Method of fabricating a pressurized-gas storage assembly
A pressurized-gas storage assembly has a liner defining a gas storage chamber and an end portion with a planar surface, with an access opening on the planar surface that is in fluid communication with the gas storage chamber. A raised circular ring extends from the planar surface and surrounds the access opening. The assembly also includes a polar boss having a longitudinally extending part that has a top surface with a recessed opening, and a planar bottom surface, with a channel extending through the polar boss to serve as a passageway through the polar boss. A circular groove is provided on the bottom flat surface of the polar boss, with the raised ring received inside the circular groove. An outer shell is provided around the entirety of the liner, with the outer shell having an edge-defining aperture that receives the polar boss.
1. A method of fabricating a pressurized-gas storage assembly, the method comprising:
forming a liner; comprising;
an end portion with a planar surface, with an access opening on the planar surface that is in fluid communication with the gas storage chamber, the liner further including a raised circular ring extending from the planar surface and surrounding the access opening, the raised circular ring having inner and outer side walls;
forming a polar boss which defines a longitudinally extending part that has a top surface with a recessed opening, and a planar bottom surface, with a channel extending through the polar boss and communicating with the recessed opening and terminating at the bottom planar surface to serve as a passageway through the polar boss, the polar boss further including a circular groove provided on the planar bottom surface, the circular groove having inner and outer side walls;
screwing the polar boss onto the end of the liner placing the planar surface of the end portion of the liner against the planar bottom surface of the polar boss, with the raised circular ring received within the circular groove, and the recessed opening aligning with the access opening; and,
forming an outer shell around the entirely of the liner, the outer shell having an aperture-defining edge that receives the polar boss;
wherein:
the circular groove of the polar boss is formed with a first set of helical threads provided on the inner side wall of the circular groove, and a second set of helical threads provided on the outer side wall of the circular groove;
the liner is formed without helical threads provided on the inner and outer side walls of the raised circular ring; and
the screwing of the polar boss onto the end of the liner creates a third set of helical threads on the inner side wall and a fourth set of helical threads on the outer side wall.
2. The method of claim 1 wherein the first set of helical threads, the second set of helical threads, or both comprise tapered threading.
3. The method of claim 2 wherein the tapered threading comprises a taper of about 1.79 degrees.
4. A method of fabricating a pressurized-gas storage assembly, the method comprising:
forming a liner comprising;
an end portion with a planar surface, with an access opening on the planar surface that is in fluid communication with the gas storage chamber, the liner further including a raised circular ring extending from the planar surface and surrounding the access opening, the raised circular ring having inner and outer side walls;
forming a polar boss which defines a longitudinally extending part that has a top surface with a recessed opening, and a planar bottom surface, with a channel extending through the polar boss and communicating with the recessed opening and terminating at the bottom planar surface to serve as a passageway through the polar boss, the polar boss further including a circular groove provided on the planar bottom surface, the circular groove having inner and outer side walls;
screwing the polar boss onto the end of the liner placing the planar surface of the end portion of the liner against the planar bottom surface of the polar boss, with the raised circular ring received within the circular groove, and the recessed opening aligning with the access opening; and,
forming an outer shell around the entirely of the liner, the outer shell having an aperture-defining edge that receives the polar boss;
wherein:
the circular groove of the polar boss is formed with a first set of helical threads provided on the inner side wall of the circular groove, and a second set of helical threads provided on the outer side wall of the circular groove;
the liner is formed with a third set of helical threads on the inner side wall and a fourth set of helical threads on the outer side wall; and
the screwing of the polar boss onto the end of the liner engages the first set of helical threads to the third set of helical threads and the second set of helical threads to the fourth set of helical threads.
5. The method of claim 4 , wherein the first set of helical threads, the second set of helical threads, or both comprise tapered threading.
6. The method of claim 5 , wherein the tapered threading comprises a taper of about 1.79 degrees.