Abstract: A pressure reducing apparatus includes a body being equipped with a first side port through which a pressure fluid is supplied and a second side port through which the pressure fluid having been reduced in pressure is discharged. Further, a feedback passage is formed, which establishes communication between the second side port and a third diaphragm chamber that faces toward a pilot valve. Additionally, a pressure fluid that flows through the second side port is introduced through the feedback passage into the third diaphragm chamber, whereby a third diaphragm is pressed upwardly against an elastic force of a second spring into equilibrium.

Abstract: A pressure reducing apparatus includes a body being equipped with a first side port through which a pressure fluid is supplied and a second side port through which the pressure fluid having been reduced in pressure is discharged. Further, a feedback passage is formed, which establishes communication between the second side port and a third diaphragm chamber that faces toward a pilot valve. Additionally, a pressure fluid that flows through the second side port is introduced through the feedback passage into the third diaphragm chamber, whereby a third diaphragm is pressed upwardly against an elastic force of a second spring into equilibrium.

Abstract: The air (atmospheric air) is introduced from an atmospheric port, and it is throttled to give a minute amount by means of a bleed hole. The air is introduced into a vacuum chamber via a bleed passage, and it is introduced into a pressure regulator port via a feedback passage. Further, the air is allowed to pass through a space between a seat section and a seal member of a valve plug, and it is drawn toward a vacuum port. Thus, the seal member of the valve plug to be seated on the seat section is prevented from biting into the seat section.