The water supply of towns and the construction of waterworks : a practical treatise for the use of engineers and students of engineering / by W.K. Burton ; to which is appended a paper on the effects of earthquakes on waterworks by John Milne.

Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: The water supply of towns and the construction of waterworks : a practical treatise for the use of engineers and students of engineering / by W.K. Burton ; to which is appended a paper on the effects of earthquakes on waterworks by John Milne. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    the thickness added to cover contingencies is reduced from a little less than ^rd of an inch to ^th of an inch. The result is to make small pipes for light pressures somewhat less in thickness than the table gives to make large pipes, especially those for high pressures considerably greater in thickness. For example, the thickness of 4, 30 and 72 inch pipes, for the several pressures given in the above table would come out as follows :— 4 inch pipe \\ § and T7g 30 inch pipe . \ . 1-^- and H 72 inch pipe . If . 2\ and 3\ The reasons for thinking that this formula might, perhaps, be an improvement on the one from which the table is calculated, is that, with the great skill that has in the present day been acquired in pipe-casting, £ inch a side ought really to be an ample allowance for contingencies, whilst 4 is somewhat a small factor of safety. In the case of the small pipes the addition of ^rd of an inch added to cover contingencies, constitutes so large a proportion of the whole thickness of the pipe, that this is of no consequence. In the case of very large pipes it is otherwise. The ^rd in. added forms only a small fraction of the total thickness, and the factor of safety is low. Against this it may be put that ramming to the extent of 100 lbs. on the square inch is practically impossible in very large pipes as used in waterworks, because the valves on such pipes can only be closed very slowly, whilst the sudden closing of a valve on a small branch from a large main does not retard the flow of water sufficiently to produce serious ramming. On the other side, again, it may be argued that the danger from the bursting of a very large main is so serious, that every possible precaution should be taken to prevent it. On the whole it seems difficult to decide on one formula in preference to another. Special Pipes.—Besides flanged pipes already mentioned, which may really be looked on as special pipes, many other special castings are needed in connection with distribution systems, besides valves and other fittings of that order. These are chiefly T pieces, bends, Y pieces, and so forth. A set of these is illustrated in Plate XLI. (Figs. 210—215), and scarcely need explanation. The sleeve, Fig. 215, is used for connecting two spigot ends together. It is occasionally convenient to do this when pipes are laid at first; it is often convenient, when a pipe has to be removed and replaced by a new one. With the regular spigot and socket, the