Supply tank for inflammable gas with protective cap

1 . A refillable supply tank for an inflammable gas comprising:

a tank body defining a container with a wall surrounding a hollow interior for receiving the gas and an opening in the wall;

a valve support component mounted in the opening and defining a passage therethrough extending from an end face of the valve support component into the interior of the tank body;

a valve body in the passage arranged to provide a primary seal of the passage against escape of the gas and operable to open the passage to allow the escape when required;

and a valve protection cap for covering the valve support component with the valve body therein;

the valve protection cap including an upper wall and at least one depending peripheral wall which extends around the valve support component;

wherein the upper wall of the valve protection cap includes an elongate projecting pin member projecting from the upper wall of the valve protection cap to a remote end of the projecting pin member spaced from the upper wall;

wherein the projecting pin member extends into and engages into the passage to provide a secondary seal with the passage to supplement the primary seal of the valve body in the passage;

wherein the projecting pin member is defined by an annular sleeve surrounding a hollow interior where the hollow interior of the sleeve extends along the projecting pin member from the remote end of the projecting pin member to the upper wall.

2 . The refillable supply tank according to claim 1 wherein the valve support component has an outer peripheral surface of a larger diameter than an outer peripheral surface of the valve receptacle so that said at least one engagement surface of the valve protection cap is spaced outwardly of the outer peripheral surface of the valve receptacle.

3 . The refillable supply tank according to claim 2 wherein said at least one depending peripheral wall is spaced outwardly of the outer peripheral surface of the valve receptacle so as to define an open shoulder area outside the end face of the valve receptacle underneath the upper wall of the valve protection cap which acts as a crush area to receive impact loads.

4 . The refillable supply tank according to claim 1 wherein the upper wall of the valve protection cap at the end face of the valve receptacle includes a ring underneath the upper wall which extends into and engages the passage to transfer loading between the valve receptacle and the valve protection cap.

5 . The refillable supply tank according to claim 1 wherein the valve protection cap includes an annular skirt extending downwardly from said at least one depending peripheral wall into engagement with the wall of the tank surrounding the opening so as to transfer impact loads from the valve protection cap to the wall of the tank.

6 . The refillable supply tank according to claim 1 wherein the outside of the valve support component includes an external male screw thread and wherein said at least one engagement surface of the valve protection cap defines a female thread on a plurality of separate radially outwardly displaceable sections whereby the valve protection cap can be pushed axially on to the external male screw thread by outward displacement of the sections and can be removed rotationally by unscrewing the sections from the external male thread.

7 . A refillable supply tank for an inflammable gas comprising:

a tank body defining a container with a wall surrounding a hollow interior for receiving the gas and an opening in the wall;

a valve support component mounted in the opening and defining a passage therethrough extending from an end face of the valve support component into the interior of the tank body;

a valve body in the passage arranged to provide a primary seal of the passage against escape of the gas and operable to open the passage to allow the escape when required;

and a valve protection cap for covering the valve support component with the valve body therein;

the valve protection cap including an upper wall and at least one depending peripheral wall which extends around the valve support component;

wherein the upper wall of the valve protection cap includes an elongate projecting pin member projecting from the upper wall of the valve protection cap to a remote end of the projecting pin member spaced from the upper wall;

wherein the projecting pin member extends into and engages into the passage to provide a secondary seal with the passage to supplement the primary seal of the valve body in the passage;

wherein the projecting pin member is defined by an annular sleeve surrounding a hollow interior where the hollow interior of the sleeve extends along the projecting pin member from the remote end of the projecting pin member to the upper wall; and

wherein the annular sleeve has an outside surface extending from the upper wall to the remote end which outside surface tapers from the upper wall to the remote end so that a diameter of the outer surface at the upper wall is greater than a diameter of the outer surface at the remote end and wherein the annular sleeve has an inside surface surrounding the hollow interior extending from the upper wall to the remote end which inside surface tapers from the remote end to the upper wall to so that a diameter of the inside surface at the upper wall is less than a diameter of the inside surface at the remote end.

8 . The refillable supply tank according to claim 7 wherein the passage carries an O-ring seal surrounding and engaging the outer surface of the projecting pin member to form the secondary seal therewith, wherein the valve protection cap is arranged such that release of pressure from the tank body through the passage caused by leakage from the valve body causes movement of the upper wall in a direction away from the passage and wherein the projecting pin member is arranged such that the movement of the upper wall under the pressure is insufficient to cause release of the secondary seal between the projecting pin member from the O-ring seal.

9 . The refillable supply tank according to claim 8 wherein the diameter of the outer surface at the O-ring seal is arranged such that the outer surface engages and compresses the O-ring seal to form the secondary seal.

10 . The refillable supply tank according to claim 9 wherein the movement of the upper wall under the pressure is insufficient to cause the diameter of the tapered outer surface at the O-ring seal to release from engagement and compression of the O-ring seal to form the secondary seal.

11 . The refillable supply tank according to claim 8 wherein the projecting pin member has a length from the O-ring seal to the remote end of at least 3 mms and preferably at least 5 mm.

12 . The refillable supply tank according to claim 1 wherein the valve body in the passage includes a projecting element extending longitudinally of the passage and operable to open the passage to allow the escape of the gas when required and wherein the projecting element extends into the hollow interior to a position beyond the remote end of the projecting pin member.

13 . The refillable supply tank according to claim 7 wherein the valve body in the passage includes a projecting element extending longitudinally of the passage and operable to open the passage to allow the escape of the gas when required and wherein the projecting element extends into the hollow interior to a position beyond the remote end of the projecting pin member.