The trub dam on our pick up tube is really quite effective!
Of course after your boil you'll want to set up a whirlpool to get a nice "cone" shape to your trub in the bottom of the kettle.
Our trub dam is a metal blade welded on to the pick up tube and fitted with a custom tooled (high temp / food grade) silicone gasket that seals the area under the trub dam "blade" and the bottom of the kettle itself. Thus keeping trub from sucking up into your pickup tube directly from the trub pile / cone in the middle of your kettle. For most of you - this is probably already intuitive and you "get it" ;)
No - the silicone won't "melt" or anything like that. The melting point of high temp food grade silicone like this is magnitudes higher than the boiling point or even the temp at the bottom of your kettle. You can google around to verify / validate that.
Here is a pic of the trub dam inside one of our kettles.
And NO we are not going to be selling the ball valve / trub dam as a separate assembly for use on other kettles. If you want one, you'll just have to spring for one of OUR kettles and craigslist /sell your current one! ;)