Patent ID: 7740284

Claim:
A vented gas riser apparatus conducting pressurized gas from a gas supply source line located below ground level to a delivery point disposed above ground level comprising: a) an elongated gas carrier pipe, said carrier pipe having a first pipe end disposed below ground level and sealingly connected at a first point of connection to said gas supply source line and having a second pipe end disposed above ground and sealingly connected to said delivery point whereby pressurized gas may flow through said carrier pipe from said gas supply source to said delivery point; b) a generally cylindrical fluid tight gas riser protective casing, said casing having a first casing end disposed below ground level and second casing end disposed above ground level, said casing disposed around said carrier pipe and creating a gas escape passageway in an elongate annular space between said carrier pipe and said casing; c) a containment chamber disposed below ground level, said containment chamber surrounding said first point of connection and creating a confined space which has, as its only egress, a fluid connection to said gas escape passageway whereby any gas which may leak from said first connection point will be captured by said containment chamber and directed into said gas escape passageway; and d) a riser transition head having a first head end sealingly connected to said delivery point and having a second head end connected to said second casing end, said second head end including at least one vent passageway which provides a fluid connection with said gas escape passageway and with the atmosphere whereby any gas which leaks into said containment chamber is directed through said gas escape passageway and through said at least one vent and into the atmosphere, wherein said riser transition head includes a riser casing sleeve on to which a plurality of crimps are provided to connect said head to said riser casing with said at least one vent passageway being formed by the space between adjacent crimps.