| CPC F16K 7/17 (2013.01) [F16K 7/12 (2013.01); F16K 31/1221 (2013.01)] | 16 Claims |

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1. A differential pressure driven diaphragm valve with separated drive chamber and valve actuation chamber, comprising:
a piston assembly, comprising an axially movable drive rod and a piston plate fixed on the axially movable drive rod, wherein an upper surface of the piston plate is provided with a groove for a plurality of eccentrically arranged elastic bodies to abut against;
a cylinder body defining a differential pressure driven chamber, the cylinder body comprising a cylinder base and a cylinder cover fixedly connected to each other in a threadedly snap connection manner, wherein the piston plate is subjected to an upper differential pressure and a lower differential pressure, so as to be lifted or lowered in the differential pressure driven chamber to synchronously lift or lower the axially movable drive rod; the plurality of eccentrically arranged elastic bodies are provided in the cylinder cover; the piston plate is positioned in the differential pressure driven chamber; the plurality of eccentrically arranged elastic bodies are configured to have a preset elastic stroke, so that the plurality of eccentrically arranged elastic bodies do not provide an elastic force at a beginning of screwing of the cylinder cover with the cylinder base; and a first end of the axially movable drive rod is positioned in a central hole of the cylinder cover, and a second end of the axially movable drive rod is configured to pass through the cylinder base and a valve cover;
a valve body defining a valve actuation chamber, the valve body comprising a valve base and the valve cover combined with each other, wherein the cylinder base is fixedly connected to the valve cover by indirect screw connection near a shaft center and radial convex-convex limiting at a shaft periphery of a shaft;
a diaphragm piece positioned in the valve actuation chamber and configured for blocking a first flow passage and a second flow passage in the valve base, wherein a non-rotatable connection relationship is formed between a periphery of the diaphragm piece and at least one of the valve cover or the valve base;
a diaphragm press block positioned in the valve actuation chamber, the diaphragm press block configured for pushing the diaphragm piece to achieving blocking; and
a shaft coupler configured for connecting the second end of the axially movable drive rod with a central connecting portion of the diaphragm piece so that a non-rotatable connection relationship is formed between a center of the diaphragm piece and the shaft coupler, wherein the shaft coupler is detachably positioned inside the diaphragm press block and positioned on the diaphragm piece, so that a relatively rotatable connection relationship is formed between the shaft coupler and the axially movable drive rod, and a non-rotatable connection relationship is formed between the shaft coupler and the diaphragm press block; wherein the diaphragm press block has a plurality of peripheral teeth, and the valve cover has a plurality of longitudinal guide grooves for guiding sliding of the plurality of peripheral teeth, so that a non-rotatable and relatively liftable limiting relationship is formed between the diaphragm press block and the valve cover.
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