Wenderoth, Lind & Ponack
Pressure regulating system for a fire extinguishing facility
 In a pressure regulating system for a fire extinguishing facility, a primary side and a secondary side of a body of a pressure regulating valve is isolated from each other by a main valve. An internal valve chamber which is in communication with the primary side is formed on the back side of the main valve. Further, a pressure regulating pilot valve is formed such that a valve disk thereof is disposed so as to be pressed against a valve seat by a spring positioned within a valve chamber into which the primary pressure is introduced. The pressure receiving area of a first surface for receiving pressure in the direction of opening of valve disk and the pressure receiving area of a second surface for receiving a pressure in the valve closing direction are substantially equal to each other. 
Nohmi Bosai Ltd.
Y A Y G
Y10T A62C Y10T G05D
additional inventional additional inventional
Hitoshi
Yamada