The amount of wear of the mechanical seal-

The amount of wear of the mechanical seal

　2017-07-19　　

Abrasion of mechanical seal:

In the mixed friction state, there is friction and wear between the end faces of the contact mechanical seal, and the life of the mechanical seal under normal conditions mainly depends on the wear of the sealing surface. The degree of wear can be expressed by wear rate and wear coefficient.

The wear rate is the amount of wear per unit time, expressed by γ. According to the knowledge introduced in tribology and sealing technology of MG12 mechanical seal, the amount of abrasion due to the adhesive wear of the friction pair material is

Wear coefficient can be used to get the wear rate. , The available wear rate is

ie

In this way, the known value can be used to obtain the wear rate.

JB4127.1-1999 'Technical Conditions of Mechanical Seals' stipulates that the amount of wear must meet the requirements of the service life of the mechanical seal. When the test is performed with clean water as the medium, the amount of wear of the seal ring of soft material for 100h is not large. 0.02mm down. That is, the wear rate

The wear coefficient is a dimensionless number. The smaller the value, the less wear. It is usually measured by wear test. The wear coefficient of some mechanical seal sealing surface materials is shown in Table 1-14.

Table 1-14 The wear coefficient of some mechanical seal sealing surface materials

Table I-15~Table 1-18 list the value, specific wear rate and wear coefficient of some mechanical seal surface materials when they are matched.

It can be seen from formula (1-22) that to calculate the wear rate of the sealing surface, in addition to the selection of the wear coefficient, the ***** value of the mechanical seal must be calculated in advance. Only in this way can the wear rate of the mechanical seal be accurately calculated γ. Let me cite a few examples. In order to facilitate the comparative analysis, the relevant data of the sample questions and the solution are shown in Table 1-19.

Table 1 -15 Wear data of resin-impregnated carbon graphite at different temperatures and different material combinations (water)

Table 1 -16 Wear data of the combination of carbon graphite and ceramics immersed in Babbitt alloy (water)

Table 1-17 Wear data of resin-impregnated carbon graphite and ceramic combination (water)

Table 1-18 Wear data of the combination of carbon graphite and tungsten carbide immersion bronze (water)

Example 1 ~ 1 Table 1 -19 Calculation example of seal wear

Continued

Analysis from the calculation results:

Example 1 The diesel pump is sealed, so the seal can run wet for more than 15000h. Due to the lack of a good lubricating medium, the dry operation is only 3955h, which fails to meet the specified requirements.

Example 4 The value of the seal for the propane propylene pump and the wear rate is greater than the specified wear rate. Because the seal is a gas-phase seal, only 6330h does not reach 9000h in dry operation; and because its wear rate is greater than the specified value, the seal operating life cannot meet the specified requirements.

Except for Example 1 and Example 4, the other examples are worthy because of the relatively large bearing capacity of the fluid film. If all are designed according to the wet running state, the value and the wear rate are all less than the specified value, and the wet running life is more than 15000h.　　538.html,

The friction coefficient of the mechanical seal 　 　 the leakage of the mechanical seal