In building plumbing systems, risers are categorized into: conventional single riser, conventional double riser, and special single-riser systems.

　　In building plumbing systems, the vertical drainage risers are categorized into: conventional single-riser systems, conventional dual-riser systems, and special single-riser systems. The single-riser drainage system allows building wastewater to be discharged through just one pipe, utilizing specialized fittings that enable both drainage and ventilation within the same pipe. This innovative technology is primarily designed for multi-story and high-rise buildings with 10 or more floors, eventually replacing the conventional dual-riser system.
　　The special single-stack systems are divided into two types: the S-Trap system and the Enhanced Cyclonic System. Unlike the S-Trap, the cyclonic system is based on the following principle: when water flows vertically inside the pipe, it moves along the inner wall of the pipe. However, if the water flow forms a vortex, an air channel naturally develops at the center of the riser, which not only facilitates smoother airflow but also ensures unobstructed drainage.

• B型法兰管件排水系统