I just got a proportioning valve from Ecklers. This is the first time i've seen one of these so I need to know if bought the right one. It's the brass type with the low pressure warning terminal. In the online pictures, on the end that is opposite from the large hex end there is something that looks like a black plastic plug or something, but the valve i got does not have this, it's just solid brass on that end. So my valve has 5 places to hook up lines to total. Is it supposed to have only 5? Can I still use this style?