SAFETY SWITCH FOR WELL OPERATIONS

摘要

A pressure controlled safety switch comprises an electrical switch disposed in a cavity of a mandrel. A bellows assembly is operably engaged with the electrical switch. The bellows assembly is in fluid communication with a fluid surrounding the mandrel such that a pressure in the fluid no less than a predetermined pressure causes the bellows to activate the electrical switch, and a pressure in the fluid less than the predetermined pressure causes the bellows to deactivate the electrical switch.