The PSS seal only requires a vent and doesn't need burping.
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Thread: Shaft seal water feed
23-02-12, 12:41 #11
23-02-12, 12:43 #12
The Radice seal is now easily available in the UK. It can be used with a vent for slower craft rather than force fed. It has the advantages of a Volvo seal without the need to burp.
23-02-12, 12:49 #13
Thanks for the suggestion, the Volvo seal was my first choice, but having a 1" shaft and 1 1/2" tube means none of them are even close to fitting
I was surprised by it as well so I checked on their own website, in the fiting instructions it details the need for 4L/min flow and in the knowledgebase it says...
"Some owners are tempted to forgo the water injection system on vessels such as these displacement hulls rather than planning hulls. In most cases, the column-head of pressure moving up the shaft is sufficient to keep the lip seal interface cool and the bearing lubricated. However, depending upon the efficiency of the propeller and its proximity to the propeller shaft through-hull, the Tides shaft seals can be deprived of necessary water. For this reason, Tides always insists that the water injection system be used to prevent potential problems of any kind."
I think the alternative with a breather is the Radice seal, looks like a bulkier Volvo seal with a vent tube. I was also interested in that but haven't heard anything from anyone who owns one and I because of my inexperience I like to buy based on reviews.
There's the PSS that can be vented and has good reviews, but that just turns this thread in to another lip/face debate so perhaps better not go there
23-02-12, 12:55 #14
23-02-12, 13:02 #15
So we have Radice and PSS that can both be vented without forced cooling.
Can anyone tell me the distance between stern tube and the bit of a PSS that sits on the shaft? Potentially if it is longer than my old seal I won't need to replace the shaft as it will sit on an unworn bit which would be a nice saving
Where in the UK can the Radice seals be bought from?
23-02-12, 13:06 #16Registered User
Location : me Bristol, boat Plymouth
- Join Date
- Nov 2010
It is worth bearing in mind that when sailing and the shaft free to rotate there will be no forced waterfeed to the shaft seal whereas with the vented system water is always present on "slow" moving craft.
Maybe my Tides Marine shaft seal works while vented is because I have a relatively large clearance between shaft and tube allowing for good water access.
23-02-12, 13:15 #17
If this is the case it's a pain they don't just say that as my tube is free of obstructions and a good distance from the prop with a P bracket between.
23-02-12, 13:34 #18
23-02-12, 13:53 #19Registered User
- Join Date
- Nov 2007
BTW I have used a Volvo seal for over 10 years and the burping and greasing is really not a problem unless you are on a drying mooring. It soon lets you know if you forget burping as the dry rubber bearing part makes a horrible noise!
23-02-12, 16:03 #20
I asked the question of Tides Marine about the need for positive water feed, and all credit to their service I got a proper reply from Brian Raine at Tides Marine within 1 1/2 hours to explain, which is absolutely exceptional for responding to email queries in my experience.
He has said (paraphraseing) that although they ask for 4L/min, the seal only allows about 2L/min, they ask for 4 to make sure it is under pressure.
He also said that vented installations can let marine debris build up inside the seal which causes alignment issues with the bearing and lip which is why they insist on the pressure feed to prevent this.
Now I know why they want it, I'm still not happy about hacking into the coolant though.