Converted keg kettle

[sdbrew1024]

Today I acquired a converted keg with a ball valve for a boil kettle. The ball valve is simply screwed into a hole in the keg with a rubber o-ring on the inside and outside. Is the rubber anything I should worry about here? Any better alternatives?

 

[BargainFittings]

If its silicone then you will be fine. Buna-N (generally black) o-rings have a lower melting point but will hold up too.

Don't dry fire your kettle and the orings will not be a problem.

 

[BrewBeemer]

Take a look at this chart;
http://www.oringsusa.com/html/temperature_range_of_o-rings.html