Asbestos Cement at www.japanese-home-gardens.com

While various materials were formerly used for pipes—wood, wrought iron, cement-lined stovepipe, wrought steel, steel plate, reinforced concrete, galvanized steel, and cast iron—the present trend is to use cast-iron pipe (cement lined in regions where the water is aggressive) or asbestos cement-cement pipe. The sizes of pipe where hydrants are to be served should never be less than 8 inches, except in small, limited systems. Street mains larger than 48 inches are uneconomical, although 72-inch pipes are sometimes used, as in Jersey City and in Brooklyn. Large cast-iron pipes are subject to shrinkage and other stresses, which make them less reliable than steel or reinforced concrete in cases of heavy pressure or traffic loads.

The resulting cement, produced from the formerly discarded grappiers, was of much higher quality than that obtained from the unsintered material. This fact was firmly established by the English cement manufacturer L. C. Johnson in 1845, and the term "portland cement" has since been applied solely to the cement made from the sintered material. This period marks the real beginning of the portland cement industry.

Glove Valves are made with solid and renewable discs; in the former case they are of brass and in the latter of soft metal asbestos cement or packing of some kind. Fig. 9 represents the most common type of globe valve. It is provided with a vulcanized asbestos cement disc ring. The ring is composed of the fibre of asbestos cement, to which is added a waterproof vulcanizing material, making a very durable packing, which will not crack or flake off. It is held centrally on its seat by guides cast on the body of the valve. It is also secured to the spindle without the use of nuts, screws, pins or wires.