Gas riser apparatus

A riser apparatus for connecting a gas service line disposed below ground level and a gas receiving means disposed above ground level, the riser apparatus comprising:

• a tubular element having an internal bore, a first end which is adapted to be disposed above ground level, and a second end which is adapted to be disposed below ground level, the first end of the tubular element being adapted for connecting the tubular element with the gas receiving means, the tubular element internal bore having a constant cross section from the first end to tapered portion at which tapered portion the cross section contracts along a cam surface, the tubular element being swagged adjacent the tapered portion to define an annular stop which defines a smaller internal cross section than the tapered portion;
• a gas conducting conduit having a first end and a second end, the conduit extending slidably through the second end of the tubular element, the annular stop, and the tapered portion with the first end of the conduit disposed within the constant cross section portion of the internal bore of the tubular element, the second end of the conduit being adapted to be connected with the service line;
• an annular collar engaging the conduit adjacent its first end and having an external cross section which is slidably receivable in the constant cross section portion of the internal bore;
• an annular, resilient gas seal which is slidably receivable in the constant cross section portion of the internal bore of the tubular element and compressed by the tapered portion such that the resilient seal prohibits the flow of gas between the conduit and tubular element below the resilient seal, the resilient seal being disposed adjacent the annular collar;
• a retaining ring which slidably receives the conduit therethrough and which has an external cross section which is slidably receivable in the internal bore and which abuts the annular stop to limit sliding receipt, the retaining ring being disposed adjacent the resilient seal such that the retaining ring, resilient seal, and the annular collar are slidably received in the internal bore;
• and,
• inward projecting deformations of the tubular element which deformingly engage the annular collar to lock the annular collar and tubular element against relative sliding movement such that the resilient seal is compressed between the annular collar, the tapered portion, and the retaining ring;
• whereby gas may be conducted through the second and the fist end of the conduit, through the portion of the internal bore of the tubular element above the resilient seal and through the first end of the tubular element.