Steam Main

a steel pipeline that carries steam from a steam boiler or other steam generator to steam turbines, pumps, heat exchangers, and other devices. The end and low points of a steam main have steam traps to remove the condensate that forms in the pipes. Air escapes located at the high points remove air. The portion of a steam main between fixed supports is designed to compensate for thermal elongation with compensators or by self-compensation. All steam mains are protected with thermal insulation; regardless of the temperature of the steam, the temperature of the outside insulation should not exceed the temperature of the surrounding air by more than 25°C. Steam mains operating at a pressure greater than 200 kilonewtons per sq m (2 kilograms-force per sq cm) must be designed, manufactured, and operated to comply with boiler inspection regulations.