Greetings to all ---

Been a while since I have been on this board. As those of you from the Joe Peterson days recall, i used to haunt these boards, but I have a REAL job now......

Anyhow, saw one last week that just blew my mind. Classical liquid ring vacuum pump with center motor and pump on each end as is common in paper mills. This one was vibrating, OB end of one pump had hot bearing, etc.

Mill had a number of pumps/motors set up this way. Center motor open frame motor, liquid ring vacuum pump on either end, with SPACER COUPLINGS between motor and vacuum pump. They were of course gear couplings.......except this one......

Made 'em take the coupling guard loose, and lo and behold, they had a steelflex on the motor end, spool piece in between, and gear coupling on the pump end. All were Falks.........

And they were OFFENDED when I explained the error of their ways to them......said the Falk guy said it would be alright.......

Comments ????

And you know what, now that I think of it, I have NEVER seen steelflexes used in a spacer application, and can think of a lot reasons why you shouldn't.....

Anybody else seen anything like this....????

For those like me who are not very familiar with spacer couplings, can you explain why that setup is bad?

The flex steel couplings will take more offset alignment and less angular than the gear couplings of the same size. The opposite is true for the gear couplings. Some Falk flex steel couplings may have a spacer shaft as the other half of it.

The issue here is that the alignment between the motor and the pump will be driven by the coupling that will take the least amount of angular and offset misalignment.

The offset will be determined by the gear coupling and angular by the flex steel.
If the gear coupling is a limited end float then there is an longitudinal alignment parameter as well.

Do they know this?