DrainsWhen fitting drains the following should be noted:-Drain lines must not bypass any stop valves or fittings, particularly those related to the emergency stop system.-Neither water nor low temperature steam must be able to enter the turbine through the drains.The runs of the drain lines are determined on size to fit in with the plant layout. The drain valves must always be easily accessible.The minimum nominal size of the drains should be NW 15. Drain lines which are also used to warm through pipelines and the turbine should be NW 40 minimum size.