WIRELINE RETREIVABLE GAS LIFT VALVES Like the conventional gas lift valves, UDT line of wireline retrievable gas lift valves include, casing-pressure-operated, tubing-pressure operated (fluid-operated) types in a full selection of sizes. Each valve has a large dome volume and Monel multi-ply bellows. Every valve is constructed of stainless steel and monel, selected on the basis of corrosion resistance and strength. Bellows are silver-soldered by induction soldering technique and all valves are factory tested for high reliability. Wireline retrievable gas lift valves provide self-contained packing as a sealing means in retrievable mandrels and each valve has integral check-valve to prevent flow between tubing and casing.