CONNECTING UNIT WITH CONNECTING PIPE Russian patent published in 2011 - IPC F16L47/12 

FIELD: machine building.

SUBSTANCE: connecting unit of metal fitting consists of internal conic mounting surface with polypropylene tube. It corresponds to a one mechanical connection tied with a polypropylene tube by contact welding. This connecting unit is used for a heating or water supply system in buildings and structures. The metal fitting is coupled with the propylene tube by means of the connecting pipe made out of propylene; the propylene tube is equipped with a sleeve nut. Conic external mounting surface facing the first end of the connecting pipe is made on this end; further, there is located a cylinder end section. The collar is made at a bigger base of conic external mounting surface. The connecting pipe is pressed with conic external mounting surface 8 to internal conic mounting surface of the fitting by means of the sleeve nut conjugated with its internal radial circular lug with surface of the collar on the side of the second end of the connecting pipe; also, the nut is screwed onto external screw surface of the fitting. The cylinder end section of the connecting pipe with a put on circular sealing element is positioned in a cylinder orifice of the fitting with a radial gap. Also, the circular sealing element is compressed between external surface of the cylinder end section of the connecting pipe and internal surface of the cylinder orifice of the fitting. It is additionally conjugated to a step of the connecting pipe conjugated in its turn to a lesser base of conic external mounting surface; this step is created with circular cross flat mounting surface.

EFFECT: increased reliability of connection.

7 cl, 2 dwg