This section is from the book "A Practical Treatise On The Joints Made And Used By Builders", by Wyvill J. Christy. Also available from Amazon: Practical treatise on the joints made and used by builders.
Flexible Joint is formed between two pipes with plain ends united with a piece of india-rubber tubing.
This is the ordinary copper-bit joint already described.
Flush Soldered Joint occurs in lead flats, etc, where it is found necessary and safe to unite sheets without providing for expansion. It is made by sinking a chase or groove from ¾ in. to 1 in. wide and about ½ in. to ¾ in. deep in the boarding, according to its thickness and that of the lead, and bending the edges of the sheets into it, allowing a little overlap, and nailing them down to the chase with clout nails. The usual scraping, soiling, etc, having been performed, solder is then poured into the groove over the edges and floated and smoothed with the iron, and all wiped smooth and flush.
This term is used for a lap joint crossing the direction of the current.
Hollow Roll Joint is used on flats in the direction of the fall, and is made by turning up against one another the edges of two sheets of lead, allowing one to stand a little higher than the other so as to be bent over it, and then rolling the two over together, as shown in Fig. 144, with the tingles or latchets between them. Wood rolls are thus dispensed with.
This is made when from 3 in. to 6 in. of one sheet or strip are laid over the upstanding edge of another, as in fixing aprons or flashings. It likewise occurs when the edges of lead roof coverings are dressed flat over those of others, as in heading joints or in the corresponding junctions which are formed when more than one length or strip are required in covering hips, ridges, and valleys, with the same metal. In ancient times, sheets of lead, when circumstances would allow, were lapped over the ridge of a roof so as to hang some little way down on the opposite side.
There are three varieties of this joint for which the plumber provides the lead, but he rarely makes them, as this artificer usually employs solder or cement for jointing, excepting when burning in with molten lead. One variety is run with molten lead, another is made by inserting into the pipe socket or slipping over the spigot a ring of cast lead and then forcing the two ends tightly together, whilst the remaining one consists in placing an intervening plate of lead between bearing surfaces to obtain a fine joint, equally distributed pressure, exemption from damp, or a conjunction of one or more of these desiderata.
A round wiped soldered pipe joint, in which the length of the egg-shaped protuberance or joint is about one and a quarter times its breadth.