Finger-Tight Gas Chromatograph (GC) Column Connections
A gas chromatograph (GC) column connection device includes a housing including first and second opposite ends, the housing including a housing bore extending therethrough between the first and second ends of the housing. The device includes: a piston in the housing bore; a ferrule at least partially in the housing bore at a second end of the piston; a biasing mechanism in the housing bore at a first end of the piston; and a retaining member in the housing bore between the first end of the housing and the biasing mechanism, with the retaining member spaced apart from the first end of the housing. The retaining member is configured to retain the biasing mechanism such that the biasing mechanism urges the piston axially toward the second end of the housing.
1 . A gas chromatograph (GC) column connection device comprising:
a housing comprising first and second opposite ends, the housing comprising a housing bore extending therethrough between the first and second ends of the housing;
a piston in the housing bore, the piston comprising first and second opposite ends;
a ferrule at least partially in the housing bore at the second end of the piston;
a biasing mechanism in the housing bore at the first end of the piston; and
a retaining member in the housing bore between the first end of the housing and the biasing mechanism, the retaining member spaced apart from the first end of the housing, the retaining member configured to retain the biasing mechanism such that the biasing mechanism urges the piston axially toward the second end of the housing.
2 . The device of claim 1 wherein:
the housing comprises a first housing portion and a second housing portion,
the piston is in the second housing portion,
the first housing portion comprises a flange extending radially outwardly away from the second housing portion, and
the first housing portion comprises a sidewall extending from the flange to the first end of the housing.
3 . The device of claim 2 wherein:
the housing bore comprises a first housing bore and a second housing bore in fluid communication with the first housing bore,
the first housing bore is defined by the flange and the sidewall,
the second housing bore is defined by the second housing portion, and
the biasing mechanism and the retaining member are in the first housing bore.
4 . The device of claim 3 further comprising:
an annular groove in an inner surface of the sidewall, wherein the retaining member is in the annular groove.
5 . The device of claim 4 wherein:
the first housing bore comprises tapered portion between the first end of the housing and the groove,
the first housing bore comprises a constant diameter portion between the flange and the groove, and
the biasing mechanism is held in the constant diameter portion.
6 . The device of claim 5 wherein the tapered portion of the first housing bore decreases in diameter toward the groove such that, when the retaining member is inserted into the first housing bore, the retaining member is compressed by a ramped portion of the sidewall and then snaps into place in the groove thereby providing audible and/or tactile feedback.
7 . The device of claim 3 wherein the biasing mechanism is a single conical spring washer.
8 . The device of claim 7 wherein the sidewall is free of apertures, channels, or voids extending therethrough.
9 . The device of claim 7 wherein the flange comprises at least one aperture extending therethrough.
10 . The device of claim 7 further comprising a grip on the sidewall configured for hand-tightening the device to a detector or injector of a gas chromatograph, wherein an outer surface of the sidewall is optionally knurled.
11 . The device of claim 7 wherein the piston comprises a primary body and a stop extending radially outwardly from the primary body with the stop at the flange, the piston further comprising a projection extending from the stop toward the first end of the housing, and wherein the conical spring washer surrounds the projection with the projection received in a bore of the conical spring washer.
12 . The device of claim 3 wherein the biasing mechanism comprises a plurality of conical spring washers.
13 . The device of claim 12 wherein:
the sidewall is a first sidewall,
the first housing portion comprises a second sidewall extending from the flange to the first end of the housing, the second sidewall spaced apart from and surrounding the first sidewall.
14 . The device of claim 13 wherein the first sidewall and/or the second sidewall is/are free of apertures, channels, or voids extending therethrough.
15 . The device of claim 2 wherein an outer surface of the second housing portion is threaded at the second end of the housing such that the device can threadingly engage a detector or injector of a GC.
16 . The device of claim 1 further comprising a GC column extending through respective bores of the retaining member, the biasing mechanism, the piston, and the ferrule.
17 . The device of claim 16 wherein:
the ferrule comprises a tapered outer surface, and
compression of the tapered outer surface of the ferrule and a surface of a detector or injector of a GC compresses the ferrule against the GC column.
18 . A method for connecting a gas chromatograph (GC) column to a detector or injector of a GC, the method comprising:
providing a GC column connection device comprising:
a housing comprising first and second opposite ends, the housing comprising a housing bore extending therethrough between the first and second ends of the housing;
a piston in the housing bore, the piston comprising first and second opposite ends;
a ferrule at least partially in the housing bore at the second end of the piston;
a biasing mechanism in the housing bore at the first end of the piston; and
a retaining member in the housing bore between the first end of the housing and the biasing mechanism, the retaining member spaced apart from the first end of the housing, the retaining member configured to retain the biasing mechanism such that the biasing mechanism urges the piston axially toward the second end of the housing;
inserting a GC column through respective bores of the retaining member, the biasing mechanism, the piston, and the ferrule;
threadingly engaging the second end of the housing with a detector or injector of a GC such that the GC column extends into an interior of the detector or injector; and
rotating the housing relative to the detector or injector to form a fluidic seal between the ferrule and the piston and between the ferrule and a surface of the detector or injector.
19 . The method of claim 18 wherein:
the housing bore is at least partially defined by a sidewall at the first end of the housing,
an annular groove is defined in the sidewall,
the sidewall comprises a ramped portion between the first end of the housing and the annular groove,
the method further comprises assembling the GC column connection device comprising:
receiving the piston in the housing bore; then
receiving the biasing mechanism in the housing bore; then
receiving the retaining member in the housing bore; then
urging the retaining member in the housing bore toward the biasing mechanism;
compressing the retaining member using the ramped portion of the sidewall in response to the urging; and then
receiving the retaining member in the annular groove.
20 . A gas chromatograph (GC) column connection device comprising:
a housing comprising first and second opposite ends, the housing comprising a housing bore extending therethrough between the first and second ends of the housing, the housing bore defining a longitudinal axis;
a piston in the housing bore, the piston comprising first and second opposite ends;
a ferrule at least partially in the housing bore at the second end of the piston;
a biasing mechanism in the housing bore at the first end of the piston, the biasing mechanism comprising a conical spring washer;
a retaining member at the first end of the housing and configured to retain the biasing mechanism such that the biasing mechanism urges the piston axially toward the second end of the housing; and
a plurality of fasteners each extending parallel to the longitudinal axis through the retaining member and into the housing, wherein the fasteners do not engage the conical spring washer.