Over-pressure protection of a fluid sensor

摘要

Apparatus for protecting a fluid sensor against excess fluid pressure that includes a manifold having an internal fluid passage and a fluid inlet for connecting the passage to a fluid system. A piston is disposed within the passage adjacent to one end of the passage, and a rod extends from the piston through the passage. A valve is coupled to the rod at a position spaced from the piston, and is cooperable with the passage for selectively terminating fluid flow through the passage. A fluid sensor may be mounted on the manifold for communicating with fluid in the passage at an end thereof adjacent to the valve and remote from the piston. A spring resiliently engages the piston and urges the piston, rod and valve toward the end of the passage to open the valve. Fluid pressure at the inlet sufficient to overcome forces applied to the piston by the spring functions to close the valve and thereby to isolate the sensor from the fluid inlet.