Originally Posted by macwester26
I intend to use a dedicated sea **** just to supply the raw water to the pss seal or another type of seal.
Just a strait forward sea **** with a grp ( home made ) water scoop fitted to the outside of the fitting.
So even when the engine is NOT running just sailing along will still permit water to go through the fitting.
You probably don't need to go to such lengths. It is pretty simple. The water flows up the stern tube by gravity, into the bellows and bathes the inside of the carbon seal. This is enough to lubricate and cool the seal, which generates almost no friction. The only reason for the tube is to allow any air that might get trapped in the bellows to escape. This tube was not on earlier models as I understand. No seacock, scoop, or dedicated pump necessary.
Here is a picture of mine before I put the tube on. The tube just goes up vertically about two feet where it is secured with two cable ties to an existing bracket. And that's all you need.