Classification of air pipe valves CPVC Pipe  bai air duct valves can be divided into:
1. One-time regulating valve dao: If the zhuan system is unbalanced, it is a regulating valve designed to achieve the required air volume. It is further divided into: flapper valve, butterfly valve, multi-leaf regulating valve and three-way valve.

2. Frequently opened and closed control valves: mainly include: fresh air valve, primary and secondary air return valve, exhaust valve (including exhaust valve for full exhaust and partial exhaust), etc.
3. Automatic control valve: mainly used for automatic adjustment of fresh air, primary return air and secondary return air. In addition to meeting the requirements of frequently-on-off regulating valves, it should also have good regulating characteristics.