As an indispensable component in mechanical equipment, the performance of mechanical seals directly affects the operational efficiency and safety of the equipment. According to different classification criteria, mechanical seals can be classified into multiple types to meet sealing requirements under different working conditions. This article will introduce the classification of mechanical seals from several main aspects.

 

1、 Classified by the number of sealing end faces

 

Single end mechanical seal has a pair of sealing end faces, namely a moving ring and a stationary ring. This sealing structure is relatively simple and suitable for situations with general sealing requirements. The sealing performance of a single end mechanical seal mainly depends on the fit of the sealing surface and the compensation ability of the elastic element.

 

Double end mechanical seals have two pairs of sealing end faces, and compared to single end mechanical seals, their sealing performance is superior. Double end mechanical seals are suitable for applications with high sealing requirements, such as flammable, explosive, toxic media, and high vacuum environments. In addition, double end mechanical seals can effectively prevent medium leakage into the external environment, improving the safety of equipment.

 

2、 Classified by installation method

 

The spring of the external mechanical seal does not come into contact with the sealing medium, avoiding the problem of spring corrosion caused by the medium. This sealing method is suitable for situations where the medium is highly corrosive and can extend the service life of the seal.

 

The spring of the built-in mechanical seal is in direct contact with the sealing medium. Although this installation method may cause the spring to corrode due to the medium, its compact structure is suitable for situations with limited space.

 

3、 Classification by sealing medium flow direction

 

Internal flow mechanical seals allow the sealing medium to flow from the inside to the outside, making them suitable for situations where it is necessary to prevent medium leakage. This sealing method ensures that the medium flows inside the seal and reduces the risk of leakage.

 

The sealing medium of the outflow mechanical seal flows from the outside to the inside. This sealing method has advantages in certain specific working conditions, such as situations where external media is required for cooling or lubrication.

 

4、 Classified by the balance state of the sealing end face

 

In unbalanced mechanical seals, the pressure of the medium has a significant impact on the specific pressure of the sealing end face. This sealing method may have a certain impact on the sealing performance in situations where the medium pressure fluctuates greatly.

 

Balanced mechanical seals are designed to minimize the impact of medium pressure on the specific pressure of the sealing end face, thereby improving the stability and reliability of the seal. This sealing method is suitable for occasions that require high sealing performance.

 

5、 Classify by other specific types

 

In rotary mechanical seals, the floating ring rotates along with the shaft. This sealing method is suitable for sealing situations that require rotation with the shaft.

 

In static mechanical seals, the floating ring does not rotate with the shaft. This sealing method is suitable for situations where the floating ring does not need to rotate.

 

PTFE bellows type mechanical seal uses PTFE as the bellows material, which has excellent corrosion resistance and high temperature resistance. This sealing method is suitable for sealing requirements in corrosive media and high-temperature environments.

 

Rubber bellows type mechanical seal uses rubber as the bellows material, which has good elasticity and sealing performance. This sealing method is suitable for sealing requirements under general working conditions.

 

According to the number and size of springs, mechanical seals can also be divided into large spring mechanical seals and small spring mechanical seals. Large spring mechanical seals have significant spring force and compensation capability, making them suitable for situations where the sealing surface is heavily worn; The small spring mechanical seal has a compact structure and is suitable for situations with limited space.