8.3.3 Dosing valves

Needle valve (standard design):
Closing action displaces an additional amount of adhesive (can be minimised with stroke limitation).
Only two positions: “Open” and “Closed”

Snuff-back valve:
Closing action creates a slight vacuum in the outlet needle → clean cut-off when dosing is ended.
Only two positions: “Open” and “Closed”

Proportional valve:
Control of the volume flow by varying the stroke (water cock principle).
Pinch valve
