From the composition of pipe system, cast iron drainage pipe can be divided into three categories: straight pipe, pipe fittings and auxiliary parts. Direct pipe is the main component of the pipe system; various kinds of pipe fittings guarantee the function of the drainage system (collection, steering, ventilation, closed water closure, energy dissipation and pressure relief, inspection and clearing, etc.); auxiliary parts mainly play the connection and sealing role. W1 type is a commonly used connection form, with small radial size (no flange), easy to layout, space saving, length can be on the spot, sectionProvincial pipe, convenient disassembly, easy maintenance and replacement and other advantages.
