A Practical Manual On Sea Water Distillation
With A Description Of The Necessary Machinery For The Process

92 SEA WATER DISTILLATION. required to provide the amount of surface deemed neces- sary. The larger tube is also more rigid, and, therefore, less liable to be bent. The larger tube also allows the water inside to escape more freely. 53. Perhaps it is best to fix on a diameter of, say, 1| inches when the tubes are about 10 to 12 feet long, and say, 2| inches if the tubes are in about 20 feet lengths. The size of the coil, however, may differ with various makers, according to the shape and manner in which the coils are fitted. Fig. 9. 54. Whatever may be the size of the coil, it is most important that the tube or coil—that is, each item- should be in one piece solid drawn throughout. It is also most important that the joints at the end of each item—that is, the steam and water ends of the coils— should be sound, reliable, and durable, yet easily broken and re-made. An effective joint is made by expanding the tubes in gun-metal elbows or end pieces, then for these end pieces to be screwed into the casing where the steam and water pockets are. Such a joint is of the same class as an ordinary union joint (see Fig. 9).