Frick 193 shaft seal

[NH3ISFORME]

We replaced the shaft seal on one of our Frick screws 193S TDSH RWB II. After putting it back together and running it over night more oil then before leaked from the seal. When not running ammonia leaks from the top area of the shaft. If we run the pre lube pump when the screw is not running oil starts oozing out from the bottom of the rotor. I think maybe alignment, clean up the assy. and reinstall again, thrust or end play, or just try to replace the seal again with a new one. Any suggestions?

[RANGER1]

Sounds like something is broken like carbon face on seal assy .
Take it out and have a look .

As for alignment , it should always be checked after replacing seal .

[McFranklin]

Why did the old seal fail? Rarely do the seals "just fail". The alignment, thrust clearance, and oil system needed to be checked the first time around, they most certainly need to be checked now. Yes, you could have a seal fail and then install a defective seal, but that's not normal. The overnight failure makes me lean toward an oil supply issue or massive contamimation from something (like a bearing cage breaking up). The 193 machine had plastic cage on the bearings that suffered early failure. It would then dump the pieces throughout the compressor. What does your oil analysis look like?

[CanadianIce]

It's possible that you may have torn the oring inside the rotating portion of the seal when it slid over the increased dimension part way up the shaft. The fix may be as simple as replacing an oring

C Ice

[Bart Nabbe]

Did you check the seal that came out?
If so, did it look the same as the one that is leaking now then you are sure it's not a sealproblem but something else in you compressor. Did you check the oilfilter for dirt?
Did you have vibration analyses on the compressor and motor? maybe your motor has a problem and damages the shaftseal with imballance.

Greets.

[Magoo]

Was the new seal assembly a factory supplied part or an after market supplier, I would be checking O/rings first and then compare the operating length of new seal compared to original. If old seal rotating carbon was chipped generaly indicates thrusting, Carbon gunge in area of carbon rotating is or could be alignment. If new seal is loosing oil at pre-lube definitely a damaged o/ring probably in the stationery face.

magoo

[Sleigher]

How does the shaft look?
I have two of those machines. One of our mechanics replaced the seal and it still leaked quite a bit of oil. I had another mechanic look at it (one with more experience) he reinstalled the seal but he first cleaned up the shaft with a fine emery cloth. No more problems.

Peter

[la461]

The most frequent cause of frick replacement seals is that the rotating element MUST be cleaned with an alcohol wipe to remove the protective film on the seal face. If it is not removed the seal will leak. In the new seal is a small piece of paper stating to clean the rotating element and it is usually discarded with out being read. Check the end play and if it is less than .003'' it is OK, .003-.005'' operate with caution and schedule a rebuild, and if it is over .005'' operate at your own peril. The compressor should be repaired immediately. We have been putting Parker o-ring lubricant on the inner o-ring on the rotating element and refrigeration oil and only use the oil the compressor uses to lubricate the mating surfaces. There are some who say to never lubricate the mating surfaces during assembly, but we always do and have only lost 2 seals in 3 years in our compressor rebuild shop averaging 45 Frick compressors a year.

[Grizzly]

There are some who say to never lubricate the mating surfaces during assembly

What idiot would suggest not lubricating a shaft seal.
Why not add some grinding paste to help bed the mating surfaces in!
Anyone who made that statement is a disgrace to our profession.
And more so does not understand how a Shaft seal works.
Sorry but that statement has made my blood boil!
Absolutely crazy
Grizzly

[la461]

I wondered when I was told not to lubricate the the mating surfaces, during assembly, that this guy was a few degrees off kilter. He was a pointy headed engineer and was trying to dazzle me with his great depths of knowledge. He went through some long winded explanation that bored me to tears.

[Grizzly]

I wondered when I was told not to lubricate the the mating surfaces, during assembly, that this guy was a few degrees off kilter. He was a pointy headed engineer and was trying to dazzle me with his great depths of knowledge. He went through some long winded explanation that bored me to tears.

Trust common sense, it invariably works.
The oil film between the 2 usually highly polished (optical grade) surfaces.
Is what forms the actual seal it's called a viscous seal.
Thats why seals can leak when having been sat still for long periods.
The oil film has dried out and why counting the frequency of the oil drips. From the seal into it's catch pot, is used as an indication of seal wear.
I hope this makes sense now as to why only an idiot would not pre-lubricate the surfaces.
Grizzly

[RANGER1]

Grizzly ,
I think it is the norm to lubricate shaft seals with refrigeration oil in refrigeration ... but over the years people who are extremely knowledgable in shaft seal companies have suggested we should put faces in dry , even to the extent '0' rings can be lubricated with liquid soap detergent or particular types of hand cleaner ( not abrasive types of course ) .

I tend to lubricate because it works for me .

[Grizzly]

Grizzly ,
I think it is the norm to lubricate shaft seals with refrigeration oil in refrigeration ... but over the years people who are extremely knowledgable in shaft seal companies have suggested we should put faces in dry , even to the extent '0' rings can be lubricated with liquid soap detergent or particular types of hand cleaner ( not abrasive types of course ) .

I tend to lubricate because it works for me .

I agree totally
As they say cleanliness and lubrication,
No-one has said but I was always taught that even the sweat from your fingers can be enough to cause a flaw in the seal faces.
I always use plenty of refrigerant oil as well,
"it works for me also".
Thanks Grizzly.