Plumbing practice / by J. Wright Clarke.

  • James Wright Clarke
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: Plumbing practice / by J. Wright Clarke. Source: Wellcome Collection.

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    at A, Figure 8, and then standing it upright with more sand on its outside, with the necessary space indented to the size and form of the flange required. The lead must be red hot and free from oxide, or I what is commonly called dross, and must be poured as quickly as possible until the end of the pipe is completely fused, the superfluous molten lead flowing away as before described. Even after it is supposed that the union is complete, the pouring should be continued for some Httle time, as it frequently occurs that the part which can be seen at B is fused long before the part at C, and hence the pipe is weak just where a strain may be brought to bear when making a bolted connection. It is always necessary to cast these flanges a little thicker than required, as the lead shrinks in cooling, and leaves the surface so rough that it requires trimming. When I pouring the lead on to the part to be united, good-sized ladles I should be used, and great care must be taken not to disturb the i sand by pouring from too great a height; doing this also cools ! the lead. For making large work it is sometimes necessary for two or three men to be pouring at the same time, and others fetching more melted lead to take their places in pouring. There must not be any delay, as the lead gives up its heat to the ; surroundings so quickly that it is soon set. The earliest record of any patent for making lead pipes appears to have been granted, a.d. 1741, to James Creed, who invented a machine for cutting sheet-lead into any required breadth, for the making of water-pipes of any diameter and strength, * * * and the slips of lead so cut are turned up into pipes by means of rollers of wood, iron, etc., * * * and at the same time the edges „ are scraped fit for soldering by a tool fixed on the frame. There must have been some improvement after this in the making of lead pipes, for in the year a.d. 1790 a patent was granted to John Wilkinson, whose specification says : I cast the lead iu !lengths, as is practised in the common way. This is put upon a polished rod or round mandrel of iron, or any other metal, such mandrels being made of different lengths and diameters, according to the size that is wanted. This rod or mandrel, with the cast- I lead upon it, is put repeatedly through or between rollers with . grooves of different sizes, according to the external diameter required, and extended to the length or thickness ordered, or drawn