Precautions for Mechanical Seal Installation

Author:Site Editor     Publish Time: 2020-09-02      Origin:Site

When installing

1. Be very careful to avoid installation deviations during installation

(1) The tightening of 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 a deflection. Check each point with a feeler gauge, and the error should not exceed 0.05 mm.

(2) Check the matching clearance (ie concentricity) between the gland and the outer diameter of the shaft or sleeve. The circumference should be even. Use a feeler gauge to check that the tolerance of each point is not more than 0.01 mm.

2. The compression of the spring should be carried out in accordance with the regulations, and no excessive or small phenomena are allowed, and the required error is 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. Too small will cause insufficient specific pressure and can not play a sealing role.

3. After the moving ring is installed, it should automatically spring back after pressing the moving ring to the spring.

Location requirements during installation

In order to ensure the stable operation, long life, and low leakage performance of the mechanical seal, it is very important to install it correctly on the machine. Things to pay attention to when installing:

1. Confirmation of parts

When installing the mechanical seal on the machine, make a good comparison with the general assembly drawing before installation to confirm whether the parts have been prepared. At this time, pay attention to whether there are any scars, defects, etc. on the seal friction surface, seal ring, etc. , also pay attention to whether there are any scars on the shaft or sleeve surface, flange, and other parts that are in contact with the packing, sealing ring (O ring), etc. If any abnormal phenomenon is found, it must be replaced or repaired before use.

In the actual installation, do not bring more parts than necessary to the site. In this way, if there are remaining parts after installation, there is a place missing during installation. If there are not enough parts, it means that unnecessary places are also assembled. After the parts are installed, this also serves as a self-check during installation.

(Some people think that a good assembler does not need drawings and other markings. This is wrong. Then he is just a skilled worker and not a good maintenance worker)

2. Installation location

Installation essentials vary with mechanical seal type and machine type. I won't repeat it here.

dual mechanical seal

Technical requirements during installation

The mechanical shaft seal is a mechanical part with higher precision, and its correct installation and operation have a great influence on its service life. We generally follow the standards set by the Ministry of Petroleum and Chemical Industry.

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

1. Shaft curvature: no more than 0.05 mm.

2. Rotor vibration: the vicinity of the shaft sleeve at the moving ring seal 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 shaft sleeve, no looseness of the shaft sleeve is allowed.

4. The alignment error of the coupling: For gear couplings, it is not more than 0.08~0.10 mm (P2008C), for elastic couplings, it is not more than 0.05~0.06 mm; (customary practice end jump<0.05, radial jump<0.10 )

5. The concentricity tolerance of the gland (stationary ring seat) and the seal fitting stopper to the shaft centerline is 0.05mm, and the perpendicularity value tolerance of the plane contacting the gasket to the centerline is 0.03~0.05mm, if it cannot be reached Requirements, the sealed cavity must be processed.

6. The end of the sleeve where the moving ring seal is installed and the end of the gland (or housing) where the static ring seal is installed should be chamfered and smoothed.

Besides, when installing mechanical seals, pay attention to:

1. Be careful when installing and disassembling mechanical shaft seals. Hand hammers and flat shovels are strictly prohibited to avoid damage to the sealing elements. If the fouling cannot be removed, it should be cleaned and then removed.

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

3. For the mechanical seal that has been in operation, if the gland is loose and the seal moves, the moving and static ring parts must be replaced, and should not be re-tightened for continued use. Because the original running trajectory of the friction pair will change after loosening, the sealing of the contact surface is easily damaged.

WenDong, as a mechanical seals supplier in China, provides professional mechanical seals knowledge and high-quality mechanical shaft seals. If you have any needs, please contact us now!


WenDong specializes in produce mechanical seals and custom mechanical seals solutions. By utilizing our extensive expertise, we can provide a complete solution to your challenge.

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