High pressure gas fitting for repeated connection and disconnection

A connectable and disconnectable fitting for high seal integrity systems comprising:

• a first generally tubular member having a mating end, a fluid passage extending through the first member from the mating end and an array of external threads substantially adjacent said mating end;
• an annular metallic seal releasably disposed in sealing engagement with the mating end of the first member;
• a second generally tubular member having a mating end disposed in sealing engagement with the annular metallic seal, a fluid passage extending from the mating end of the second member and communicating with the fluid passage of the first member, a flange extending radially outwardly from the second member and having a radially aligned annular bearing surface facing oppositely from said mating end of said second member, said annular bearing surface defining inside and outside diameters;
• a continuous integrally formed annular thrust bearing mounted around said second member and having inside and outside diameters approximately equal to the respective inside and outside diameters of the bearing surface of the second member, said thrust bearing further having opposed parallel planar bearing surfaces said thrust bearings defining a thickness of approximately 0.005 inch, one said bearing surface of said thrust bearing abutting the bearing surface of the flange of the second member, said thrust bearing comprising a substrate formed from a metallic alloy having a hardness (HRC) of at least 40 and being harder than the metallic material of the second member and a plating comprising silver disposed on said substrate;
• and
• a coupling nut disposed around the mating ends of the first and second members and comprising an array of internal threads threadedly engaged with the threads of the first member and comprising an inwardly extending bearing flange releasably engaged with the other of the planar bearing surfaces of the thrust bearing, said coupling nut being formed from a metallic material less hard than the substrate of the thrust bearing, whereby threaded tightening of the coupling nut with the first member causes the flange of the coupling nut to slide against the thrust bearing and tightly urge the thrust bearing and the second member toward the first member for secure sealing engagement.