Can iso-mag seals handle any type of axial thrust? 1

[dawells]

I have a 800hp Westinghouse motor that was retro fitted with iso-mag seals, when run unloaded the magnetic center is thrusting the rotor towards the drive end seal. I was wondering if any one has used these types of seals and know if they can handle any amount of axial thrust. Any help would be appreciated

 

[ejc]

Iso-Mag does claim that their seal will handle axial motion. They capture the rotor inside the seal in an effort to keep it from moving too far from the magnetic force holding the seal together. However, I could not find a published maximum value that the seal will handle.
In my opinion, if the motion is excessive, the faces will separate to the point where the magnets will not push the faces together, and your bearing protection will be compromised. I would say that anything over 0.030" of motion is considered excessive for a bearing isolator. I would suggest contacting Iso-Mag for this maximum value.