Coupling

A plumbing fitting for coupling a water supply line to a second plumbing fitting comprising:

• a polymeric tailpiece having a first end for coupling to a supply line and an opposite end with a radially outwardly extending annular flange having an annular face surface;
• a circular recess formed in said face surface for receiving a seal;
• a seal positioned in said circular recess;
• and
• a nut positioned over said tailpiece and having a radially inwardly extending annular rim engaging a side of said flange opposite said face surface, said nut made of a polymeric material having internal threads, said nut further including an integral metal insert extending in concentric spaced relationship to said threads of said nut and including an end which is threaded and which is coaxial with said threads of said nut and located on said nut remote from said rim such that as said fitting is secured to a second plumbing fitting, said threads of said metal insert engage said second plumbing fitting first, wherein said threads of said metal insert are axially dimensioned to allow said polymeric threads of said nut to engage a second plumbing fitting as the fitting is secured and said seal engages the second plumbing fitting to form a watertight connection.

A plumbing fitting for coupling a water supply line to a water meter comprising:

• a water meter having a threaded water input end;
• a polymeric tailpiece having a first end for coupling to a supply line and an opposite end with a radially outwardly extending annular flange having an annular face surface;
• a circular recess formed in said face surface for receiving a seal;
• a seal positioned in said circular recess;
• and
• a nut positioned over said tailpiece and having a radially inwardly extending annular rim engaging a side of said flange opposite said face surface, said nut made of a polymeric material having internal threads, said nut further including an integral metal insert extending in concentric spaced relationship to said threads of said nut, said insert including an end which is threaded and which is coaxial with said threads of said nut and located in said nut such that said end of said insert is substantially flush with said nut, such that, as said fitting is secured to said water meter, said threads of said metal insert engage said threaded input end first, wherein said threads of said metal insert are axially dimensioned to allow said polymeric threads of said nut to engage said threaded input end as the fitting is secured and said seal engages said water meter to form a watertight connection.