Abstract: A pipe coupling may include a body that is tubular and formed from a polymer. The body may include a main bore with a main axis and at least first and second female receptacles on each end of the main bore. Each receptacle may be configured to receive a male end of a pipe. A first brace may be coupled to and extend between, for example, a first female receptacle and a third female receptacle. A second brace may be coupled to extend between, for example, a second female receptacle and the third female receptacle. The pipe coupling can be a single, integral, injection molded monolithic structure.

Abstract: A pipe may include a pipe body having an axis, an axial bore and a pipe body outer diameter. A male end may be formed on the pipe body. The male end can have an outer diameter consistent with the pipe body outer diameter, and an axial end face. A female end may be formed as an integral bell on the pipe body opposite the male end. The female end may have an inner diameter that is larger than the outer diameter of the male end, a seal recess on an interior thereof, and an interior feature in the interior of the female end that is complementary to the axial end face of the male end. The female end of a first pipe may be configured to receive the male end of a second pipe, such that the interior feature of the first pipe engages and restrains the axial end face of the second pipe. A coupling may be used to join two of the pipes.

Abstract: A polymeric riser cap member includes a central tubular section defining a generally cylindrical bore for receiving a sprinkler riser, the central tubular section having open top and bottom ends, and an annular skirt coaxial with the central tubular section and having an inner diameter larger than an inner diameter of the central tubular section. The annular skirt has an inner surface having internal threads threadably connectable with the externally threaded surface of a tubular riser adapter member of a tubular coupler. The bottom end of the central tubular section has an annular projection disposed opposite and spaced from a portion of the annular skirt. The riser cap member includes an annular recess adapted to receive a seal located in a wall extending laterally between the annular skirt and the annular projection.

Abstract: A pipe has a tubular body with a male end and a female end. The male end has an external surface with a first engagement groove. The female end has an internal surface with a second engagement groove, and an aperture extending from an outer surface of the tubular body to the second engagement groove. The female end receives the male end of another pipe such that the first engagement groove of the male end axially aligns with the second engagement groove of the female end to establish a spline engagement groove having a groove length, LG. A flexible spline is located in the spline engagement groove to lock the pipes together and establish a pipe assembly. The flexible spline has a spline length, LS, and LS?LG.

Abstract: A pipe has a tubular body with a male end and a female end. The male end has an external surface with a first engagement groove. The female end has an internal surface with a second engagement groove, and an aperture extending from an outer surface of the tubular body to the second engagement groove. The female end receives the male end of another pipe such that the first engagement groove of the male end axially aligns with the second engagement groove of the female end to establish a spline engagement groove having a groove length, LG. A flexible spline is located in the spline engagement groove to lock the pipes together and establish a pipe assembly. The flexible spline has a spline length, LS, and LS?LG.

Abstract: A polymeric riser cap member includes a central tubular section defining a generally cylindrical bore for receiving a sprinkler riser, the central tubular section having open top and bottom ends, and an annular skirt coaxial with the central tubular section and having an inner diameter larger than an inner diameter of the central tubular section. The annular skirt has an inner surface having internal threads threadably connectable with the externally threaded surface of a tubular riser adapter member of a tubular coupler. The bottom end of the central tubular section has an annular projection disposed opposite and spaced from a portion of the annular skirt. The riser cap member includes an annular recess adapted to receive a seal located in a wall extending laterally between the annular skirt and the annular projection.