Hazardous location expansion fitting

Claim 1

A hazardous location expansion fitting comprising (a) a metallic body having a first end suitably configured for rigid coupling to a first member by means for preventing the rapid ingress or egress of the external or internal gases, respectively, through said rigid coupling; (b) a head member coupled to a second end of said metallic body member and suitably configured with a passage therethrough for a liquid tight relationship with a conduit member placed therethrough; (c) said metallic body member having an interior chamber with a uniform cross section for at least a portion of the length of said body member, said interior chamber having a diameter greater than that of said passage through said head member; (d) a metallic bushing having a first outer surface configured to mate with said uniform cross section of said interior chamber of said body member and said bushing dividing the interior chamber into two spaced subchambers, said bushing defining with said body member a leakage control through passage from one of the two subchambers to the other subchamber of sufficiently small size and sufficiently great length said through passage being in heat transfer relationship with said body member to cool the gases passing through said leakage control through passage below explosion igniting temperature; and wherein (e) said bushing includes coupling means for coupling it to an end of said conduit member which enters said body member from said second end thereof and through said passage through said head member whereby the end of said conduit member which is coupled to said bushing is positioned interior of said body member and can reciprocate with respect to said head member and said body member and concomitantly cause said bushing to reciprocate with respect to said body member.