Patent ID: 7758014

Claim:
A miniature needle valve for fluid control comprising a valve body comprising inlet and outlet ports, a fluid passageway between said inlet and outlet ports, a body central fluid passageway perpendicular to said fluid passageway between said inlet and outlet ports, an annular sealing surface between the outlet fluid passageway and said body central fluid passageway, a valve body sealing surface above said fluid passageway between said inlet and outlet ports, a valve bonnet with threaded engagement with said valve body for axially moving said bonnet against a portion of said valve body sealing surface, a valve stem having threaded engagement with said valve bonnet and movably mounted in relation to said annular sealing surface for moving said valve stem toward and outwardly from said annular sealing surface, and a compressible valve seal between said valve stem and said valve bonnet in order to prevent a loss of fluid past said valve stem, and said valve further comprising: a bonnet-to-body metal-to-metal seal for at least reducing and preferably preventing the loss of fluid from said valve, said valve body sealing surface being internal to said valve body and below the valve body threads, and said valve body sealing surface having an annular area about equal to the minor diameter of said valve body threads and the valve bonnet bore; and a dovetail undercut between said valve body sealing surface and said annular sealing surface for relieving stress on said valve body sealing surface when the contact forces of said bonnet exceed the amount of force required in order to effect a seal, while remaining an effective distance away from said bonnet-to-body metal-to-metal seal in order to support the forces required to effect a seal; said dovetail undercut machined directly below said portion of said valve body sealing surface contacted by said bonnet in order to allow high pressure fluids to push the supporting body material of said valve body sealing surface against said bonnet for further compression of said valve body to said bonnet-to-body metal-to-metal seal.