Temperature operated gas valve

A method for operating a valve between two gas volumes, a first volume at an initially higher pressure and a second volume at an initially lower pressure, comprising,

• providing a conduit between the first volume and the second volume,
• providing a restriction in the conduit for which a liquid would have a preference due to surface tension at the restriction, with a meltable solid material closing the restriction,
• when gas is to be moved from the first volume to the second volume, heating the meltable solid material until at least part of the material becomes liquified, allowing gas to pass from the first volume to the second volume, until the pressure differential between the two volumes becomes small, at which time the melted material returns essentially to its preferred initial position by surface tension,
• when valve closure is required, discontinuing heating and allowing the melted material to re-solidify essentially in its initial position thereby to seal the restriction and close the valve, and
• including providing two said restrictions in the conduit, a first restriction and a second restriction, with meltable solid material closing both restrictions, forming two valves in tandem, said second volume comprising an inter valve volume and there being a lower pressure region downstream of the second restriction, and including trapping gas in the inter valve volume with closure of the first restriction and valve then opening the second restriction and valve by heating the meltable solid material and allowing gas to move from the inter valve volume to said lower pressure region downstream, thereby delivering to the lower pressure region a volume of gas determined by the inter valve volume and not requiring equalization of pressures between the first volume and the lower pressure region.

A temperature operated gas valve operable between two gas volumes, a first volume at an initially higher pressure and a second volume at an initially lower pressure, comprising,

• a conduit between the first volume and the second volume, the conduit including a horizontal portion,
• a restriction in the horizontal portion of the conduit forming a narrow passageway for which a liquid would have a preference due to surface tension at the restriction, and
• a meltable solid material within and enclosing the restriction,
• whereby, when gas is to be moved from the first volume to the second volume, the meltable solid material may be heated until at least part of the material becomes liquified, allowing gas to pass from the first volume to the second volume, until the pressure differential between the two volumes becomes small, at which time the melted material will return essentially to its preferred initial position by surface tension, at which point heating may be discontinued to re-solidify the melted material to seal the valve closed.

A temperature operated gas valve operable between two gas volumes, a first volume at an initially higher pressure and a second volume at an initially lower pressure, comprising,

• a conduit between the first volume and the second volume,
• a restriction in the conduit forming a narrow passageway for which a liquid would have a preference due to surface tension at the restriction, and
• a meltable solid material within and enclosing the restriction,
• whereby, when gas is to be moved from the first volume to the second volume, the meltable solid material may be heated until at least part of the material becomes liquified, allowing gas to pass from the first volume to the second volume, until the pressure differential between the two volumes becomes small, at which time the melted material will return essentially to its preferred initial position by surface tension, at which point heating may be discontinued to re-solidify the melted material to seal the valve closed, and
• including two said restrictions in the conduit, a first restriction and a second restriction, with multiple solid material closing both restrictions, forming two valves in tandem, said second volume comprising an inter valve volume and there being a lower pressure region downstream of the second restriction, whereby the first restriction may initially be opened by heating, so that gas flows into the inter valve volume and is trapped between the two valves when the first valve is closed, then the second restriction may be opened by heating and melting the meltable solid material therein, thereby allowing gas to move from the inter valve volume to said lower pressure region downstream.

A temperature operated gas valve operable between two gas volumes, a first volume at an initially higher pressure and a second volume at an initially lower pressure, comprising,

• a conduit between the first volume and the second volume,
• a restriction in the conduit forming a narrow passageway for which a liquid would have a preference due to surface tension at the restriction, and
• a meltable solid material within and enclosing the restriction, with a heating means adjacent to the meltable solid material, for elevating the temperature of the meltable solid material beyond its melting point when the valve is to be opened, the heating means comprising an electrical resistance wire passing directly through the restriction,
• whereby, when gas is to be moved from the first volume to the second volume, the meltable solid material may be heated using the electrical resistance wire until at least part of the material becomes liquified, allowing gas to pass from the first volume to the second volume, until the pressure differential between the two volumes becomes small, at which time the melted material will return essentially to its preferred initial position by surface tension, at which point heating may be discontinued to re-solidify the melted material to seal the valve closed.

A method for operating a valve between two gas volumes, a first volume at an initially higher pressure and a second volume at an initially lower pressure, comprising,

• providing a conduit between the first volume and the second volume,
• providing a restriction in the conduit for which a liquid would have a preference due to surface tension at the restriction, with a meltable solid material closing the restriction, the conduit being essentially symmetrical on either side of the restriction,
• when gas is to be moved from the first volume to the second volume, heating the meltable solid material until at least part of the material becomes liquified, allowing gas to pass from the first volume to the second volume, until the pressure differential between the two volumes becomes small,
• when the pressure differential between the two volumes is small, returning the melted material essentially to its preferred initial position solely by surface tension, and
• when valve closure is required, discontinuing heating and allowing the melted material to re-solidify essentially in its initial position thereby to seal the restriction and close the valve.