The present application discloses methods and apparatus for installing fitting components, such as a conduit gripping device, on a conduit to form an assembly. The assembly is joinable with at least one other fitting component to form a fitting. The present application also discloses methods and apparatus for evaluating characteristics of components of a mechanically attached connection. Characteristics that may be evaluated include, but are not limited to, the position of a conduit gripping device on a conduit, an amount of axial compression or stroke of the conduit gripping device, an amount of clamping force applied to the conduit gripping device as the conduit gripping device is compressed, and an amount of torque applied to members that compresses the conduit gripping device.

A fitting for a tube or pipe capable of functioning a high pressures having a first fitting component adapted to receive the conduit end; a conduit gripping device such as a ferrule or ferrules and a second fitting component that can be joined to the first fitting component to cause the conduit gripping device to grip the conduit and seal when assembled. In one aspect of the invention, the first fitting component is constructed from a material that is softer than the material used to construct the second fitting component. An additional aspect of the invention include a retaining portion on the second fitting component that constrains the tube gripping device against pressure. The retaining portion can also be configured to retain the tube gripping device to the second fitting component prior to installation and in a finger-tight condition. A further aspect of the invention includes a first fitting component in which an exterior portion of the component is work hardened radially outward from the tube gripping device. The fitting may optionally be provided with a structure to effect the pull-up by torque functionality.

A pipe cap assembly for a normally-sealed system includes a pipe cap having a base portion. The pipe cap includes a connector portion extending from the base portion. A fluid passage extends through both the base portion and connector portion. A transition cap may be releasably coupled to the connector portion for sealing the fluid passage during normal operation. A transition fitting provides periodic access to the sealed system and includes an access port at one end, and a tubular port and fastener at the other end. The tubular port and fastener releasably couple to the connector portion of the pipe cap to provide access. A drain hose, vent hose, or the like, may be easily coupled to the access port of the transition fitting. A test instrument may be coupled either to the access port or directly to the connector portion.

A fitting includes a first and second threaded fitting component and a conduit gripping device receivable within the first threaded fitting component. A stroke resisting member is integral with the first threaded fitting component and includes a web having a first radial thickness and extending axially inward from the first threaded fitting component to a distal ring portion having a second radial thickness greater than the first radial thickness. A radially extending bearing surface of the distal ring portion axially engages a radially extending portion of the second fitting component when the first and second fitting components are joined together to the first relative axial position. The stroke resisting member resists additional axial stroke of the first and second fitting components, such that a tightening torque beyond the first relative axial position is increased by the axial engagement.

Apparatus and method for mechanically attached connections of conduits may include a conduit gripping member, a drive member, and a seal member, the drive member causing axial movement of the conduit gripping member to indent into an outer surface of the conduit when the assembly is pulled-up, the drive member causing the seal member to form a zero clearance seal at a location that is axially spaced from the conduit gripping member. The zero clearance seal may comprise a face seal arrangement including a gasket, and the conduit gripping member may be a ferrule, ring or other device that can grip and optionally seal against the conduit outer surface. The assembly may include a sensing function for detecting or sensing a characteristic or condition of an assembly component or the fluid or both. In one embodiment, a body coupling member has a two piece construction of a main body and a conduit socket insert. A flared fitting embodiment is also provided. Sensing functions are also incorporated into fittings other than just zero clearance fittings.

The disclosure presents exemplary embodiments of a cartridge nut concept for conduit fittings. The cartridge nut concept may include the feature of loosely retaining one or more conduit gripping devices with a fitting component such as a male or female threaded nut. The cartridge nut concept may be realized using one or more geometry or shape features or characteristics of one or more conduit gripping devices. Still further, the cartridge nut concept may be realized in combination with a ferrule cartridge concept.

A pipe cap assembly for a normally-sealed system includes a pipe cap having a base portion including two opposing, substantially parallel flat surfaces. The pipe cap includes a connector portion extending from the base portion. A fluid passage extends through both the base portion and connector portion. A transition cap may be releasably coupled to the connector portion for sealing the fluid passage during normal operation. A transition fitting provides periodic access to the sealed system and includes an access port at one end, and a tubular port and fastener at the other end. The tubular port and fastener releasably couple to the connector portion of the pipe cap to provide access. A drain hose, vent hose, or the like, may be easily coupled to the access port of the transition fitting. A test instrument may be coupled either to the access port or directly to the connector portion.

A preassembly for a conduit fitting includes an annular fitting component and at least a first conduit gripping device. The annular fitting component has an interior wall including an inboard surface having a first diameter, an outboard surface having a second diameter, and an intermediate surface recessed from the inboard surface by an outward facing inboard radial wall and recessed from the outboard surface by an inward facing outboard radial wall. The first conduit gripping device is retained within the annular fitting component and includes a body portion and an annular ring portion having an inner radial portion secured to a rear surface of the body portion, and a flange portion extending radially outward of the inner radial portion to define a projection extending radially outward of an outer circumferential surface of the first conduit gripping device, with an end portion of the projection being axially captured between the inboard radial wall and the outboard radial wall.

A fitting includes a first and second threaded fitting component and a conduit gripping device receivable within the first threaded fitting component. A stroke resisting member is integral with the first threaded fitting component and includes a web having a first radial thickness and extending axially inward from the first threaded fitting component to a distal ring portion having a second radial thickness greater than the first radial thickness. A radially extending bearing surface of the distal ring portion axially engages a radially extending portion of the second fitting component when the first and second fitting components are joined together to the first relative axial position. The stroke resisting member resists additional axial stroke of the first and second fitting components, such that a tightening torque beyond the first relative axial position is increased by the axial engagement.

A fitting assembly having a longitudinal axis including a fitting body having a seat, a threaded drive nut, a tube, a first (rear) ferrule and a second (front) ferrule receivable over the tube, the first (rear) ferrule having a first driven end and a first driving end and defining a first (rear) ferrule length (FFL) therebetween, the second (front) ferrule having a second driven end and a second driving end and defining a second (front) ferrule length (SFL) therebetween, and a seal depth (SD) of the tube defined by a distance between the seat of the fitting body and the second driving end. A surface of the second driven end of the second (front) ferrule is a diametrical surface having a diameter (D.sub.SF). At least one of the following apply:

SFL/SD0.9;

2.7SFL/D.sub.SF2.2; and

SFL/FFL4.0.