PSS shaft seal

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Joined: 10/6/20
Posts: 1
PSS shaft seal

I'm in the process of replacing the heat exchanger and hoses.   There's a Tee to the PSS dripless shaft seal.  This creates an annoying (and possibly dangerous?) siphon into the heat exchanger.  When I change the HE zinc, I always have to disconnect this line at the Tee and hold it straight up above the water line to break the siphon.  Is it really necessary to plumb this line to the PSS?  Wondering if I can eliminate the Tee.  A search here has yielded several different configurations.

The instructions say that under 12 kts, without a bearing in the tube it is not necessary.   I see 3 types of installs.
1) Tee'd to the HE like mine.
2) A hose just ran above the water line as a vent, some do it to a bottle
3) A plug in the shaft seal intead, with air bleeded when launched.

I'm thinking that option 3 sounds simple and safe.   No plumbing and the hole is plugged, no chance of a leak.  But I'm second guessing it since I believe this was done by a professional yard when the previous owner had it installed. 

Is just a plug acceptable for our boats?  Anybody with experience with this?  Or do I still need to add the Tee in the new hose?

Steve Shortt
1995 Catalina 36 mkII Hula Girl
St Petersburg, FL

Joined: 6/20/08
Posts: 201

We have a PSS seal in our boat with no Tee or hose. No problem.  It seems that those who do are always questioning how to route that line. Not worth it.

David S. Power
Two If By Sea #1687
Burnt Store Marina
Punta Gorda, FL

alfricke's picture
Joined: 4/14/09
Posts: 72

I've had PSS on two different boats (not Catalinas). No vent tube on either and no issues. The key is that anytime you haul the boat, on re-launching you have to make sure to "burp" it, getting the air out of the diaphragm. Very easy. I agree, that tube is a potential problem. 

Al Fricke
S/V Jubilee
Catalina 36' MkII  #1867

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