Packless Shaft Seal

Well.....it's that time again for Winter HaulOut
Am looking at installing the PYI-PSS Shaft Seal System.
Please share your experience and recommondation on this installation :nerd:
Thank ALL of you Enuts for your fine additions to our Honored Website

Happy HaulOuts

Had the PSS installed on my E29 a year ago and am very happy with it. Strange thing happened though when I had the impeller on my water pump recently replaced -- a sudden LOSS of water flow out of the exhaust. The mechanic ended up reducing the flow to the PSS with a smaller tube and that did the trick. Don't know why making the pump better (old impeller missing a vane) affected the balance of water flow to the PSS and exhaust. Maybe someone out there knows.

--Paul

Where is the missing vane. Did it partially block something or was it still in the pump when removed. I have had them block passages on larger inboards.

PSS Seal = popular topic

I am happy with mine for a decade. A picture is in this thread--
http://www.ericsonyachts.org/infoexchange/showthread.php?t=551&referrerid=28

If you use the "Search" button in the blue bar above these messages, and put in something like "PSS" or "packless seal" or the like and click on Go, you will find a lot of material to study and/or download.
There are many many threads with this in their title or with specific comments about this system within the thread.

Best,
Loren

My PSS, also installed in 1995, has provided similarly faithful service. It does bear inspection from time to time, but it is a lot easier to adjust than a flax packing.

EDIT: Wait, it's a Lasdrop shaft seal, not a PSS. I've since reconsidered this (March 2009) to the point at which I'm now about even on the benefits of a dripless seal vs. a traditional packing gland. I had a fuel leak which submerged the shaft seal in gasoline for a few days, possibly a week. The rubber bellows part of the seal was shot--fortunately (and miraculously) the boat was out of the water at the time. Had it been in the water it may well have sunk the boat. It was a pain in the neck to replace. Everything has to come apart--the coupling, the adjustment around the stern tube, etc. It's nevertheless a viable design, but it isn't head and shoulders above the simple old packing gland.

I've had the competition (LasDrop) on my E27 for around 15 years without any problems. I was going to put a new unit on a few years back, but LasDrop had changed their design and it was too long to fit now. Will probably go with the PSS someday (already overdue), which appears to fit.

Paul: Why do you have cooling water going to the PSS? I thought that was only required for power boats (high RPM).

Air, Water, and Liability

I'm not Paul, But I understand that the company got concerned about having their standard model being installed into (against their advice to the initial purchaser) use on a higher-speed hull and then being blamed for the subsequent problem or damage when the water was sucked out of the shaft alley. Because of higher speed usually associated with power boats, they always did sell a model with the potential to supply water into the bellows part.
I surmise that their lawyers convinced them to sell only the air-bleed model to better protect themselves from misguided lawsuits.

I have their standard displacement hull model, a decade old, with no air bleed fitting. Since we never go over 7 kts under power, we'll never have a problem. Their site now states that 12 knots is the threshold speed for this problem.

Also, with our model, you do have to remember to "burp" the bellows after relaunch to let out trapped air.

Here is the link to the install info at the PYI site:
http://www.pyiinc.com/index.php?section=pss_shaft_seal&action=instructions&sn=2

My .02 worth,

Loren

Anyone ever get one of these gemstones into an E-38 of the late eighties variety? I would love to put one in but I don't think there is enough room between the shaft coupling on the tranny and the shaft log where my existing stuffing box is.

Randy Rutledge said:

Where is the missing vane. Did it partially block something or was it still in the pump when removed. I have had them block passages on larger inboards.

Click to expand...

Good question. It wasn't in the pump housing so I guess its lurking somewhere in the Atomic like a thrombus waiting to become an embolism.

Yikes!!!

Paul

PSS in an E-38

http://www.ericsonyachts.org/infoexchange/showthread.php?t=3479&referrerid=28

This thread is about putting a PSS seal into a late model 38.
Looks like, from the commentary, that you could.....

Loren

I have the PSS installed without the airbleed hose. They will still sell it that way for a sail boat if you ask them nicely. It works great! Dry bilge and better speed at low rpm without the shaft friction that I had with old leaky (my worn out packing gland). I installed the PSS in 2004. They say to replace the bellows about every 5 or six years.

I looked into these for my E38 but I have decided against it. The standard packing was able to be adjusted to the point where I am satisfied and when it needs repacking I will use the Gore product as the PTFE material promises NO leaks and no compromises without the high cost of the PSS setup. Just my 2cents, RT

Air Bleed/Vent Hose

We put a PSS in this last summer. They no longer actively sell a fitting without the bleed line, probably for the reasons mentioned above. Interestingly, I had the yard install the PSS and they just put a plug where the bleed hose is supposed go. I asked them why they didn't run the vent hose. They said they didn't do it due to liability, figuring that some idiot would re-route the vent hose beneath the waterline, or accidentally cut it, likely resulting in the sinking of the boat. I subsequently ran the vent hose some place safe (not connected to the engine cooling system), and made sure it was labeled. Its not so much the initial burping I was worried about, but getting air in there if we happen to run into rough seas off the Washington shoreline next spring. I've also heard of air bubbles from divers getting trapped in the shaft seal.

- Cory

The problem with living in a very litigious society is that everything becomes the lowest common denominator of what it could be if everyone had accountability and common sense. On my PSS setup I have the carbon coller without the vent fitting. Also, the diameter of the hole in the fitting is 1 inch even though the prop shaft is 3/4". That arrangement allows a larger water volume around the shaft and less chance of a burn dry situation. Still, one should "spurt" the thing before taking the boat out if it has been sitting a while. Also, the 1" carbon collar on the 3/4" shaft seats better because it is surfing and not tight to the shaft.

Now, I can't tell you that anyone involved with the manufacture of the PSS system suggested anything to do with this set up. I can't tell you that people that do a lot of these for a living think this is a great way to set them up. I probably shouldn't even tell you that this works really great on my boat without adding the disclaimer that I have no idea what I am doing and that I am probably the product of married first cousins.

It is very likely that the people that sell the PSS system are required to sell only the units with the vent hole and it is probably the case that they must also tell you that you need to install the vent hose to keep your boat from sinking like the Titanic during one of your festive dinner parties off the east coast of Canada in early spring.

The vented system was really designed for power boats that motor at over twelve knots. In my opinion (that , of course being the opinion of an intellectually compromised cretin), a parted hose is a greater danger to the boat than a little air in the fitting. A quarter inch hose that is broken below the water line could actually sink the boat if it were left long enough and the bilge pump failed. I'm not sure what the potential for damage is with air inside the bellows. I have actually tried to run the boat with the bellows full of air and it always finds its way out before it heats up or I can bleed it off.

I think the PSS is a great alternative to a wet bilge. In the E35, the shaft seal is under a hatch right in the middle of the sole in front of the ladder, so it is really easy to inspect regularly.

I can't even begin to tell you what it means to me to no longer have the salty slosh puddle lurking under my engine. After I put in the new deisel to replace the atomic four that collapsed on it's rusty stanchions, I am done with the stoic and stodgy fortitude of a traditional packing gland. Just done, done I tell you.

Alternatives to Traditional Suffing Box

There has been much discussed in finding ways to the age old flax packing of the traditional stuffing box. We all hate to have water in the bilge and salty water spray in the engine room. There are many who wil never switch from the traditional set up. I am currently looking for a sensible alternative. The PSS setup leaves only the integrity of the belows material from stopping the ocean into your boat. I am not sure I could sleep soundly thinking about this.

Recently I found an Italian design setup based on an oil bath system to provide lubrication with seals to keep oil in and water out. It also incorporates a pump and an oil cooling coil. This design has been proven for years in Europe. Unfortuntaley, thus far it is not being distributed in the US. The system is made by Rexmar and is called the Hydraulic Seal, and has a nice and easy retrofit for DIY. It is expensive, about $500 plus shipping.

Another system is being offered by Seatorque in Stuart, FL. I saw this in the current issue of BOat/US magazine. I don't have a price on this yet, as I need to provide specifications on shfat diameter, length, etc. However, the system has the shaft encased in an oil tube. You could check website www.seatorque.com for more information.

Has anyone tried anyhting quite like these two alternatives to the PSS and traditional stuffing box?

Joe

OK,

I'm getting thoroughly confused on this nylon barbed fitting on the seal and the instruction pages don't seem to clear it up.

The yard installed one of these seals on my '84 E-28 (3/4" shaft) as part of some general engine compartment work I'm having done. Decided to spluge on this system since the tightness of the original stuffing box arrangment did not allow enough room to remove packing, only to squeeze in a little new packing. Also, with this boat's extremely shallow bilge, eliminating any water intrusion is a plus. Yard's dropping the engine back in this week but I'm wiring and plumbing it back up, including the addition of this barb.

Instructions seem to say it's OK to feed it water from the raw water circuit after the heat exchanger (where it's been warmed a bit by the closed loop system) and before injection into the exhaust elbow. My boat has an antisiphon loop before the exhaust water injection elbow which uses a 1/4" bleed line run aft to the transom where a small stream pees out while the engine is running. Perfect. Tap off that with a 1/4"-1/4"-3/8" reducing tee and run the 3/8" hose to the 3/8" fitting on the seal.

However, this board (and the manufacturer) indicates you don't even need this fitting for under 12 knots. Wish I knew before the yard ordered it that you can special order one without a hose fitting. I assumed that meant I could possibly cap off this fitting and not have to run extra hosing.

Checked with the manufacturer and laid out my plans and questions. Following is their response (quite a prompt response by the way).


Huh? :unsure: I've asked for a clarification. I assume the manufacturer knows what he's talking about but I worry about possible misunderstanding in our communication so looking for some feedback from Vikings with this system.

Wouldn't leaving this fitting open release water into the boat? I would think the two options would be either to pipe water to it or cap it off, not leave it open.

To Burp or To Vent

Note that the lawsuit-fearful vendor representative told you to leave the top of the *hose* on the vent open... This would be the hose on the barb fitting on the top of the PSS seal version that you have. This hose would have to be extended and well secured quite a bit above the waterline.

Since "trapping air" is only a potential problem in an installation where the boat goes over 12 kts under power, you do not have a problem in the first place, IMHO.

If you cannot get the PSS vendor guy to be candid and quit with the double-speak, just cap the fitting yourself. After you launch, burp the seal to expell any air trapped at the seal interface. This was exactly what they used to tell all of us displacement-hull customers a decade ago, and the advice should be as good as ever.

After our own recent haulout for replaceing the 11 year-old bellows on ours, I burped the seal and found that it was full of water from being launched and had no measurable amount of air. Of course, somewhere there might a sailboat with a very long shaft log at a significant up-angle, that might hold on to it's initial bubble of air, pre-burp. I guess. Maybe.

Loren in PDX
Olson 34 Fresh Air

Pss

Jim, apparently the yard did not give you all the paperwork that came with the seal kit. Put a length of 3/8 hose that is rated for below the water line onto the plastic barb fitting and route it up to where water will not enter the line on any angle of heel. The best place is as close to the center line of the boat as possible. Leave the top open to atmosphere, and it will allow any air bubbles that gather in the log to rise out. the pressure water hook up is for power boats that exceed 12 knots. Also, dont allow the weight of the hose to push down on the seal assembly. I just installed one on an E 38, and had one on my 30+, and will install one on my E 38 at next haulout. You can cap the bleed fitting, but you will need to burp it to let air out when you splash it, dive the bottom, or in exreme cases of rough going where air may get to the shaft log. Hope this helps, Harold, S/V MISCHIEF MAKER

The yard hasn't given me any paperwork on this seal. However, I thought the instructions on their website would be sufficient. Those instructions don't provide any options to cap or vent, just to supply water. Does the "dead tree" version (paper) of the instructions mention the vent hose option?

I see what you mean by the response from PSS. "keep the top of the vent hose open." I read that as keeping the barb open. Missed the subtlety of his mention of a hose. I see what you are referencing now.

I think I will go ahead and plumb it off a tee from the top of the gooseneck feeding the exhaust elbow. That does supply the water so I should never need to "burp" the seal. It's high enough to qualify as a vent (comes to the bottom of the inboard side of port seats), and is connected to the siphon break/bleed line that goes out the transom. That way, barring a hose rupture, any water from that seal goes overboard. And that bleed line provides a siphon break in case there is any backup of water from the shaft seal.

Thanks again for the insight.

Thought you would find this interesting. Of course the on-line installation manual makes no mention of a "vent" line, only a water feed line. However, between his responses and feedback from all you mighty Vikings , I've now got this figured out and will continue with my plan to feed the seal from the gooseneck.