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What Should We Pay Attention To When Installing Cartridge Mechanical Seal?
May 12, 2018

What should we pay attention to when installing cartridge mechanical seals?

1, to pay great attention to avoid the installation of the installation deviation

(1) The tight packing should be performed after the coupling is aligned. The bolts should be evenly supported to prevent the cover from deflecting. Check the points with a feeler gauge with an error of no more than 0.05 mm.

(2) Check the gap (ie concentricity) between the gland and the outer diameter of the shaft or bushing. The circumference should be uniform. Check the tolerance of each point with the feeler gauge is not more than 0.01 mm.

2, the amount of spring compression should be carried out according to regulations, does not allow too much or too small phenomenon, requires an error of 2.00 mm. Over the General Assembly to increase the end face pressure, accelerate the end wear. Too small will cause insufficient specific pressure and can not play a sealing role.

3. After the ring is installed, it should be able to spring back automatically after the ring is pressed against the spring.

Mechanical seal installation.jpg

Position requirements at 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 the mechanical seal is installed on the machine, it must be compared with the general assembly drawing well before installation to confirm whether the part is ready. At this time, it is necessary to pay attention to the abnormal phenomenon such as the sealing friction surface and the seal ring, whether there are any flaws or defects. Also, be sure to check the presence of fillers, seals (O-rings), etc., on shaft or bushing surfaces, flanges, and other parts for signs of damage. If abnormalities are found, replace them or repair them before use.

In the actual installation, do not bring more than necessary parts to the site, so that if the remaining parts after installation is complete, it is a place where there is a missing installation; if the parts are insufficient, it means that the unnecessary places are also assembled. On the part, this also plays the role of self-test at the time of installation.

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

2, the installation position

The installation method differs depending on the type of mechanical seal and the type of machine. I will not repeat them here.

Technical requirements at the time of installation

Mechanical seals are high-precision mechanical components, and their correct installation and operation have a great influence on their service life. We generally follow the standards set by the Ministry of Petroleum and Chemical Industry.

The technical requirements for fitting the mechanical seal to the mechanical seal are as follows:

1. Shaft bending degree: the maximum is less than 0.05mm;

2, the rotor oscillation: the ring around the ring seal ring is not greater than 0.06 mm;

3, the axis of the shaft does not allow more than ± 0.5 mm, if the shaft sleeve, does not allow loose shaft;

4. Coupling alignment error: not more than 0.08-0.10 mm (P2008C) for the gear coupling and not more than 0.05-0.06 mm for the elastic coupling; (according to the practice, end jump <0.05, jump <0.10 )

5. The tolerance of the concentricity tolerance between the gland (static ring seat) and the seal-fitting stopper on the centerline of the shaft is 0.05mm, and the perpendicularity of the plane contacting the gasket to the centerline is 0.03-0.05mm, if it fails to reach Requirements, sealed cavity to be processed;

6. Install the end of the bushing of the dynamic ring seal ring, and the end of the gland (or the housing) where the ring seal is installed should be chamfered and smoothed.

1. Be careful when installing or removing the mechanical seal. Do not use the hand hammer and flat spade to avoid damage to the sealing element. If scaling does not remove, clean it and remove it.

2. If mechanical seals are used on both ends of the pump, take care of each other in the process of assembly and disassembly, so as not to lose sight of one another.

3. For mechanical seals that have been operated, where the glands are loosened and the seals move, the moving and stationary ring parts must be replaced and should not be used again. Because loosening the original friction trajectory will change, the contact surface of the seal is easily destroyed.