Transition pipe fitting

Claim 1

A transition pipe fitting assembly for interconnecting a pliant gas conduit to a gas meter riser having gas flowing therethrough in a downstream direction, wherein said assembly comprises: a first half of a standard pipe union serving as a coupling sleeve having an annular threaded shoulder portion extending radially outwardly therefrom, a threaded bore formed therein for threaded engagement with a downstream end portion of said gas meter riser, a recess formed in a downstream surface portion of said coupling sleeve concentric with said threaded bore so as to form a passage through said coupling sleeve, and an annular groove formed in said downstream surface portion of said coupling sleeve radially outwardly from and coaxial with said recess; a compression seal disposed within said recess and having an axial channel formed therethrough; an O-ring seal disposed within said annular groove; a rigid pipe having a downstream end portion thereof inserted within said axial channel formed through said compression seal; a flat washer concentrically secured to said downstream end portion of said rigid pipe for resisting withdrawal of said rigid pipe from said axial channel formed through said compression seal such that said flat washer abuts a downstream surface portion of said compression seal; a second half of said standard pipe union operatively associated with said coupling sleeve; and a coupling nut having threads formed therein and threadedly engaged with said annular threaded shoulder portion of said coupling sleeve to force said second half of said standard pipe union against said flat washer, against said O-ring seal and against said downstream surface portion of said coupling sleeve so as to form a first gas tight seal via compression of said O-ring and to form a second gas tight seal radially inwardly from said first gas tight seal via compression of said compression seal.