Patent ID: 6019121
Filing Date: 2000-02-01
Classification: G05D,H03L,Y10S,Y10T

Abstract:
A pressure reducing valve comprising:a body unit (32) formed to have a rectangular parallelepiped-shaped configuration and have a plurality of pressurized fluid inlet/outlet ports (66, 68);a bonnet unit (36) integrally coupled to an upper portion of said body unit (32);an operating unit (38) having a handle (126) provided rotatably on an upper portion of said bonnet unit (32);a first diaphragm (84), a second diaphragm (86), a third diaphragm (100), and a fourth diaphragm (102) provided to extend in said body unit (32) while being separated from each other by predetermined spacing distances; anda nozzle-flapper mechanism having a nozzle (106) and a flapper (110) arranged in a diaphragm chamber (116) formed between said second diaphragm (86) and said third diaphragm (100), for opening and closing a nozzle hole in accordance with an action of a nozzle back pressure in a nozzle back pressure chamber (108), wherein:said body unit (32) comprises a primary port (66) on a primary side for connection to a pressurized fluid supply source, a secondary port (68) on a secondary side for supplying a pressurized fluid with a pressure reduced to have a predetermined pressure value, to a pressurized fluid-driven apparatus, a bleed port (64) for discharging an excessive pressurized fluid supplied from said primary port (66), and an exhaust port (62) formed separately and independently from said bleed port (64), for discharging said pressurized fluid on said secondary side having a pressure higher than a preset pressure; andsaid diaphragm chamber (116) is formed so that it is excluded from pressure on said secondary side by said third diaphragm (100) and it communicates with atmospheric air via said bleed port (64), and when said pressurized fluid on said secondary side has a pressure higher than said preset pressure, said pressurized fluid in said nozzle back pressure chamber (108) is directly discharged to atmospheric air by the aid of said nozzle-flapper mechanism and said bleed port (64).