The check valve can be classified into lift check valve, swing check valve, butterfly swing check valve, pipeling check valve, slow-closed check valve and diaphragm type check valve, etc. Belowing is a detail present of  the categories:

1. Lift Check Valve
The structure of lift check valve is generally the same as stop valve, valve clack lifting moving along the pipe center line. The motion is steady, but great resistance to the fluid, thus the lift check valve is suitable to small diameter pipe system.

2. Swing Check Valve
The valve clack of swing check valve rotates around the spindle. Its resistance to fluid is smaller than the lift check valve and the valve is suitable to the large diameter pipe system. According to the number of valve clack, the swing check valve can be divided into single-lobe type which is suitable to the medium diameter pipe system part, double-lobe type, and multi-lobe type. If combining the large pipeline with the single-lobe type swing check valve, it is a best choise to apply a slow-closing check valve to reduce the knocking pressure. The double-lobe type is suitable to the medium and large diameter. The butt clamp swing check valve features with small size, light weight, developed very fast. And the multi-lobe check valve is suitabe to the large diameter pipeline.

3. Butterfly Swing Check Valve
The structure of butterfly swing check valve is similar to butterfly valve with the advantages of simple structure, small fluid resistance and small knocking pressure.

4. Diaphragm Type Check Valve
There exist several structure of diaphragm type check valve, all of which apply the diaphragm as the disc. Due to its excellent waterproof property, simple structure, low cost, in recent years, the diaphagm check valve is developed speedly, but be limited by the diaphragm material of the using temperature and pressure.