A pipe-fitting device capable of easily connecting pipes having different diameters includes a fitting body and a pair of fixing nuts. The fitting body includes a first channel portion having a first inner diameter formed in a first inner side of the fitting body, a second channel portion having a second inner diameter formed in a second inner side of the fitting body, the second inner diameter being smaller than the first inner diameter such that a step is formed inside the fitting body at the boundary between the first channel portion and the second channel portion. Each fixing nut is rotatably coupled to a corresponding open end of the fitting body and configured to fix the corresponding one of the first pipe and the second pipe through rotational tightening.

Apparatus for detecting an electrical insult to a gas tubing system and dissipating the energy from such insult. The system includes tubing and an injury mitigator. The tubing includes a conduit, an insulating layer, a conductive layer, and a jacket. The conduit is connected to earth ground. The conductive layer is electrically insulated from the conduit by the insulating layer. The mitigator includes an insult event detection circuit and an energy dissipation circuit, both electrically connected between the conductive layer of the tubing and ground. Insult indication is provided by a fusible link. Energy dissipation is provided by the fuse, a transient voltage suppression (TVS) device, and/or a spark gap. The TVS device has a setpoint voltage less than the breakdown voltage of the spark gap, ensuring that the TVS device actuates before the spark gap conducts. In one embodiment, at least one terminating connector

One aspect of the invention provides an elastomeric bushing including: a plurality of rigid members defining one or more internal annular ribs and one or more elastic members. The rigid members include: a first internal annular rib adapted and configured to engage a corrugation valley of corrugated tubing; and one or more trailing lips adapted and configured to extend through a central opening of a nut and engage said nut, thereby preventing axial movement of the bushing when a corrugated tubing is advancing through the bushing. The one or more elastic members are adapted and configured to: hold the plurality of rigid members in a substantially annular configuration; allow the plurality of rigid members to expand to allow a corrugation peak to pass under the first internal rib; and hold the plurality of rigid members against the corrugated tubing so that the first internal rib lies within a corrugation valley.

Apparatus for detecting an electrical insult to a gas tubing system and dissipating the energy from such insult. The system includes tubing, at least one terminating connector, and an injury mitigator. The tubing includes a conduit, an insulating layer, a conductive layer, and a jacket. The conduit is connected to earth ground. The conductive layer is electrically insulated from the conduit by the insulating layer. The mitigator includes an insult event detection circuit and an energy dissipation circuit, both electrically connected between the conductive layer of the tubing and ground. Insult indication is provided by a fusible link. Energy dissipation is provided by the fuse, a transient voltage suppression (TVS) device, and/or a spark gap. The TVS device has a setpoint voltage less than the breakdown voltage of the spark gap, ensuring that the TVS device actuates before the spark gap conducts.

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.

One aspect of the invention provides a method of forming an energy-dissipative tube. In one embodiment, the method includes: extruding a resin layer over an outer surface of corrugated stainless steel tubing and impregnating the resin layer with metal particles. In another embodiment, the method includes: extruding a resin layer comprising a fire retardant over an outer surface of corrugated stainless steel tubing and impregnating the resin layer with metal particles. In another embodiment, the method includes: extruding a resin layer comprising between about 20% to 60% magnesium hydroxide, aluminum trihydrate, or halogenated fire retardants by weight over an outer surface of corrugated stainless steel tubing and impregnating the resin layer with metal particles selected from the group consisting of: copper, aluminum, gold, silver, and nickel.

One aspect of the invention provides a bushing including: a plurality of rigid members defining one or more internal ribs including a first internal rib adapted and configured to engage a corrugation valley of corrugated tubing; and one or more elastic members adapted and configured to: hold the plurality of rigid members in substantially annular configuration; allow the plurality of rigid members to expand to allow a corrugation peak to pass under the first internal rib; and hold the plurality of rigid members against the corrugated tubing so that the first internal rib lies within a corrugation valley. Another aspect of the invention provides a fitting including: a body member defining a sleeve portion; and a bushing as described herein received within the sleeve portion of the body member.

A pipe joint, made of synthetic resin, including: an inner ring; a joint body having an annular sealing groove and a male screw portion formed on an outer circumference; a union nut having a female screw portion formed on an inner circumference to be tightened onto the male screw portion of the joint body, such that a first opposing surface is formed in the joint body to be perpendicular to an axial direction, and a second opposing surface is formed in the union nut to oppose the first opposing surface. An engagement projection is provided in one of the first opposing surface and the second opposing surface. An engagement recess is provided in the other of the first opposing surface and the second opposing surface such that the engagement projection engages with the engagement recess when the union nut has been tightened up to an appropriate position.

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 pipe joint made of synthetic resin comprises a first opposing surface formed in a joint body perpendicular to the axial direction, and a second opposing surface formed in a union nut that opposes the first opposing surface. An engagement projection is provided in the second opposing surface that projects toward the first opposing surface. An engagement recess is provided in the first opposing surface such that the engagement projection engages with the engagement recess when the union nut has been tightened up to an appropriate position.