SKF Mono-Flex single-line centralized lubrication systems with single-line distributors generally consist of a lubrication unit, the single-line distributors, and the lubrication lines. The pressure regulating valve and pressure relief valve required for the single line centralized lubrication system’s operation are normally integrated into the lubrication unit.

If pressure losses of greater than 10 bar are expected in the single-line centralized lubrication system, for example, due to expansion of the system or due to the viscosity of the lubricant (depending on the ambient temperature), a pressure switch should be mounted to monitor the system at the end of the main line, if possible. The pressure-switch monitors whether the required pressure build-up occurs in the single-line centralized lubrication system during the lubrication cycle.

The lubrication unit run time specified by the control unit or machine control unit ensures pressure build-up in the single-line centralized lubrication system. The pressure in the main line must be relieved after the lubrication unit is switched off to ensure proper functioning of the single-line distributors.

This is performed by the pressure relief valve integrated into the lubrication unit. See the following illustration for examples of single-line centralized lubrication systems with pre-lubrication, relubrication, and dynamic distributors.