A coupling for joining pipe elements has cast segments attached end to end surrounding a central space. The segments define a channel that receives a gasket. Side surfaces within the channel have angularly oriented capture surfaces which are engaged by bulbous rims on the gasket which prevent the gasket from being dislodged from the channel when at least one pipe element is inserted into the central space. Side surfaces may also have support surfaces between the capture surfaces. The gasket supports the segments in a preassembled state wherein the segments are in spaced relation sufficient to permit insertion of one or more pipe elements while the segments are attached end to end.

A pipe coupling includes a first coupling segment defining opposed ends, one end of the first coupling segment defining a first pivotal mount, and another end of the first coupling segment defining a second pivotal mount; a second coupling segment defining opposed ends, a proximal end of the second coupling segment configured to pivotally connect to the first pivotal mount, and a distal end of the second coupling segment configured to receive a fastener; and a third coupling segment defining opposed ends, a proximal end of the third coupling segment configured to pivotally connect to the second pivotal mount, and a distal end of the third coupling segment configured to receive the fastener.

A pipe coupling includes a first coupling segment defining opposed ends, one end of the first coupling segment defining a first pivotal mount, and another end of the first coupling segment defining a second pivotal mount; a second coupling segment defining opposed ends, a proximal end of the second coupling segment configured to pivotally connect to the first pivotal mount, and a distal end of the second coupling segment configured to receive a fastener; and a third coupling segment defining opposed ends, a proximal end of the third coupling segment configured to pivotally connect to the second pivotal mount, and a distal end of the third coupling segment configured to receive the fastener.

A ventilation apparatus includes a plurality of tubular conduit sections, each conduit section including a first semi-tubular section and a second semi-tubular section, each semi-tubular section having a cross-sectional profile generally in the form of an open semi-circular annular element, when viewed along a longitudinal axis. Each tubular conduit includes a first engagement formation located at an end of the tubular conduit, and a second engagement formation located at an opposing end of the tubular conduit.

A grooved-ended resilient expansion joint is disclosed. The expansion joint has a resilient expansion member with a central resilient portion and two resilient axially disposed cylindrical ends. Each cylindrical end has a radially outwardly raised distal cylindrical gasket portion with at least one inside shoulder having an inner diameter sized substantially the same as an outer diameter of a pipe to be joined. A pair of pre-assembled pipe couplings are provided for joining the expansion joint to a pair groove-ended pipe segments without disassembling the coupling.

A valve and coupling for joining pipe elements has a valve body captured in a central space defined by a plurality of coupling segments attached to one another end to end. The inner surface of the valve body defines a bore. A liner on the inner surface surrounds the bore and forms a seal with a valve closing member. Circumferentially arranged projections on the segments engage and center the valve body within the central space. The liner has lobes that extend axially in opposite directions. The lobes are compressed between the segments and the pipe elements to form a fluid tight seal when connection members are tightened to draw the segments toward the central space and into engagement with the pipe elements.

A preassembled coupling for joining pipe elements has segments surrounding a central space with cusps which engage lobes of a seal to maintain the segments in spaced apart relation in a preassembled state. While the coupling is in the preassembled state the pipe elements may be inserted into the central space without disassembling the coupling, and portions of the seal adjacent to attachment members on the segments seat within a channel defined by the segments between the cusps, while portions of the seal between the attachment members are further from a back surface of the channel.

A preassembled coupling for joining pipe elements has segments surrounding a central space with cusps which engage lobes of a seal to maintain the segments in spaced apart relation in a preassembled state. While the coupling is in the preassembled state the pipe elements may be inserted into the central space without disassembling the coupling, and portions of the seal adjacent to attachment members on the segments seat within a channel defined by the segments between the cusps, while portions of the seal between the attachment members are further from a back surface of the channel.

A pipe fitting for plain end pipe is formed of housing portions defining receptacles for receiving pipe elements. The receptacles are coaxial with respective axes oriented angularly with respect to each other. Each receptacle has a channel that faces a respective axis with floors at different radii of curvature. Retainers are received within the channels. The retainers have teeth and one or more offset tabs that cooperate with the channels to prevent improper assembly of the fitting. Ring seals are received within channels positioned adjacent to the receptacles. The ring seals cooperate with the retainers to hold the segments in spaced relation sufficient to insert pipe elements into the receptacles when the fitting is pre-assembled. Apertures are provided in the receptacles to permit visual determination of the presence of the retainers post assembly.

A pipe coupling for plain end pipe is formed of segments joined end to end surrounding a central space. The segments are connected end to end by lugs on each segment with fasteners extending between them. Each segment has channels on opposite sides that face the central space with floors at different radii. Retainers are received within the channels. The retainers have teeth and one or more offset tabs that cooperate with the channels to prevent improper assembly. A ring seal is received within a channel positioned in each segment between the retainer channels.