A double containment fitting for connection to a double containment tubing system with an outer, secondary containment tubing surrounding an inner, primary tubing. The fitting includes a fitting body defining a central passageway, the fitting body having a center portion disposed between opposed first and second body ports. The fitting body is configured to receive the tubing system into the first body port. The central passageway has a diameter in the first port selected to allow the secondary tubing into the first body port. A connection system mechanically secures the secondary tubing to the first body port.

A high torque polymer fittings useful in fluid handling systems. The fittings are especially useful for fluid handling fittings having diameters of one inch or greater. Various embodiments of the fittings disclosed accommodate specialized wrenches for securing the fittings, the wrenches being used to tighten the fittings to a desired torque.

A structure of a resin-made pipe joint includes a sleeve which is press-insertable from one axial side into one longitudinal end portion of a flexible tube to flare the one longitudinal end portion to hold the flared state, a joint body which is couplable to the sleeve, and a union nut which is fastenable to the joint body to hold a state where the sleeve press-inserted into the one longitudinal end portion is coupled to the joint body. The sleeve has a taper-like first outer circumferential surface, a second outer circumferential surface having an outer diameter that is smaller than a maximum outer diameter of the first outer circumferential surface, and an annular step portion which is an annular step portion that is disposed between the first outer circumferential surface and the second outer circumferential surface and comprises an edge portion on a side of the first outer circumferential surface.

Disclosed is a structure for preventing a leak at a synthetic resin tube joint, which includes a synthetic resin tube including a tapered portion at an end portion; a ferrule inserted into the end portion of the synthetic resin tube and including a tapered portion corresponding to the tapered portion of the synthetic resin tube; a fitting which accommodates the synthetic resin tube and the ferrule, and includes a tapered portion corresponding to the tapered portion of the synthetic resin tube and a protrusion formed on the tapered portion of the fitting, and a nut which engages with the fitting.

A sleeve, a cylindrical member for connecting a tube to a tubular body of a fitting, includes a first peripheral wall end portion facing a peripheral wall end portion of the tubular body, and a second peripheral wall end portion pressed into an open end of the tube. The first peripheral wall end portion includes either an annular protrusion or groove. The annular protrusion is pressed into an annular groove in the peripheral wall end portion of the tubular body. The annular groove allows an annular protrusion axially projecting from the peripheral wall end portion of the tubular body to be pressed thereinto. The second peripheral wall end portion includes a bulge portion to expand the diameter of the open end of the tube. An outer periphery of the first peripheral wall end portion includes a flange to axially face the peripheral wall end portion of the tubular body.

A pipe joint includes: an inner ring having a bulge portion to be press-fitted into an end portion of the tube; a joint body having an inner circumference into which an end portion of the inner ring is to be press-fitted, and having an external thread portion on an outer circumference thereof; and a union nut having an internal thread portion to be tightened to the external thread portion, and configured to press the end portion of the tube when the internal thread portion is tightened to the external thread portion. The bulge portion has a tapered portion configured to generate a surface pressure between the tube and the tapered portion by pressing by the union nut. An outer circumferential surface of the tapered portion has a concave surface portion formed in a concave surface shape in an axial cross-sectional view.

A double containment fitting for connection to a double containment tubing system with an outer, secondary containment tubing surrounding an inner, primary tubing. The fitting includes a fitting body defining a central passageway, the fitting body having a center portion disposed between opposed first and second body ports. The fitting body is configured to receive the tubing system into the first body port. The central passageway has a diameter in the first port selected to allow the secondary tubing into the first body port. A connection system mechanically secures the secondary tubing to the first body port.

A fluid circuit includes a plurality of tubing segments and a plurality of operative components. Each tubing segment includes i) a non-conductive polymer portion defining a fluid passageway and ii) one or more interior conductive fluoropolymer stripes extending axially to the ends of each of the respective tubing segments. Each operative component includes a conductive fluoropolymer that extends between a plurality of tubing connector fittings forming a part of the fluid circuit, wherein each of the tubing connector fittings conductively connect the respective conductor of the operative component to the interior conductive fluoropolymer stripes of the tubing segment to provide a path to ground that extends through each operative component and each tubing segment.

A resin tube fitting prevents backwaters between its body and inner ring. The fitting includes a body, an inner ring, and a union nut. The body has main, outer, and inner sleeves, and a groove. The inner ring has a cylinder, an insert, and outer and inner protrusions. The union nut has a body and a pressing member. The inner sleeve has a through hole serving as a channel. The inner protrusion extends from the cylinder to an axial direction to contact the inner sleeve. The inner protrusion has a through hole serving as another channel connected with the inner sleeve's channel. The tip of the inner protrusion has an inner diameter not less than the minimum inner diameter of the inner sleeve. An inner peripheral surface is located at the inner periphery of the inner protrusion and causes it to reduce in inner diameter toward another axial direction.

A structure of a resin-made pipe joint includes a joint body having a cylindrical shape, a sleeve having a cylindrical press-inserting portion which is press-insertable into the joint body and a cylindrical coupling portion which is press-insertable into a tube, and a fastening member for fixing the tube which is in a state where the coupling portion is press-inserted, to the joint body through the sleeve. The sleeve contains a sealing surface in an outer circumferential surface of the press-inserting portion, the sealing surface being closely contactable with an inner circumferential surface of the joint body, and comprises a non-contacting surface between the press-inserting portion and the coupling portion, the non-contacting surface forming a space with respect to the inner circumferential surface of the joint body, when the sealing surface is closely contacted with the inner circumferential surface of the joint body.