HOW TO ENSURE THE QUALITY OF MECHANICAL SEALS

A mechanical seal is a part that is good for rotating equipment. It is formed on one or more pairs of mechanical seal end faces which are straight to the rotation axis, and the fluid pressure and the elasticity of the compensating tissue maintain the attachment and relative sliding to prevent fluid leakage.

Mechanical equipment seal is also called end face seal, which usually refers to the seal used for pumps, compressors and other equipment rotating shafts. It is usually composed of the following components: 

the main components, including dynamic ring and static ring

 auxiliary seal, mainly refers to the sealing ring

spring force compensation mechanism, including springs and push rings

transmission parts, impeachment seat and key or various screws

Methods to ensure the quality of mechanical seals

The radial runout of the rotating shaft of the equipment shall be ≤ 0.04 mm, and the axial movement shall not be greater than 0.1 mm.

The sealing part of the equipment should be kept clean during installation, the sealing parts should be cleaned, and the sealing end face should be intact to prevent impurities and dust from being brought into the sealing part.

During the installation process, it is strictly forbidden to hit or knock, so as to avoid damage to the mechanical seal due to friction and seal failure.

During the installation, the surface in contact with the seal should be coated with a layer of clean mechanical oil so that it can be installed smoothly;

When installing the static ring gland, the screws must be evenly tightened to ensure the vertical requirements of the end face of the static ring and the axis line;

Pushing the moving ring by hand after installation can make the moving ring move flexibly on the shaft and have a certain elasticity;

After installation, the shaft should be moved by hand, and the shaft should not feel light or heavy;

The equipment must be filled with medium before operation to prevent dry friction and invalidate the seal.

Long life requirement of mechanical seal

To extend the life of a mechanical seal, its cover must be lubricated, cool, clean, and flattened at right angles to the bearing. The following points are required:

1. Good surroundings. When using the isolation fluid to clean, cool and lubricate the mechanical seal, the isolation fluid itself must be suitable, and the position of the isolation fluid must be higher than the fixed seal to ensure that the pressure is applied to the spring.

2. Assembly position should be precise. To measure the flatness of the mechanical cover using the wavelength of light, high-precision equipment is required. The instrument can only achieve high accuracy when it is manufactured. For example, the life of a pump's mechanical seal is much longer than the life of the seal installed in the pump on site.

3. Precision operation. At normal operating temperatures, the distance between the motor and the centerline of the pump must be accurate to within 0.05 mm. Due to some other external factors or human errors, when mechanical seals are not secure, all measures must be taken to keep the mechanical seal faces together.

How to ensure long life of mechanical seal

For the operator, pay attention to the problem of the pressure hammer and repair it in time. Keep the pressure of the isolation liquid higher than the pressure of the stuffing box, and ensure that the isolation liquid penetrates the sealing surface for maintenance.

For the maintenance person, the sealing surface should be cleaned regularly or the isolation liquid should be used, and the isolation liquid should be adjusted by the valve and the pressure difference. Align the shaft in perfect position during use.

Ningbo Haga Seals Industries Co., Ltd. is a specialist manufacturer of mechanical seals and seal material,such as Silicon Carbide Seal Ring, Tungsten Carbide Seal Ring, Alumina Ceramic Seal Ring, O Ring,etc..

Now our products are well popular in America, southeast Asia, mid-Asia and so on, our customers are satisfied with our competitive price, superior quality.