PSS Shaft Seal problems

[chewi]

Just bought a boat with a PSS seal, I have no experience with this system. Looks like it takes a feed of pressurised water form the engine cooling pump.

That leaves me with a question. I winterise my engine in the usual manner, i.e. pulling the cooling hose off the inlet seacock, then sticking it in a bucket of water/antifreeze until the exhaust runs blue.

This technique will presumably pressurise the PSS with said antifreeze mixture. Will that then harm the materials in the unit, when left for 6 months over the winter?

I will be winterising afloat in marina so draining the seal isnt really an option.

thanks in advance!

Likely as not on a sailing boat ( Contessa I guess!) it is installed only as a vent, so the shaft water lubricates the PSS, not the cooling water, but that'd be easy to check, if not then prob wise to disconnect and make it safe while the Engine sits with its A/freeze and reverse when you recommission.

Only on faster boats do you need to feed it with the cooling water.

 

[Squeaky]

Good afternoon:

Doug 748: A disturbing tale, have you got in touch with the manufacturers?

No, I haven't because I have been so d**ned angry that I haven't been able to compose a polite message as their product was the cause of all the aggro I have had with this seal, never mind the expense which topped over 2,000 TL (divide by 2.21 for euros).

I noticed something someplace on this thread which seemed to indicate that someone from the company is a member of this forum and will probably read it. Personally I don't expect anything good to come from contacting them.

I will probably simply send them a link to this thread which was directed to fellow yachtsmen who had nothing to do with this incident therefore it was easy to write a reasonably straight forward post.

Cheers

Squeaky

 

[Old Troll]

PSS Shaft Seal

I have had the PSS shaft seal onboard now for 5 years without problem. However your photographs indicate that your shaft seal is not identical to the one I have installed. There were differing types being manufactured so please be carefull before condemning all dripless shaft seals.

 

[vyv_cox]

I have had the PSS shaft seal onboard now for 5 years without problem. However your photographs indicate that your shaft seal is not identical to the one I have installed. There were differing types being manufactured so please be carefull before condemning all dripless shaft seals.

I agree, there is something very odd here. The two hose clips on mine seat on the carbon block as might be expected, where they have now been for six to eight years, never any problem. The marks on the inner face of the failed one are surely not as manufactured? It would appear that there has been a fault of some sort. Have the faces been wetted out before launching? Does water rise up the hose?

 

[Squeaky]

Good morning:

vyv_cox The marks on the inner face of the failed one are surely not as manufactured? It would appear that there has been a fault of some sort. Have the faces been wetted out before launching? Does water rise up the hose?

I don't know if the faces were "wetted" out or not however if I remember correctly the water "feed" led from the exhaust so there should have been a steady stream of water to the unit.

I have no idea if water rose up the hose because it is just not something that I noticed and in any event don't see that either of these questions could have caused the split in the bellows. The problem, in both incidents, was that the bellows split near or under the clips - partly I am now sure because the carbon block to which they were clamped was not long enough.

The marks on the aft end of the block are very strange and not something that I would have expected from a properly manufactured item.

I am being to wonder if someone in Turkey is passing off Chinese "look alikes" as the real item. The original seal was retained by the man who installed it so he could claim a refund from his supplier in Istanbul so it is not available but I wouldn't be surprised if it was very similar to the second one I now have.

Cheers

Squeaky

 

[vyv_cox]

I have no idea if water rose up the hose because it is just not something that I noticed and in any event don't see that either of these questions could have caused the split in the bellows. The problem, in both incidents, was that the bellows split near or under the clips - partly I am now sure because the carbon block to which they were clamped was not long enough.

My reasoning is that I suspect that the split and the marks appear to be the result of high torque in the bellows. This can only be generated by a lack of water between the seal faces.

One of my inititial thoughts was that this might be a pirate copy. I have come across many roller bearings sold as being manufactured by the better companies, but which turned out to be pirates. Maybe PSS themselves know more?

 

[doug748]

I agree with Squeaky, that rough surface finish is not in keeping with the products I have seen.
I have taken the liberty of drawing this discussion to the attention of PSS. So we shall see, maybe.

 

[maxi]

30boat

Do please ignore 30boat's advice, as the specification for the Volvo seal is clear, in that it will NOT tolerate large movements or vibrations in the shaft, whereas the PSS normally manages these forces very well.

 

[RivalRedwing]

I agree, there is something very odd here. The two hose clips on mine seat on the carbon block as might be expected, where they have now been for six to eight years, never any problem. The marks on the inner face of the failed one are surely not as manufactured? It would appear that there has been a fault of some sort. Have the faces been wetted out before launching? Does water rise up the hose?

I have just had a look at a new PSS seal in my garage - the graphite tube extends well beyond the clamping area for both jubilee clips, the aft end of it has a smooth feel, much like the forward end that is visible. If I read your pictures correctly only the forward jubille clip is acting on the graphite tube + your picture of the aft end of the graphite tube does not look right, almost as if some filler has been applied to (unsuccessfully) remedy a break or failure of the tube. I've also not seen a rubber spacer between the bellows and the graphite tube before, I thought the supplier only used that option at the aft end of the bellows (but I'm sure they can advise)

 

[bert49uk]

I can confirm RivalRedwing post I have a new PPS seal under my bench waiting to be fitted this winter and there is plenty of meat under the clips

 

[fuss]

I can confirm RivalRedwing post I have a new PPS seal under my bench waiting to be fitted this winter and there is plenty of meat under the clips

I have a PSS seal that is about 8 years old and no problems. Bellows tension occasionally checked, still using original o-rings and grub screws. Oops... I know your not supposed to do that.

With mine, if I pull the bellows away from the stainless surface water comes in, but immediately stops once the bellows centers again on the stainless surface.
If a few weeks have passed since the last run then I always pull the bellows back to unstick the carbon surface from the stainless steel. If the carbon surface became stuck to the stainless surface then this would place a huge strain on the bellows once the propshaft began to turn.

When I look at the photos, it looks like the inner clip is not clamping down onto anything, which to me looks like there are some suspect parts. ie - not genuine.

With my limited experience ..... The seal is so well engineered that I could imagine that if you made a pigs ear of installing it, that within reason, it would still work fine.

 

[Squeaky]

Faulty PSS seal

Good morning:

I have decided that my PSS seal is either a fake or a faulty unit.

The more I look into this matter the more confused I become because:

A. the face which rotates against the rotator is cracked and it appears that a small triangular piece is about to flake offs - see 1st Photo.

B. There is a fairly large chip out of the carbon block - why and how? See 2nd photo.

C. What appears to be a rough area in the carbon block turns out to be some sort of material which is not part of the block as it could be scrapped away - almost like calcium scale. See photos 3 and 4.

D. It would seem that the long split in the bellows could only have been caused if one end or other was held stationary while the other end continued to turn. Obviously the end attached to the stern tube would be held firm which means that the end with the carbon block would have had to be stuck to the rotor. The face of the rotor is clean and smooth although the edges have been knocked about by the mechanic removing it. See Photo 5.

E. The carbon block is only 6 cm long which does not protrude into the bellows so the clips do not fully seat around the block - see photos 6 & 7.

F. Why was it necessary to have a rubber collar between the carbon block and the bellows - wouldn't it have made more sense for the clips to firmly clamp the bellows to the carbon block instead of clamping the bellows to another thin piece of rubber before clamping to the block? See photo 6.

G. The bellows, even with the rubber insert is now much larger than the carbon block which I am sure was not the case when new - Why??? See photo 8.

I have used the "contact us" form on the PYI (makers) web site twice in the past few days but not had any response from them. Is this a sign of disinterest or inefficiency on their part?

My suggestion to anyone considering purchasing one of this seals is to make sure that you are getting original items and that in particular that the carbon block is longer than the 6 cm shown above.

Will report back if and when I hear anything from the makers. I will also be checking with the shop I purchased this unit from to determine from whom he purchased it.

Cheers

Squeaky

 

[jfkal]

Looks Fake to me

Good morning:

I have decided that my PSS seal is either a fake or a faulty unit.

The more I look into this matter the more confused I become because:

A. the face which rotates against the rotator is cracked and it appears that a small triangular piece is about to flake offs - see 1st Photo.

B. There is a fairly large chip out of the carbon block - why and how? See 2nd photo.

C. What appears to be a rough area in the carbon block turns out to be some sort of material which is not part of the block as it could be scrapped away - almost like calcium scale. See photos 3 and 4.

D. It would seem that the long split in the bellows could only have been caused if one end or other was held stationary while the other end continued to turn. Obviously the end attached to the stern tube would be held firm which means that the end with the carbon block would have had to be stuck to the rotor. The face of the rotor is clean and smooth although the edges have been knocked about by the mechanic removing it. See Photo 5.

E. The carbon block is only 6 cm long which does not protrude into the bellows so the clips do not fully seat around the block - see photos 6 & 7.

F. Why was it necessary to have a rubber collar between the carbon block and the bellows - wouldn't it have made more sense for the clips to firmly clamp the bellows to the carbon block instead of clamping the bellows to another thin piece of rubber before clamping to the block? See photo 6.

G. The bellows, even with the rubber insert is now much larger than the carbon block which I am sure was not the case when new - Why??? See photo 8.

I have used the "contact us" form on the PYI (makers) web site twice in the past few days but not had any response from them. Is this a sign of disinterest or inefficiency on their part?

My suggestion to anyone considering purchasing one of this seals is to make sure that you are getting original items and that in particular that the carbon block is longer than the 6 cm shown above.

Will report back if and when I hear anything from the makers. I will also be checking with the shop I purchased this unit from to determine from whom he purchased it.

Cheers

Squeaky

What's on your photo does not even remotely resemble what an original PSS looks like.
It looks more like a soft rubber car part :-(

 

[Squeaky]

Good morning:

I have finally had a response from the European dealer which is more than can be said about PYI in America. These people seem interested and asked for the photos as they could not access the ones above (maybe not signed in?).

I have sent all the photos and expect to hear from them again soon.

In the meantime I don't want to damage the reputation of PYI and the PSS seal if the ones I were sold turn out to be fakes or something of that nature. If they turn out to be original the sky is the limit for the amount of damage I would like to do to their reputation but until proven, think it best to wait.

cheers

Squeaky

 

[Squeaky]

Failure to follow up after initial interest

Good morning:

As shown in my original post (number 39) I have had nothing but trouble with PSS seals purchased in Marmaris.

I contacted the European dealers who initally seemed interested in my problems however after forwarding additional photos and measurements they seem to have lost interest and I have heard nothing further although I have sent a hastener asking for further comments on the seals I was sold locally.

I strongly suggest that anyone interested in purchasing/using PSS seals should check the photos shown with my posts to ensure the seal in which they are interested or have is not similar to the ones I got as they are garbage in my opinion and experience.

The failures such as I experienced are not something to be taken lightly - had I left my boat after returning to the marina, I am sure I would have returned to find it on the bottom.

Cheers

Squeaky

 

[Squeaky]

Update on my problems with PSS seals Post 39

Good evening:

I think it is about time for an update on my problem which does not seem to be much closer to a resolution.

I forwarded the second seal to a company in France which I believe to be the European distributors who acknowledge receipt and said they needed to speak to the company from Istanbul which supplied the seal I purchased.

I have been told that the items are original but the seal was made up using incorrect sized items. This does not make much sense to me as it suggests that someone directed a minion along the lines of "hey, Mehmet, go out back and make up a 50 mm x 25 mm seal as some idiot from Marmaris has ordered one".

This implies that the various items are shipped in bulk to distributors in each country and made up/boxed to meet orders received. I doubt this as I am sure the seals are assembled much closer to the place where most of the items are manufactured - probably China these days.

I have sent a hastener to see if I can push this matter alone and will post the final response when I receive it.

Cheers

Squeaky

 

[Bosun Higgs]

Any further news? I am about to change seals from Volvo to PSS

 

[30boat]

Any further news? I am about to change seals from Volvo to PSS

In my opinion a Volvo seal is much safer than a PSS.I'd rather replace a worn shaft in order to fit a Volvo seal than use a face seal.

 

[Boo2]

So can anyone tell me where to get an old-fashioned bronze stuffing box that takes packing ? There seem to have been occasional issues with all the more modern seals and Sunrunner has a keel-stepped mast so never has perfectly dry bilges in any case : a few drops a minute more won't hurt.

Boo2

 

[sailorman]

So can anyone tell me where to get an old-fashioned bronze stuffing box that takes packing ? There seem to have been occasional issues with all the more modern seals and Sunrunner has a keel-stepped mast so never has perfectly dry bilges in any case : a few drops a minute more won't hurt.

Boo2

i have the original stuffing box, it does not leak or drip.
if you fit one it will be one of your better idea`s