes with temperature and pressure. It reduces with temperature and increases with pressure (Figure D 12) . The density-pressure function is determined by, among other things [...] things, the compressibility of the fluid. With β = compression coefficient ρ o = density at atmospheric pressure p a = atmospheric pressure
Capillary tube
is much greater than the diameter d. For Newtonian fluids, the flow rate through these kinds of flow resistors is mainly determined by the viscous fluid friction, geometry and pressure difference and may
Pressure head
Vertical height h in m of a column of fluid that, provided the density of the fluid is known, serves as a measure of the pressure that this column applies over the area of its base. The pressure head is