Shaft seal Eliche Radice RMTA type

[pieter2]

This seal is simular to the Volvo seal. It comes with an attachement (nipple) for the water to enter. In my boat this seal is mounted and a hose is put on this water inlet nipple. This hose is directed to a higher point on the boat and that is all. So it looks like this hose is more acting like a deairing device instead of a water inlet.
Anyone familiar with this seal? There is nothing to be found about this water inlet on the website of the manufacturer, nor on the manual.

 

[vyv_cox]

It's on my website at http://coxengineering.co.uk/Sternglands.aspx What do you need to know?

 

[pieter2]

Great website!
Here you have a picture of my seal:
View attachment 12292
You see the hose from the waterinlet nipple. This hose is mounted to the highest point of the 'engineroom' with just an open end. So it acts like a de airing device. In the manual of Radice it says that this nipple is meant for waterinlet.
I am wondering whether this hose should not be connected to any watertank or something simular.

 

[Tranona]

No, its a vent to allow air to escape and water to come in, se removing the need to "burp" to clear air. The aft part of the seal is a waterr lubricated rubber bearing.

 

[pieter2]

Ok, Thanks. I guess I was misled by the manual, where is stated that it would be a water inlet
View attachment 12293

 

[vyv_cox]

My seal is a PSS but it has exactly the same layout, with a vent tube going above the water level. For my seal the water supply should be pressurised for higher speed motor boats but not necessary for sailing yachts.

 

[Tranona]

Ok, Thanks. I guess I was misled by the manual, where is stated that it would be a water inlet
View attachment 12293

You could use it as a water inlet with a bleed off the engine cooling system, but this would only be necessary on a high speed boat where there is a possibility of water being drained out of the stern tube. In yachts that is not an issue - there are thousands of unvented Volvos in use in yachts. The vent does, however, remove what is arguably one of the weaknesses of the Volvo seal - particularly if you dry out regularly.

The forward tapered part of the seal has moulded in two lip seals to stop water coming into the boat. These actually have little work to do, but need to be lubricated with grease from time to time because the shaft slides in and out as you go into gear. If the shaft is in good condition these seals should last indefinitely - mine (a Volvo) has been in the boat since 1995 and is still like new.

 

[pieter2]

Thanks a lot for all the answers! I am set at ease.