Dripless stuffing box vent tube location

[Project_Mayhem]

Where would you mount the tube for a PSS dripless seal? My options seem to be on the port side just below deck level or inside the galley cabinet closer to the centerline?

Port side: The port side is higher except for when healing. The head intake through hull is in this location. I love heeling so the rail does get buried sometimes

Galley cabinet: The sink will dip below the waterline on occasion in heavier waves. The sink has never overflowed so it seems to reason that just below the countertop would work

Waterline is approximately where the blue line is

I designed a crude catch can in the unlikely event that the vent tube overflows. It has an attachment for a drain tube.

 

[dlochner]

What's wrong with in the engine compartment above the waterline? That's where I've always located mine? In freshwater, there isn't a need for any catchment device, the only time water will back up through the hose is under reverse at a high rpm. Any water that gets through willl simply evaporate.

Or, get a Hy-Vent (amazon link). These work well. The PSS folks sell them too at a premium.

 

[Project_Mayhem]

The bottom of the sink in the countertop is below the waterline in heavy waves. I had water occasionally coming up the drain before in installed a check valve. The top of the engine compartment is at the waterline.

Do the HyVent's prevent air from escaping if the float valve inside is already floating? IE the waterline is above the device

 

[quadrille38]

What's wrong with in the engine compartment above the waterline? That's where I've always located mine? In freshwater, there ice, the only time water will back up through the hose is under reverse at a high rpm. Any water that gets through willl simply evaporate.

Well maybe.Thats where mine was originally installed. And every time the engine was put in reverse the water would shoot up at least a foot up out of the tube soaking everything including the engine and all the wiring in the engine compartment. There was no possible way that much water would evaporate.
The solution was to extend the vent up to a new through hull that was installed in the topsides just below the rub rail

 

[dlochner]

Do the HyVent's prevent air from escaping if the float valve inside is already floating? IE the waterline is above the device

It has to be above the waterline.

 

[Project_Mayhem]

Every potential spot inside dips below the waterline it seems. I can either mount it centerline 18" above standing waterline or on the port side of the hull 3' above standing waterline. I'm leaning more towards centerline.

 

[BAD ORCA]

You realize that the tube is optional on a sailboat? You dont have to use it if you can remember to 'burp' the bellows after you haul the boat. PSS sells a plug you can get that inserts into the hole for the tube. The tube was meant to help cool mostly power boats that travel at much higher speed than sailboats. They have stated in the past that its not required on a sailboat. They dont make this obvious though, so most people just install it thinking they have to.

Watch this video and you might change your mind about installing it.

 

[Rick D]

You realize that the tube is optional on a sailboat? You dont have to use it if you can remember to 'burp' the bellows after you haul the boat. PSS sells a plug you can get that inserts into the hole for the tube. The tube was meant to help cool mostly power boats that travel at much higher speed than sailboats. They have stated in the past that its not required on a sailboat. They dont make this obvious though, so most people just install it thinking they have to.

Watch this video and you might change your mind about installing it.

Correct. When I got a new one after 20 years on an old one, I asked about the plug. They responded that the vent was unnecessary on a sailboat and shipped mine with a plug. BTW, I don't know if it was necessary to install a new unit, but did so out of caution since the bellows was ready to be replaced anyway.

 

[FastOlson]

Where would you mount the tube for a PSS dripless seal? My options seem to be on the port side just below deck level or inside the galley cabinet closer to the centerline?

Short answer is that you do not need to use the tube. Back about 20 years ago or more, they sold two versions of the seal system, one for boats motoring under 12 knots, and a vented version for those motoring faster. The 'vented' version allowed water injection on boats motoring fast enough to suck the water out of the shaft alley; water has to be present to maintain the meniscus between the two surfaces that comprise the seal.
Rumor has it that their lawyers persuaded them to only sell one version to 1) save some $ in manufacturing, and forstall a potential claim against them if someone, after purchasing the non vented version, later used it (or sold it someone else using it) on a power boat.
As for "burping" the shaft alley after launch, this has always been a good idea, no matter what seals the stuffing box area. And, the need depends on the "down angle" of the engine shaft. If you read the install instructions for most diesels you'll notice that they do not advise a down angle of more than about 18 degrees , give or take. That's because of engine oiling considerations but also affects other things like maintaining water inside the shaft alley.
Some of us are lucky when we chose a boat with an engine installation that (almost) never has a problem with the alley staying wet. On our particular boat model, every time I have checked the PSS seal after a launch, it's full up of water right to the rotating seal. I have seen other sailboats, however, with the engine mounted at the max allowable down angle.
So, installing the tubing scheme is not "wrong," just not necessary unless you are on plane with your inboard V8 ski boat. Or, something similar...

 

[Project_Mayhem]

The low speed version that I bought has a hose barb

 

[dlochner]

The low speed version that I bought has a hose barb

For the past several years, maybe 10, the PSS has come with a hose barb. In addition @FastOlson's explanation there are 2 other reasons for using the vent even though it is not necessary on a sailboat. On some boats accessing the seal to burp it after launching is not an easy task. This was the case on my Sabre 30 which required dismantling some of the sail locker in order to reach the seal to burp it. Second, it is tempting to use a screwdriver or other device to burp the seal. Doing this can damage the graphite collar that bears against the SS collar to maintain the seal, a damaged graphite collar can leak.

 

[Project_Mayhem]

It seems that air will inevitably find its way in there at some point. It'd be nice to give it a way to escape without human intervention. One less thing to worry about in my eyes. I just need to figure out where to run the hose

 

[dlochner]

It seems that air will inevitably find its way in there at some point. It'd be nice to give it a way to escape without human intervention. One less thing to worry about in my eyes. I just need to figure out where to run the hose

At planing speeds, water in the stern tube will drain out that's why on power boats water is pumped into the stern tube to keep it lubricated. On sailboats, when the boat is hauled obviously the water drains out, however when launched air is trapped in the seal, which will cause the seal to over heat.

 

[JamesG161]

This how I did mine, after talking with PSS techs.

Good Luck...

Jim...

PS: Brass is protected by my shaft Zinc

 

[Project_Mayhem]

This how I did mine, after talking with PSS techs.

View attachment 236056

Good Luck...

Jim...

PS: Brass is protected by my shaft Zinc

This technique is what's listed in the manual for the pro version. Which one do you have?

 

[JamesG161]

Which one do you have?

Pro bellows with vent on top.

Jim...

 

[JamesG161]

More

Jim...

 

[jssailem]

If you're not going to run water through the nipple, then you just need to attach a hose (double clamps below the waterline) and run the hose vertically above the water line near the center of the boat. It is unlikely that you're going to subject your boat to a knockdown (lay her on her side with the mast touching the water). My calculations: measure from the nipple to the waterline in height. Then multiply that number by 2.5 (nipple to boat water line 12", multiply by 2.5, gives you a 30-inch hose that you run vertically), and you are more than safe. Hose is open to the air.

 

[smokey73]

I'm not sure I'd have the hose open to the air if the open end is somewhere water getting to this open end will drip or splash onto the engine or some other area where you don't want water. If you back down hard it is possible to force water into the bellows and seal and up the hose. I found this out the hard way when I noted corrosion around a particular area on my Yanmar right below the open hose. I installed the HyPoint vent and now have no such water intrusion.

 

[FastOlson]

I'm not sure I'd have the hose open to the air if the open end is somewhere water getting to this open end will drip or splash onto the engine or some other area where you don't want water. If you back down hard it is possible to force water into the bellows and seal and up the hose.

If... you are determined to have the hose in place, it seems like that vent hose could be led upwards to a little right-angle vent fitting at the upper part of the cockpit foot well. That area is generally above the engine shaft installation and way higher than the DWL.