Patent ID: 8807168

Claim:
A fluid flow control device, comprising: a supply port for receiving a supply of pressurized fluid; an output port for delivering a supply of pressurized fluid; a vent port for venting a supply of pressurized fluid; a trim cartridge disposed between the supply port and the output port and between the output port and the vent port, the trim cartridge defining a cartridge supply port and an upper planar surface, the cartridge supply port being disposed along a supply path extending between the supply port and the output port, the upper planar surface disposed along an exhaust path extending between the output port, through the trim cartridge, and then the vent port; a diaphragm assembly disposed between the output port and the vent port, the diaphragm assembly defining an exhaust port along the exhaust path; a control element movably disposed in the trim cartridge, the control element including a supply plug, an exhaust plug, and a stem extending between the supply and exhaust plugs, the supply plug in selective engagement with the cartridge supply port of the cartridge, thereby closing the supply path, the exhaust plug in selective engagement with the exhaust port of the diaphragm assembly, thereby closing the exhaust path, the exhaust plug comprising a lower planar surface disposed at an interface between the exhaust plug and the stem, wherein during the selective engagement the lower planar surface of the exhaust plug being coplanar with the upper planar surface of the trim cartridge.