Matters needing attention when installing mechanical seals! -Machinery Seal-

Matters needing attention when installing mechanical seals!

Precautions during installation

a. Pay great attention to avoid installation deviations during installation

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1) Tightening the gland should be carried out after the coupling is aligned, and the bolts should be evenly supported to prevent the end face of the gland from being skewed. Check each point with a feeler gauge, and the error should not be greater than 0.05 mm.

2) Check the matching clearance (ie concentricity) between the gland and the shaft or the outer diameter of the shaft sleeve, and it should be uniform around it. Use a feeler gauge to check that the tolerance at each point is not greater than 0.01 mm.

b. The amount of spring compression should be carried out according to the regulations, and it is not allowed to be too large or too small, and the error is required to be 2.00 mm. If it is too large, it will increase the specific pressure of the end face and accelerate the wear of the end face. If it is too small, the specific pressure will be insufficient and the sealing effect cannot be achieved.

c. After the moving ring is installed, it should spring back automatically after pressing the moving ring against the spring.

Location requirements for installation

In order to ensure stable operation, long life and low leakage performance of the mechanical seal, it is very important to install it correctly on the machine. Matters needing attention during installation:

1. Confirmation of parts

When installing the mechanical seal on the machine, it must be well compared with the general assembly drawing before installation to confirm whether the parts are ready. , and also pay attention to whether there are any scars on the shaft or shaft sleeve surface, flange and other components in contact with the packing, sealing ring (O ring), etc. If any abnormal phenomenon is found, it must be replaced or repaired before use.

During the actual installation, do not bring more than necessary parts to the site. In this way, if there are remaining parts after installation, there is a missing part during installation; if there are insufficient parts, it means that unnecessary parts are also assembled. Parts are installed, which also plays a role in self-checking during installation.

2. Installation location

The installation method varies with the type of mechanical seal and the type of machine. I won't go into details here.

Technical requirements for installation

The mechanical seal is a high-precision mechanical component, and its correct installation and operation have a great impact on its service life. We generally follow the standards set by the Ministry of Petrochemicals.

The technical requirements for the matching part of the pump with the mechanical seal and the mechanical seal are as follows:

1. Shaft curvature: the maximum is not more than 0.05 mm;

2. Rotor vibration: the vicinity of the shaft sleeve at the sealing ring of the moving ring is not more than 0.06 mm;

3. The axial movement of the shaft is not allowed to exceed±0.5 mm, if there is a bushing, the bushing is not allowed to be loose;

4. The alignment error of the coupling: not more than 0.08 ~ 0.10 mm for the gear coupling (P2008C), and not more than 0.05 ~ 0.06 mm for the elastic coupling;<0.05, radial jump<0.10)

5. The tolerance of the concentricity between the gland (static ring seat) and the sealing stop to the shaft center line is 0.05 mm, and the tolerance of the perpendicularity between the plane contacting the gasket and the center line is 0.03 to 0.05 mm. Requirements, the sealed cavity should be processed;

6. The end of the shaft sleeve on which the dynamic ring seal is installed, and the end of the gland (or shell) on which the static ring seal is installed should be chamfered and smoothed.

7. Be careful when installing and dismantling the mechanical seal, and it is strictly forbidden to use a hand hammer and a flat shovel to avoid damage to the sealing element. If the scale cannot be removed, it should be cleaned and then removed.

8. If mechanical seals are used at both ends of the pump, take care of each other during assembly and disassembly to prevent one from neglecting the other.

9. For the mechanical seal that has been used, if the gland is loose and the seal moves, the dynamic and static ring parts must be replaced, and should not be re-tightened to continue use. Because the original running track of the friction pair will change after loosening, the sealing performance of the contact surface is easily damaged.