Can you ask your dad what safety valve he recomends? I've watched many of his videos and remember him commenting on how he didnt like the sound of some safety valves. I'd like something that pops open and closed rather than the valves that buzz and make an aweful noise.
Well I wasted my money on a safety valve. It looks great and I'm sure it'll work just fine but after testing it with air, it turns out to be the type of safety valve that makes the buzzing noise instead of a pop type valve. Time to keep looking.