Patent ID: 8106313

Claim:
A tubular body, comprising: a first end and a second end; a first opening at the first end; a second opening at the second end; a passage between the first opening and the second opening defining an interior region of the tubular body; and first threads positioned on an exterior surface of the tubular body; wherein the first opening is dimensioned for receipt of a compressible plug comprising at least one bore; wherein the first threads are configured to threadenly engage a cap unit so that as the cap unit is threaded onto the first threads the cap unit is configured to urge the compressible plug towards the second end of the tubular body; wherein a first diameter of the passage at a first position is larger than a second diameter of the passage at a second position to provide a tapered section of the passage between the first position and the second position; wherein the tapered section of the passage is configured to compress at least a portion of the compressible plug so that a cross-sectional area of the at least one bore is decreased as the cap unit is threaded onto the first threads of the tubular body; wherein the compressible plug is substantially cylindrical and comprises a first side and a second side opposite the first side, wherein the at least one bore runs from the first side to the second side of the compressible plug; and wherein the compressible plug comprises at least one slot positioned on the first side and dimensioned for receipt of a protrusion of a ring washer, wherein the ring washer has an outer diameter substantially equal to a diameter of the compressible plug and the ring washer has an inner diameter smaller than the outer diameter.