Technical Information - Fig. 119

Operation:

The upstream pressure is introduced below the valve disc, which is opposed to atmospheric pressure via a vent port above the inlet balancing piston.

The downstream pressure is introduced above the control piston, which is sized to a fixed ratio of the area of the valve disc, and also opposed to atmospheric pressure via the vent port.

The valve will then modulate the flow to maintain a fixed relationship (eg. 5:1) between the upstream and downstream pressures, governed by the ratio of the respective areas of the valve disc and the control piston.

The Fig 119 ratio reducing valves are a type of pressure regulator that reduce high inlet pressure to a lower, stable outlet pressure at a fixed ratio.

Ratio valves provide consistent and accurate pressure reduction, ensuring that the downstream pressure remains stable and predictable.