Abstract: An anti-rotational push to connect fitting includes a housing defining an internal cavity, the internal cavity having, at least in part, a non-circular shape. The housing has a conduit receiving region having an inwardly oriented wall. A seal is positioned in the housing adjacent to the conduit receiving region. A grip ring support is positioned in the housing adjacent to the seal. The grip ring support has a transverse flange having an inner peripheral edge and an outer peripheral edge and a longitudinal wall extending from the flange spaced from the inner and outer peripheral edges to define gaps between the longitudinal wall and a wall of the housing and inwardly of the longitudinal wall. A grip ring is positioned adjacent to the grip ring support and is seated on an end of the wall. The grip ring has a non-circular shape configured to cooperate with the housing internal cavity and the grip ring support.

Abstract: A crimp fitting comprises a metal tube wall that forms both a cylindrical tube portion and an adjacent annular O-ring channel portion. The tube wall has a first wall thickness along the cylindrical tube portion and a second wall thickness along at least part of the O-ring channel portion. The second wall thickness is less than the first wall thickness. The cylindrical tube portion and O-ring channel are configured and adapted to encircle a cylindrical end portion of a tube when such end portion of the tube is inserted into the fitting.

Abstract: A crimp fitting comprises a metal tube wall that forms both a cylindrical tube portion and an adjacent annular O-ring channel portion. The tube wall has a first wall thickness along the cylindrical tube portion and a second wall thickness along at least part of the O-ring channel portion. The second wall thickness is less than the first wall thickness. The cylindrical tube portion and O-ring channel are configured and adapted to encircle a cylindrical end portion of a tube when such end portion of the tube is inserted into the fitting.

Abstract: Flattened fluid conduits for use in heat exchangers and other systems, and associated methods of manufacture and use are disclosed herein. In one embodiment, the fluid conduit for use in heat exchangers can be manufactured by inserting two or more inner tubes into a circular or at least partially circular barrier tube and at least partially flattening at least some length of the assembly. The heat exchanger conduit can include one or more void spaces within the barrier tube and adjacent to the inner tubes which serve to contain any leaks in the inner tubes and vent any leaks to the atmosphere.

Abstract: Fluid conduits for plumbing and other uses having integral end fittings are disclosed herein. A method of forming a fluid conduit in accordance with an embodiment of the disclosure includes providing a copper tube having a first inner diameter and a first wall thickness, and heat treating an end portion of the copper tube to a predetermined hardness. The method can further include increasing the wall thickness of the end portion from the first wall thickness to a second wall thickness, and increasing the inner diameter of the end portion from the first inner diameter to a second inner diameter. The method further includes forming a circular groove in an interior surface of the end portion and positioning a seal in the circular groove.