Valve with main and auxiliary plugs - has auxiliary seat and control passage in spigot through main plug

摘要

The valve with main and auxiliary plugs has a main seat with plug working against it under the action of a movable end wall of a pressure chamber, the latter being connected by throttle passages to the inlet pressure chamber accommodating seat and plug. A control passage connects the pressure chamber to the low-pressure chamber, and contains an auxiliary plug controlled by an actuator, working against a stationary seat. The main plug (6) has in its movable end wall (10) a central lengthwise drilling (14), through which there passes an axial spigot (13), connected to the passage (19) form the main plug seat (16). This spigot contains the control passage (18) with an auxiliary plug seat (21).