A preassembly for a conduit fitting includes an annular fitting component having an interior wall extending along a central axis from an inboard end to an outboard end, a conduit gripping device disposed in the annular fitting component and comprising an outer radial surface at a back portion thereof, and a retaining device having an inboard first interlock portion that interlocks with the outer radial surface of the conduit gripping device, and an outboard second interlock portion axially spaced apart from the first interlock portion, the second interlock portion interlocking with the interior wall of the annular fitting component, such that the retaining device holds said annular fitting component and said conduit gripping device together as a discrete subassembly.

A ferrule for a conduit fitting includes an interior wall extending along a central axis through the ferrule between first and second end portions of the ferrule, so that the ferrule can be installed over a conduit end. The first end portion of the ferrule includes an axially outer first end driven surface disposed at a first angle between 70° and 90° with respect to the central axis, and an axially inner first end camming surface disposed at a second angle between 0° and 40° with respect to the central axis. The second end portion of the ferrule includes an axially outer second end driven surface disposed at a third angle substantially equal to the first angle, and an axially inner second end camming surface disposed at a fourth angle substantially equal to the second angle.

A device for making plumbing connections is provided. The device includes a first compression nut, a second compression nut, a sleeve fitting body between the first compression nut and the second compression nut, a first ferrule between the first compression nut and the sleeve fitting body, and a second ferrule between the sleeve fitting body and the second compression nut. The first compression nut has a first narrow portion and a first threaded portion, the first narrow portion having a first internal cavity with a first diameter. The second compression nut has a second narrow portion and a second threaded portion, the second narrow portion having a second internal cavity with a second diameter. The sleeve fitting body has a threaded portion that respectively correspond to the first and second threaded portions, and a first cavity portion having the first diameter, and a second cavity portion having the second diameter.

A device for making plumbing connections is provided. The device includes a first compression nut, a second compression nut, a sleeve fitting body between the first compression nut and the second compression nut, a first ferrule between the first compression nut and the sleeve fitting body, and a second ferrule between the sleeve fitting body and the second compression nut. The first compression nut has a first narrow portion and a first threaded portion, the first narrow portion having a first internal cavity with a first diameter. The second compression nut has a second narrow portion and a second threaded portion, the second narrow portion having a second internal cavity with a second diameter. The sleeve fitting body has a threaded portion that respectively correspond to the first and second threaded portions, and a first cavity portion having the first diameter, and a second cavity portion having the second diameter.

Compression fittings for pipes having a range of diameters, including a support body with a central section between end sections, the central section having a smaller diameter than the end sections, with a transition surface between the central section and each end section. A gasket fits over a pipe and engages one of the support body end section end surfaces. A fitting nut is movable axially over the support body to draw the support body and the gasket together in the axial direction and bias the gasket radially inward against the pipe. A grip ring encircles the pipe at one gasket end and has a surface engaging the fitting nut whereby the fitting nut biases the grip ring radially inwardly toward the pipe. An insert adapter has a hub with a radially extending flange may block the other gasket end to load the gasket between its axial ends.

A grip ring can include a ring body defining an inner surface facing radially inward, a first tooth, and a second tooth; each of the first tooth and the second tooth extending from the inner surface of the ring body, each of the first tooth and the second tooth defining a cylindrical end surface facing radially inward, a first side surface of each of the first tooth and the second tooth extending from the end surface of the respective tooth and towards the inner surface, and a second side surface of each of the first tooth and the second tooth extending from the end surface of the respective tooth and towards the inner surface; each of the first side surface and the second side surface of the respective tooth being angled in cross section with respect to the end surface.

A grip ring can include a ring body defining an inner surface facing radially inward, a first tooth, and a second tooth; each of the first tooth and the second tooth extending from the inner surface of the ring body, each of the first tooth and the second tooth defining a cylindrical end surface facing radially inward, a first side surface of each of the first tooth and the second tooth extending from the end surface of the respective tooth and towards the inner surface, and a second side surface of each of the first tooth and the second tooth extending from the end surface of the respective tooth and towards the inner surface; each of the first side surface and the second side surface of the respective tooth being angled in cross section with respect to the end surface.

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.

The invention relates to a coupling device for a tube having a Palladium-based membrane deposited thereon, for use in separation and purification of hydrogen in a hydrogen separator or reactor. The coupling device has an inlet for gas and configured to couple said tube to the inlet; a body part with a cylindrical opening for receiving the tube and for receiving gas flow to the inlet; a nut, the body part and the nut being configured such that the nut can be screwed onto the body part at the opening; a stack of at least two sealing rings. The body part, the nut and sealing rings are configured such that the tube extends through an axial end portion of the nut, the sealing rings into the opening such that, in use, the sealing rings are compressed axially as a result of screwing the nut onto the body part so that the sealing rings sealingly engage the tube.