Have the following part, BP-MBACET. I thought maybe it was stuck when I tried to blow through it, so I stuck something inside and it went through a white piece of plastic that seemed to have an adhesive. Turns out, that is all that was inside. Was there supposed to be something more? Thought maybe it would have had a metal plate and a spring.To me it looks more like an over pressure safety valve. And the white plastic was burst disk so to speak. If that is the case, I'm cool with that, but now I need a new white disk because I ruptured it.