Abstract: The embodiments disclosed herein provide a check valve aspirator including a venturi pipe having a converging section with a converging inlet and a converging outlet, and a diverging section with a diverging inlet and a diverging outlet. The converging outlet is in fluid communication with the diverging inlet. An outlet channel is in fluid communication with the venturi pipe and has an outlet port.

Abstract: A fluid power apparatus having a housing with a bore therein which is divided by a power piston into an inlet chamber and an outlet chamber. The power piston has a passageway for connecting the inlet chamber with an outlet chamber. A valve arrangement controls the flow of a fluid under pressure from a source through the passageway. The valve arrangement including a valve seal, a valve spring and an input rod. The valve spring urges the valve seal into engagement with the input rod to define a working chamber within said passageway. The fluid under pressure flows from the inlet chamber to the outlet chamber by passing between the valve seal and a valve seat located in the working chamber. The flowing of fluid past the valve seat in a rest mode of operation develops a turbulence which creates a broad band non-resonance sound having an acceptable audible level of approximately 30 dB.