Shaft / Seal temp

[webber63]

Hi everybody,
I have just replaced the old packing gland with a Radice RMTA dripless shaft seal (a reengineering of the Volvo Shaft Seal).

The seal has a hose connector that should be used, as the datasheet says, for lubrication water inlet.

The stern tube and the seal are well under the flotation level and the flow of water, removing the seal, is plentiful.

After reading several advices on this and other forums I connected a hose without connecting it to a pressurized water source, but taking it well over the floating level and leaving it open as a vent because the low speed of a sailboat, I read, should not create issues in water flow.

After going out for a test of 30-40 minutes at cruise revs (2200 RPM, the engine is a Bukh DV20) I returned in port and, after mooring, I checked the seal touching the seal itself and the shaft.

The seal is almost cold (the atmosphere temp was about 18°C)- just warm, the shaft a little more warm, not hot (can be touched without pain).

Is it normal or have I to worry about?

Thanks for your replies

 

[Tranona]

Nothing to worry about. The vent ensures that there is no air in the seal, but you can check by squeezing the end and where should squirt out.

 

[Vronsky]

Dear All,
I have installed a very similar dripless seal (TOR Marine) recently. Using a laser temperature meter, I'm measuring a shaft temperature during operation of 40-50 degrees Celcius.
The product info of the Radice seal specifies an approved temp range of -10 to +80 degrees C.
I have no such document on the TOR brand seal.

I tend to believe that both seals are very similar however incl. the rubber performance.
Would you agree, and that the operating temp of my prop shaft is fine ?

Best Regards,
V.

 

[macd]

just warm, the shaft a little more warm, not hot (can be touched without pain).

Is it normal or have I to worry about?

Perfectly normal, cross it off your list of things to worry about.
As Tranona implies, a pressurised water feed is not required on a sailing yacht installation.
I presume it came with a little tube of silicone grease and that you've used some?

 

[Pye_End]

If you want to check that water is getting into the seal then give the vent pipe a suck and see if the level comes up.

 

[Vronsky]

I used a bicycle pump to clear the stern tube of old grease from the previous packed stern gland, and noticed a lot of bubbling and flakes of grease from under the hull. Water level in the hose is equal to the outside water, and each time after releasing the air pressure the water came back instantly, so the outside water seems to reach the seal properly. Little grease container is full.

Could it perhaps be that the shaft temp will drop once the lip seals are settled in ??