use, it inevitably condenses to some extent in the steam pipes and cylinders outside the boiler, causing a disproportionate loss of steam volume as it does so; and it places a heavy demand on the boiler. Superheating the steam dries it effectively, raises its temperature to a point where condensation is much less likely and increases its volume significantly. Added together, these factors increase the power and economy of the locomotive. The main disadvantages are the added complexity and cost of the superheater tubing and the adverse effect that the "dry" steam has on lubrication of moving components such as the steam valves. Shunting locomotives did not generally use superheating. The normal arrangement involved taking steam after the regulator valve and passing it through long superheater tubes inside specially large firetubes of the boiler. The superheater tubes had a reverse ("torpedo") bend at the firebox end so that the steam had to pass the length of the boiler at least twice, picking up heat as it did so. Processing Other potential uses of superheated steam include: drying, cleaning, layering, reaction engineering, epoxy drying and film use where saturated to highly superheated steam is required at one atmospheric pressure or at high pressure. Ideal for steam drying, steam oxidation and chemical processing. Uses are in surface technologies, cleaning technologies, steam drying, catalysis, chemical reaction processing, surface drying technologies, curing technologies, energy systems and nanotechnologies. The application of superheated steam for sanitation of dry food processing plant environment has been reported. Superheated steam is not usually used in a heat exchanger due to low heat transfer co-efficient. In refining and hydrocarbon industries superheated steam is mainly used for stripping and cleaning purposes. Pest control Steam has been used for soil steaming since the 1890s. Steam is induced into the soil which causes almost all organic material to deteriorate (the term "sterilization" is used, but it is not strictly correct since all micro-organism are not necessarily killed). Soil steaming is an effective alternative to many chemicals in agriculture, and is used widely by greenhouse growers. Wet steam is primarily used in this process, but if soil temperatures above the boiling point of water are required, superheated steam must be used. See also Superheated water References Water Steam power ja:水蒸気#飽和蒸気と過熱蒸気