This drain tube is used on gas, electric, or oil fired residential water heaters to safely drain water discharged from the heater's temperature and pressure relief valve. It connects to the drain connection on a side-mounted relief valve that has up to 105,000 BTU/hr rating, and has a drop length of 48 in. It hand tightens to the relief valve outlet, requiring no special tools or fittings. It is UPC and IAPMO listed, and ASME A112.4.1 approved. It meets Department of Housing and Urban Development requirements.