In large hot-water supply systems the cold-water lines connect into a header, the hot-water lines into another, and the circulation pipes into another.

This makes the work very systematic and easily cared for. Fig. D shows the general arrangement of a header, with its branches, each supplied with a shut-off, and each branch also provided with a drip connecting into a main drip, the latter emptying into an open fixture.

The same general arrangement of headers, branches, drips, valves, etc., may be, and often is, employed to great advantage in connection with the hot- and cold-water supply of a residence.

In connection with high-grade residence work, a very neat and artistic piece of work can be performed on these headers by using polished brass pipe and fittings, and additional neatness in appearance may be obtained by bending the pipes at changes in direction, instead of performing the work with fittings. Better results can also be obtained from this method for the reason that there is less friction encountered in smooth bends than in bends made with fittings.

The employment of these methods is almost a necessity on large work, as in such work the supply piping is of such a complex nature that it cannot safely be installed other than in the most systematic manner.