Abstract: An electric motor driven pump for pumping a hazardous liquid includes an electric motor having a housing, energizing means surrounded by the housing and a rotatable output shaft extending from the housing. The housing contains a non-hazardous liquid that displaces oxygen in the housing so that explosions due to an electrical spark caused by failure of the electric motor is resisted. The pump further includes an impeller connected to the output shaft for pumping the hazardous liquid and an outer shell surrounding the electric motor. The outer shell and the electric motor define an outer space which contains an inert atmosphere and which isolates the electric motor from the hazardous liquid that is being pumped. In this way, explosions due to an electrical spark caused by failure of the electric motor and the presence of a hazardous liquid vapor are further resisted.

Abstract: A protection system to prevent the failure of a flywheel caused by an overspeed condition of a fluid pump. A positive displacement pump is coupled to, and driven by, the drive shaft of the fluid pump, and the positive displacement pump circulates a fluid into a discharge manifold. The fluid exits from the discharge manifold through an orifice, and returns to the positive displacement pump to be recirculated. Brake shoes are arrayed around the flywheel, and are connected to hydraulic cylinders, which in turn is connected by conduits to the discharge manifold. A pressure sensitive valve is installed in the conduit between the discharge manifold and the hydraulic cylinder. The pressure sensitive valve permits fluid to flow from the discharge manifold to the hydraulic cylinder whenever the pressure within the discharge manifold exceeds a predetermined level.