It can be integrated into the system as devices in their own right, or integrated into pump units or reservoir units as valve combinations.

Its are categorized on the basis of their function in the centralized lubrication system:

Directional control valves
ball valves, conical seat valves or piston port controls in grease pumps
 

Check valves
Relief valves
sleeve, piston and ball valves

Pressure control valves
ball valves, conical seat valves with elastic seals, piston valves with elastic sealing ring
Pressure-limiting or overpressure valves
ball, piston and conical seat valves
 

Shutt-off valves
ball valves

Technical features:

Lubricant: oil,  greases up to NLGI grade 2

Ambient temperature: -25 to +80 °C

Pressure:
    up to 45 bar for use in single-line lubrication systems
    from 300 to 500 bar for use in progressive lubrication systems

Special features:

Different drives available:
    electrically operated
    hydraulically operated
    pneumatically operated