سیستم های Drain در خطوط بخار TDP-1

3.7.3 Drain lines and drain valve ports shall be sized for the maximum amount of water to be handled under any operating condition. However, they shall never be less than  3 ⁄ 4 in.(19 mm) internal diameter. Drain lines, including the connections for cold reheat and motive steam attemperator systems, shall have an inside diameter of not less than 11 ⁄ 2 in. (38 mm). Care shall be taken not to use nominal pipe or valve sizes without clearly determining that the inside diameter meets this minimum dimension.

3.7.6 Drain pots are required to be used when level control of a drain line is required. Drain pots may also be used to assist gravity drainage for systems with low-pressure differentials. If used, drain pots shall be fabricated from 4 in. (100 mm) or larger diameter pipe for most steam lines except for cold reheat drain pots, which shall be 6 in. (150 mm) or larger in diameter. Drain pots shall be at least 9 in. (230 mm) long but shall not be longer than is required to install level detection equipment. Drain lines and valves shall be sized as discussed earlier in para. 3.7.

3.7.7 The pot and connecting piping shall be fully

insulated.