4. Radial seal: Radial seal refers to the sealing of the plunger type globe valve, and its sealing principle is that in the plunger valve, its disc and valve seat are designed according to the principle of the plunger.

3. Spherical seal: Making the valve disc spherical and the valve seat conical, the ball of the disc can rotate freely in the hole of the stem. Therefore, the disc can be adjusted by a certain range of rotation on the valve seat. Since the contact between the two sealing surfaces is almost a line, that is - the line seal, the sealing stress is high and it is easy to seal.

2. Cone seal: Making the sealing surface conical to narrow the contact surface. This kind of seal under the action of a certain sealing force, its sealing specific pressure is greatly increased, and it is easy to achieve the seal. Under the premise of ensuring sealing, the sealing force applied is smaller than that of flat seals. Since the narrow sealing surface is not easy for the disc to fall correctly on the valve seat, the disc must be guided in order to achieve the best sealing performance. After the disc is guided, it can achieve better sealing performance.

Depending on the material of the sealing surface of the globe valve, the globe valve can be sealed with both metal and non-metallic seals. When using metal seals and non-metallic seals, not only the specific pressure of the seal needs to be high, but also the surrounding area needs to be uniform to achieve the required tightness. According to the above requirements, there are various structural designs of the sealing surface, and the sealing principle and sealing force calculation are not the same.