Block fitting and seal structure

A block fitting for an air conditioning system comprising:

• a male block portion including a first aperture receiving a tube end therein, said male block portion including an annular shoulder surrounding the first aperture of said male block portion, the annular shoulder including an axially extending lip formed at a first end thereof;
• a female block portion including a first aperture receiving a tube end therein, said female block portion including an annular collar surrounding the first aperture of said female block portion and cooperating with the annular shoulder formed by said male block portion, the first aperture of said male block portion and the first aperture of said female block portion being substantially concentrically aligned;
• a seal structure disposed radially inward from the axially extending lip of said male block portion and between said male block portion and said female block portion, the seal structure including a first seal portion produced from a deformable metal or plastic material and having a free edge, said first seal portion surrounding the first aperture of said male block portion and the first aperture of said female block portion, and a second seal portion produced from an elastomer disposed on the free edge of said first seal portion;
• and
• a fastener sealingly engaging said male block portion and said female block portion, said fastener causing said male block portion and said female block portion to deform the first seal portion and provide a primary seal between said male block portion and said female block portion, and said fastener causing said male block portion and said female block portion to cooperate with the second seal portion and provide a secondary seal between said male block portion and said female block portion, wherein the primary seal and the secondary seal militate against a leakage of a fluid from the block fitting.