Experts, please help me figure out how to remove this type of mechanical seal

Single-stage double-suction pumps are troublesome; they can only be taken apart completely.

Is it necessary to first remove the bearing housing, then take off the shaft sleeve, pull out the moving ring, measure the compression amount again, and then reinstall it?

Replacing the mechanical seals on both sides of the impeller is a considerable task – you need to remove most of the components on the shaft except for the impeller itself; only those parts that are small enough to pass through the mechanical seals can be kept, as long as the seals can still open and close

Just replace those that are not on the shaft coupling: remove the bearing housing, take out the bearings, install the shaft sleeves, replace the stationary and rotating rings, measure the compression amount, and then reinstall everything. That’s probably the correct sequence, right?

If it is smaller than the size of the inner ring of the seal and does not cause any issues, there is no need to remove it; decide for yourself what needs to be taken off. After all, the goal is to allow the seal to be replaced without any obstacles in terms of access

For a single-stage, double-suction, double-support centrifugal pump, it’s simple to replace just the O-ring. However, if the entire seal set needs to be replaced, then the bearings and shaft sleeves behind the seal must be removed in order to install the stationary and rotating rings of the seal.

Yeah, it’s quick to remove the shaft sleeve as well. Fortunately, there’s no need to measure the total compression again; just measure it at the position of the bearing using the original rotating ring, and then reinstall it, right?

The last edit to this post was made by Little universe de Smile on 2017-7-24 at 22:14. You need to check whether the new seal is original, and whether the dimensions of the static ring, dynamic ring, dynamic ring seat, and springs are the same as those of the original seal, as these dimensions affect the degree of compression. Even for an original seal, since it is not a pre-assembled seal, the degree of compression still needs to be measured again during installation; adjustments may be necessary if it is not appropriate. However, in pumps with a horizontally split pump body of this type, it is easy to measure and adjust the compression amount of the mechanical seal, as the stationary and rotating rings as well as the springs are visible, allowing for easy measurement using a depth gauge or a ruler. We have repaired similar pumps before; the type of mechanical seal is the same. The new seals are not original, and there are significant changes in the dimensions of the stationary and rotating rings as well as the springs. The compression amount has also been readjusted. As a precaution, the compression amount of non-integrated seals must be measured again, and if there are issues with it, it needs to be adjusted once more.

I took a look at the drawings; in this design, the shaft sleeve sits directly on top of the impeller. If I only want to replace one end of the mechanical seal, do I need to lift the rotor? Can the shaft sleeve along with the rotating ring be taken out by simply removing the bearing housing?

Send the drawings over for a look. Can the bearing housing be removed as a whole? If the rotor isn’t lifted, how can the bearings be taken out? Even if they can be removed, after taking out the bearings on the non-driving side, the rotor will inevitably sink towards that side; it’s also necessary to consider how to keep the rotor level, otherwise how can the bearings be reinstalled?