RB199,
I did not say that i knew what they were !!!!
read the post ....i put ??? after fuel dump valves thereby stating a question....!!!
I've been around aircraft long enough not to try and infer i know everthing....hence why i queried it too as i geuinely did not know what they were....
One thing i have never been afraid of is to ask advice if im unsure, as in this case...!!