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.
As a rule this is not recommended for uniting gas-pipes, but when it is used the same procedure must be followed as described under the Plumber, the essential point being to properly tin the bit and the parts to be joined with a few drops of solder, so as to get perfect union or physical adhesion between the tinning and the work, and after that perfect cohesion between the tinning and the solder which is melted off from the stick or cake with the bit, and dexterously kept hot, distributed, sweated and smoothed by its application.
The same as ball and socket joint. Elbow Joint is formed with an elbow piece, which may be of brass or iron, and round or square. The latter variety is represented in Fig. 81. Sharp elbows are inferior to easy bends for the passage of gas in branch pipes, etc. Hence lead pipes are in this respect superior to iron, whilst rust often accumulates in the latter and causes inconvenience. A T-piece with one of its branches stopped with a screw plug is a handy substitute for an elbow, inasmuch as it enables water or rust to be removed. Hydraulic Joint is the same as a water joint. It consists in making a sliding pipe remain air-tight by means of a water lock. Fig. 165 shows the joint as ordinarily used in gasaliers, the outside and inside pipes being parts of the gasalier that are supported by weights or counterpoises and chains suspended from the ceiling, and therefore capable of sliding, whilst the intermediate pipe, which receives the gas from the branch pipe and dips into the water and forms the seal, does not slide but is permanently fixed to the top or ceiling plate of the gasalier.
Knee Joint is another name for elbow joint, and sometimes applied to a joint formed by means of an elbow nose-piece.
Iron barrel or iron tubing is united by this artificer in the same way as by the Smith, excepting that washers must in all cases be used between flanges. Lead pipes and compo. tubing are connected up as described under Blowpipe Joint. Cast iron mains are laid by main-layers similarly to water mains.
In connecting the service with the meter this occurs as a sort of T-joint, and is made by stopping the end of the lead pipe from the meter and inserting the cap and lining into its side, instead of connecting it end on to the service. In bending the pipe on to meter care should be taken not to contract its fullway.
Screw Joint occurs in uniting wrought iron barrel and fittings to one another, and brass tube to bracket backs, swivels, etc, and all kinds of fittings to straight and elbow nose pieces, etc, etc. The remarks under Socket Joint are here applicable.