Frick Seal failure

[Drizink43]

Couple quick questions, We have RWF 316E Frick screws for our ammonia refrigeration. I've just started with the company this year and have inherited (4) 600hp units with chronic shaft seal problems and a system plagued with issues. So Im learning and attacking these one at a time. First question is does anyone have a general life expenctancy of a shaft seal? Does anyone have any background knowledge of these machines that may help lead to a solution, cause apparently our main service vendor has been working on this for some time and the people before me just throwing money at the problem, Id rather pay for a solution. Any thoughts? Any and all help is greatly appreciated!

[Magoo]

Start by getting couplings Lazer aligned. Then the oil compatabilty with the o/ring materials in seals. Check the thrusting tolerances. Are the new seals factory supplied replacements or local re-build repairs, if the later perhaps the wrong carbon quality for application.

[Drizink43]

The seals are factory supplied,my Frick contractor has brought the issues to Frick directly and after much waiting, Frick has come back with a different style seal. I haven't seen the new seal yet but I will be sure to update with details. I will also check into the alignment of the couplings and the procedure that the contractor follows. Its funny you should mention the oil. We have been monitoring an issue of high iron content in our oil. Prior to my arrival, the company had changed the oil in all four compressors and the iron content remained, although it has not gotten worse, it hasn't gotten better either.

[RANGER1]

Iron does'nt sound promising , how old are they & what servicing has been done in the way of overhauls etc .

If shaft seals are being replaced maybe a thrust bearing check in order regardless .

[McFranklin]

A vibration analysis might give you some more information. It would certainly reveal pending bearing failure in either the compressor or the motor.
Are you using a Frick oil?
In one of the other threads Howden had some issues with the formulation in certain oils decreasing seal life.
What micron rating are you using on your oil filters?
What are the operating conditions? Are you pushing the limits of the machines?
But you have four machines that are suffering short seal life and "a system plagued with issues" which leads me to think it might be something other than the compressors.
Are the vessels sized to prevent liquid carryover?
Are the high level controls in proper working order?
The statement about finally offering a different seal configuration tells me that it isn't an inherent problem with the compressor package. A system problem maybe?
How are you using the economizer ports?