Yoshitake GP-2000 Installation & Operation Manual page 7

(4) Reduced pressure is led to the pilot diaphragm chamber [23]-1 via the sensing pipe and
reduced pressure sensing port [56]. The pilot diaphragm receives the reduced pressure to be
balanced with the spring load. The pilot valve travel is controlled by the spring load and
pressure applied to the pilot diaphragm due to variations in reduced pressure. This changes
the flow rate of fluid to the main diaphragm chamber, which controls the main valve travel to
obtain appropriate reduced pressure. (Fig. 4)
(5) When the load on the reduced side is released, pressure in the pilot diaphragm chamber raises
to close the pilot valve. Operating pressure in the main diaphragm chamber is released to the
body via the orifice, and the main valve spring presses the main valve to close. (Fig. 5)
Fig. 4
Fig. 5
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