Patent ID: 7188531

Claim:
Pressure gauge adapter for use in connection with a sanitary conduit through which a liquid product flows whose pressure is to be monitored, the conduit including a tubular stub formed on said conduit to mount a pressure gauge and to permit communication of pressure to said gauge from said fluid; and wherein said pressure gauge has a body portion and a male threaded stem for attaching to a female-threaded gauge fitting; the adapter comprising: a flange member of a diameter to mate with an upper flange of said tubular stub; seal means disposed between said flange member and the flange of said tubular stub; clamp means for removably holding said flange member in sealed engagement with said tubular stub; a cylinder having a hollow cylindrical wall rising from said flange member and a cap closing off an upper end thereof, including an aperture through said cap; a female threaded nipple affixed on said cap over said aperture, the nipple having a female thread adapted to accept the male threaded stem of said pressure gauge, such that the nipple serves as said gauge fitting; a piston fitted within said cylinder including a seal ring for sealably engaging said hollow cylindrical wall but permitting limited axial motion of the piston; and a fill of a non-compressible pressure transmitting medium within said cylinder above said piston, and within said nipple; wherein said piston has an upper seal ring and a lower seal ring seated in parallel spaced relation to one another defining an annular space therebetween; and wherein said cylinder has an aperture through said cylindrical wall at a position aligned with the annular space of said piston, for providing a visual indication of leakage in the case of failure of either of said upper ring or said lower seal ring.