A STUDY OF HYDRAULIC IMPACTS CAUSED BY CONDENSATE IN STEAM DISTRIBUTION-SYSTEMS

This paper describes an investigation into a problem associated with s team distribution systems where condensate is swept through a pipeline by high-velocity steam, causing considerable damage when it impacts u pon an obstruction. Two cases have been considered. The first is where an isolated slug of water is swept through a pipeline by high-velocit y steam and impacts against an orifice plate. In experimental tests co mpressed air was used to propel a slug of water through a pipeline 13 m in length and 50 mm in diameter; impact pressures of up to 300 bar w ere generated. The second case was more specific and considered the da mage that occurs in steam traps. Tests were carried out in which damag e was inflicted upon a float trap and a bucket trap by slug impact and by water hammer generated in the main pipeline. Although direct impac ts by water slugs are often blamed for steam trap failures, the damage inflicted by this mechanism was not consistent with that found in pra ctice and it has been concluded that they are not responsible. Water h ammer in the main pipeline could, however, be the cause of failure. Du ring the tests it was observed that the internal design of the body of the trap could produce a beneficial cushioning effect and this, toget her with the improved construction techniques for float traps, may ove rcome the problem of collapsing floats.