Originally Posted by mtnguy
I think maybe the black thing-a-ma-jingie is an anti-siphon device.......but I don't know why a check valve wouldn't work.
Hi Chap, I did some investigation of the original BFP and what I found led me to believe why it would work as long as the water pressure was low:
This is a picture of the original BFP and all of its internal parts. And here is what I think was happening with the original one.
In the picture you can see the little piece of white plastic. That piece pushes into the BFP after the spring and ball are in place. What I found was that the little white plactic piece would come out of the BFP and slide into the water line where the collar nut was. This would allow for room for the spring to enter behind that plastic piece causing the ball to travel further then it was designed to. That's when ball would jump back and forth causing the water to bang and closing off the water supply. Then in my case if you would kink the hose line going into the trailer the ball would re-set. That's when I would release the kink slowly and would here the water cleaning the inside of the tank. Once I would release the kink compeltely the ball would start bouncing back and forth creating the banging sound and then seal in the closed position, thus allowing no water to enter into the tank.... Hope this all makes sense.
With the brass BFP all of its internal parts can't be removed so life is good...