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

*54 SEA WATER DISTILLATION. 13. It is usual to test the pumps as follows :—The steam cylinders and all parts subject to boiler pressure are proved to about 450 lbs. per square inch. The cir- culation pump to 50 lbs. per square inch. The force pumps generally to about 200 lbs. per square inch. 14. The pumps supplied for land distilling apparatus are practically on the same principle, but they will be referred to more in detail when the subject of multiple distilling apparatus is dealt with, the type of apparatus best suited for land work. 15. The steam to drive the pumps comes from the boilers on board, and as the exhaust steam usually goes into the exhaust steam pipe, the pump should be arranged to work with a back pressure of about 25 lbs. per square inch on the exhaust. (c) The Connections. 16. It is usual for the distilling apparatus to include all the fittings, mountings, and connecting pipes. All pipes for steam and water are brought up to the branches. A drawing is usually sent to the builders of the ship, or contractors for the main or auxiliary engines, as the case may be, for them to provide the necessary space for the apparatus on board. 17. It is well to bear in mind that the pipes leading to and from the apparatus must be of proper size—that is, not too small—e.g., two pipes must not run into one of the same size, at some distance from the apparatus, as this might create a back pressure, and cause troubles and difficulties, sometimes not very easy to trace. 18. All connecting pipes should be made of copper as usual, and all pipes through which brine passes should be