Abstract

This paper is concerned with the damage that can occur in steam distribution systems due to high pressures generated by condensate being swept through pipework by high pressure steam. Two cases have been considered. The first situation is one where an isolated slug of water is propelled through a pipeline by high pressure gas and impacts against an obstruction, in this case an orifice plate. In the experimental tests compressed air was used to propel a slug of water through a 13 m long 50 mm diameter pipeline; impact pressures of up to 300 bar were generated. The second case considers the damage that is found to occur in a particular component of a steam system - a steam float trap. Damage was inflicted by slug impact and by pressures generated from water hammer in the main line. Although water slugs are often blamed for steam trap failures, the damage inflicted by this mechanism was inconsistent with that found in practice and it is concluded that they are not responsible. Water hammer in the main line could, however, be the cause of failure.