pss vs. pss pro shaft seals

[Papasail]

My boat of choice is IP 380, and they use pss shaft seals…. my curiosity is if it’s worth it to upgrade immediately after purchase to PSS PRO shaft seal. From a distance the Pro models seem superior, but real world results can sometimes yield different outcomes. My understanding is that shaft seals can fail more often than people would like to talk about.

Any experiences either way?

[SY Harmony]

For a sailboat, I don’t see an advantage to the PSSPro. If you’re concerned about the rotor walking up the shaft. Put a hose clamp on the inboard side of the rotor.

[slugsgomoo]

I've had a PSS seal installed for over 15 years now, and I've never had an issue with it, or a single drip. I do need to replace the bellows soon (normal maintenance), and it'd be interesting to find out if the pro bellows is compatible with what I have as I like the sturdier construction.

From looking at PYI's site, the cost difference between the two for my size is only $66, at which point I don't know that there's any reason not to buy the Pro... the biggest cost on the PSS is the haulout to install it in the first place.

I will say, I love the opportunity it presents in terms of a dry and dusty bilge, something that was never possible with the old stuffing box.

[wrwakefield]

Our sailboat had a Type A PSS installed by the previous owner around 2000.

With periodic bellows replacement (every 6 years recommended by manufacturer) the same unit is going strong despite ~75% use time of the boat since installation.

The stainless rotor has never slipped on the shaft, but I installed a shaft collar anode (because it is cheap and available) after it as a safety. (image appended)

If you drill and tap a couple of opposing holes in the collar anode parallel to the shaft, you have an easy bellows compression adjustment mechanism when the time comes.

The Pro version includes a SS safety collar, but I couldn't discern any other differences in the Pro vs. A models for my 1-3/4" shaft size.

I should mention the PO decided to feed raw water to the barbed fitting on the carbon stator even though my shaft speed (normally 900RPM) is well below the manufacturer specs for that requirement. I don't mind as it keeps the bellows and stern log flushed. I mention this in case it has contributed to the longevity of this installation.

In case any of this is useful.

Cheers, Bill

PS: I also replaced the (original?) nylon barbed fitting on the carbon stator with a SS version when the nylon one failed due to prolonged vibration.

PPS: The bellow does seem to take a set after being compressed for years, so I believe it is important to replace as recommended by PSS. (Photo appended of mine when changed in 2017; new bellow is on right with hose clamps. Note SS rotor is pitted. I reversed it to a new surface. Eventually, I will have a machine shop kiss both sides on a lathe to renew for a couple more decades...)

[Papasail]

The pics and literature I’ve read about the PSS Pro bellows, shows the original as made from nitrile (only), and the Pro version looking very industrial strength much like a rubber pulley belt, complete with fiber layers so it can’t tear or fall apart.

The info I saw on Youtube was older, but it looked very much like you could “upgrade” an older PSS system when it was time to refurbish it. The PSS Pro kit came with a secondary collar, almost exactly like your “anode” picture.

Good to know they’re way more solid (and dry) than I has thought!

[GreenWave]

I woudn't change a relatively new PSS seal to the Pro model. It shold be good for many years. You can consider switching when it needs replacement.