A fitting for a fluid line that will contain pressurized fluid can include first and second fitting elements with respective sealing surfaces and an indicator element for indicating when a fluid seal has been formed. A fitting for a fluid line that will contain pressurized fluid can include first and second fitting elements with a sealing structure secured in one of the first and second fitting elements, wherein the sealing structure is axially resiliently compressible, one example of which includes a bellows element.

A fitting for a fluid line that will contain pressurized fluid can include first and second fitting elements with respective sealing surfaces and an indicator element for indicating when a fluid seal has been formed. A fitting for a fluid line that will contain pressurized fluid can include first and second fitting elements with a sealing structure secured in one of the first and second fitting elements, wherein the sealing structure is axially resiliently compressible, one example of which includes a bellows element.

Provided is joint unit having a resin tube, a joint structure, and a nut, the joint structure has a guide part that guides the outer circumferential face of the resin tube, a protrusion that forms an insertion groove between the guide part and the protrusion, and a fixing part that fixes the resin tube inserted in the insertion groove, the tip of the protrusion is located closer to a main body than the tip of the guide part, the nut has a recessed part having an inner diameter greater than a first outer diameter of the guide part and smaller than a second outer diameter of the fixing part, and the tip of the fixing part in contact with the recessed part bites into the outer circumferential face of the resin tube in a state where the nut is fastened to the joint structure.

A pipe coupling segment includes an arcuate body portion defining a first end, a second end opposite the first end, a first axial side, and a second axial side opposite the first axial side; a hook extending from the first end of the arcuate body portion, wherein the hook defines a shank portion and a bend portion, the shank portion extending in a substantially radially outward direction from the arcuate body portion and the bend portion extending in a substantially axial direction from the shank portion, the bend portion defining an upper engagement surface, the upper engagement surface defining a sloped portion angled rearwardly towards the shank portion; and a fastener lug extending from the second end of the arcuate body portion.

A pipe coupling segment includes an arcuate body portion defining a first end, a second end opposite the first end, a first axial side, and a second axial side opposite the first axial side; a hook extending from the first end of the arcuate body portion, wherein the hook defines a shank portion and a bend portion, the shank portion extending in a substantially radially outward direction from the arcuate body portion and the bend portion extending in a substantially axial direction from the shank portion, the bend portion defining an upper engagement surface, the upper engagement surface defining a sloped portion angled rearwardly towards the shank portion; and a fastener lug extending from the second end of the arcuate body portion.

A coupling segment can comprise an arcuate central portion defining a first end, a second end, a first axial side, and a second axial side; a first end portion defining a shank and a bend, the shank extending from the first end of the arcuate central portion proximate the first axial side, the bend extending from the shank towards the second axial side, the bend defining a proximal end coupled to the shank and a distal end distal from the shank, the bend defining an engagement surface and a bottom surface opposite the engagement surface, the bottom surface lying in a plane, wherein the bottom surface faces away from the coupling segment such that the plane does not intersect the coupling segment; and a second end portion extending from the second end of the arcuate central portion, the second end portion defining an opening.

A dielectric fitting includes a nut having inner threads and an axial compression surface, and a hole having a first diameter. A mating component includes outer threads that engage with the inner threads including a second axial compression surface. A first fitting includes a circumferential flange captured between the first axial compression surface and the second axial compression surface, the first fitting having a first wall that extends axially and passes through the first hole and includes first fitting threads. A second fitting includes second fitting threads that engage with the first fitting threads, the second fitting having a second wall and a bulge portion that radially projects to a second diameter and includes an O-ring. The nut and the mating component are dielectrically isolated from the first fitting and the second fitting, and the second diameter is larger than the first diameter.

A hooked pipe coupling includes a first pipe coupling segment comprising a first arcuate body portion defining a first end and a second end opposite the first end, a first hook extending from the first end, and a first fastener lug extending from the second end, the first arcuate body portion defining a first sloped ledge surface; and a second pipe coupling segment comprising a second arcuate body portion defining a third end and a fourth end opposite the third end, a second hook extending from the third end, and a second fastener lug extending from the fourth end, the second arcuate body portion defining a second sloped ledge surface; wherein the first sloped ledge surface presses against the second sloped ledge surface in a tightened configuration of the hooked pipe coupling to prevent axial movement of the first pipe coupling segment relative to the second pipe coupling segment.

A dielectric fitting includes a nut having inner threads and an axial compression surface, and a hole having a first diameter. A mating component includes outer threads that engage with the inner threads including a second axial compression surface. A first fitting includes a circumferential flange captured between the first axial compression surface and the second axial compression surface, the first fitting having a first wall that extends axially and passes through the first hole and includes first fitting threads. A second fitting includes second fitting threads that engage with the first fitting threads, the second fitting having a second wall and a bulge portion that radially projects to a second diameter and includes an O-ring. The nut and the mating component are dielectrically isolated from the first fitting and the second fitting, and the second diameter is larger than the first diameter.

Example aspects of a coupling segment and a method for assembly a pipe coupling are disclosed. The coupling segment can comprise an arcuate central portion defining a first end, a second end, a first axial side, and a second axial side; a first end portion defining a shank and a bend, the shank extending from the first end of the arcuate central portion proximate the first axial side, the bend extending from the shank towards the second axial side, the bend defining a proximal end coupled to the shank and a distal end distal from the shank, the bend defining an engagement surface and a bottom surface opposite the engagement surface, the bottom surface lying in a plane, wherein the bottom surface faces away from the coupling segment such that the plane does not intersect the coupling segment; and a second end portion extending from the second end of the arcuate central portion, the second end portion defining an opening.