Steel buriable gas fittings connect natural and LP gas lines in underground installations and above-ground pipes. These compression tube fittings include preassembled bodies, nuts, and sleeves for quick installations. Sleeves grip tubing as the nut tightens compressing the sleeve for a tight seal. Fittings connect without tools. Steel, a manmade alloy, is hard and resilient with a wide temperature range and good corrosion resistance in high-humidity environments.