Patent ID: 7721763

Claim:
A unidirectional flow valve defining an opening pressure that allows fluid to flow through the unidirectional flow valve, the unidirectional flow valve comprising: a housing having a fluid flow passageway, the fluid flow passageway defined by an orifice and an exit aperture, the housing having first and second sections threadably engaged to each other to a selective depth for adjusting the opening pressure, the orifice defined by the first section, the exit aperture defined by the second section, the first section having an inner wall and an outer wall circumscribed about the inner wall, the outer wall having internal threads and the inner wall defining the orifice periphery, the second section having a wall with external threads threadably engageable to the internal threads of the first section to the selective depth to increase or decrease a spring force of the spring until the desired opening pressure is attained; and a valve member disposed in a middle portion of the fluid flow passageway, the valve member comprising: a plug traversable between a seated position wherein the plug is in contact with a periphery of the orifice when a pressure difference between a pressure upstream to the plug and a pressure downstream to the plug is less than the opening pressure to prevent backflow of fluid and an unseated position wherein the plug is gapped away from at least a portion of the orifice periphery when the pressure difference is greater than the opening pressure; a base member being sonically welded, adhered or locked in with a collet to an upstream end portion of the second section of the housing; a spring having first and second opposed end portions, the first end portion being attached to the base, the second end portion being attached to the plug; wherein the plug and base member are selectively traversable away from each other or closer to each other as the first and second sections of the housing are threaded into each other to the selective depth to respectively increase or decrease the opening pressure until a desired opening pressure is attained.