52 



VETERINARY HYGIENE 



internal diameter, while that of a stone- ware pipe is one-twelfth. 

 Stone-ware pipes, 4, 5 and 6 in. in diameter, are made 2 ft. 6 in. 

 long, larger sizes, 3 ft. long. All fireclay pipes are made in 3 ft. 

 lengths. 



Stone-ware pipes are more brittle and more difficult to cut than 

 fireclay. In large pipes, when the flow is strong and continuous, 

 cases have been found where the internal coat of glaze on fireclay 

 pipes has been worn through, but this would seldom happen in 

 house or stable drains. 



Traps and other drain fittings are made of the same materials 

 as those used for pipes. 



Cast-iron Pipes. In connection with the drainage of buildings 

 three classes of cast-iron pipes are commonly used. Rain water 

 pipes are intended only for conducting the discharge from roof 



FIG. 10. Soil and Waste Pipe. 

 Staved Joint. 



FIG. 11. Heavy Drain Pipe. 

 Staved Joint. 



gutters to the ground level. They are of very light metal, and the 

 faucets are not suitable for lead caulking. These pipes should never 

 be used for soil or waste pipes. Waste and soil pipes of 3 /ie inch 

 and inch respectively are cast with care to ensure a smooth internal 

 surface. The sockets are of sufficient width and strength to permit 

 the joint being properly caulked. The pipes are made in 6 feet 

 overall lengths. 



Cast-iron Drain Pipes are made of specially heavy design with 

 extra strong sockets. The joint is made of rope yarn and molten 

 lead properly caulked into the annular staving space. This joint 

 is the most air-tight, and there is little possibility of the leakage 

 of sewer gas. The smooth internal surface which is necessary 

 in a drain pipe is obtained by a special treatment of the core. All 

 bends, junctions, &c., are made with very easy curves to facilitate 

 the flow. 



The strength of cast-iron drain pipes, combined with the elas- 

 ticity of caulked lead joints, enables the pipes and joints to sustain 

 without damage subsidence of ground and other accidents which 



