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.

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.

A pipe joint made of synthetic resin includes: a joint body including a male screw portion on an outer circumferential portion; and a union nut including a female screw portion formed on an inner circumferential portion such that the female screw portion is tightened onto the male screw portion of the joint body. An outer circumferential surface of the joint body has a projection portion that is integrated therewith and projects radially outward. An inner circumferential surface of the union nut has a convex or concave engagement portion that is integrated therewith and engages with the projection portion when the union nut is tightened up to an appropriate position.

A pipe joint contains a body having a fluid passage in the interior thereof, a tightening cap screw-engaged with an end of the body for connecting a tube thereto, and an indicator ring interposed between a stopper of the body and an end of the tightening cap. The indicator ring is equipped with a flat section and an inclined section, which is inclined with respect to the flat section, and is formed with a smaller diameter than an outer circumferential surface of the tightening cap. When the tightening cap is screw-rotated to thereby connect the tube, as a result of the inclined section being pressed and deformed by movement of the tightening cap, the inclined section projects radially outward with respect to the outer circumferential surface of the tightening cap, whereby a tightened condition is visually confirmed by the outer edge of the indicator ring.

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 pipe joint structure has a joint body, a fixed ring and a union nut. A flared end of a tube has a conical surface and a tubular surface. The conical surface and tubular surface are connected to a tube connecting portion of the joint body. The union nut is fastened to a locking thread of the tube connecting portion. An interior recess portion of the union nut is coupled with a bulging surface of the fixed ring. The tube is compressed evenly and secured firmly on the joint body.

A joint is connected to a tube and includes a joint body, nut, and ring. The joint body has a tube coupling part and a main body thread part. The nut has a nut thread part and a constricted diameter part. The ring is arranged in a space radially inward of the nut thread part. The ring abuts an abutted part of the nut. The ring has a Young's modulus greater than the tube. The ring has a curved surface part at least at a radially inward portion of the ring axially on the joint body side, the curved surface part bulging radially inward of the ring and axially toward the joint body side. A maximum thickness of the ring in a radial direction is defined as 2r, an axial length of the curved surface part of the ring is defined as h, and α=h/r being 0.5 to 1.2.

A fitting assembly may seal a wire within a tube to inhibit ingress of fluid outside the tube into the tube and into contact with the wire. The fitting assembly may optionally include a body and a nut, with a part of the nut received within the body. The nut may be threadedly connected to the body, such that threading and/or unthreading the nut translates the part of the nut within the body. Optionally, the nut may include a ring extension that is received within a ring cavity of the body, and an interfacing between the ring extension and the ring cavity may create a seal to inhibit leaking of the fluid past the seal. A method of sealing a wire within a tube may comprise positioning a tube with a wire therein within such a fitting assembly.

A pipe fitting includes a fitting body defining an inner surface, an outer surface, a first fitting end, and a second fitting end, the inner surface defining a channel extending from the first fitting end to the second fitting end, a portion of the inner surface defining a tapered region tapering towards the first fitting end; and an engagement assembly comprising a metal grip ring received in the channel, the metal grip ring defining a substantially frustoconical ring body, the ring body defining a diameter that tapers from a first lateral end of the ring body to a second lateral end of the ring body, the engagement assembly configured to slide along the tapered region.

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.