Dudester
10/14/2007, 01:54 AM
I just got a brand new RD 6.5 and rigged it up to match standard plumbing fittings.
http://i16.photobucket.com/albums/b27/mjosephs/179g%20rimless/reddragonplumbed3.jpg
It runs fine all by itself and when placed in a large basin, but when I plumb it into my sump it seems to cavitate. Initially I just thought it was sucking so hard that air was being drawn from the top of the water. So I filled the sump higher (it's plumbed internally) but this didn't solve the problem. The pump has bidirectional flow through the intake! I placed an elbow facing down over the intake and that solved the problem temporarily. When I dialed the flow of the pump down with a ball valve plumbed on the outlet, the problem returned immediately. Does anyone know what this is all about? Also, is there a problem dialing down the flow with these RD pumps? There is no ball valve on the intake; the intake is free of any plumbing or connections. When there's no fitting on it, it seems to run with bidirectional flow, sucking in water and squirting out water from the intake at the same time. Weird!! When I apply an albow, this stops the bidirectional flow. Then, when I dial down the ball valve that's placed on the outlet, the bidirectional flow returns. Is this a pump problem and if not, what's the cure?
http://i16.photobucket.com/albums/b27/mjosephs/179g%20rimless/reddragonplumbed3.jpg
It runs fine all by itself and when placed in a large basin, but when I plumb it into my sump it seems to cavitate. Initially I just thought it was sucking so hard that air was being drawn from the top of the water. So I filled the sump higher (it's plumbed internally) but this didn't solve the problem. The pump has bidirectional flow through the intake! I placed an elbow facing down over the intake and that solved the problem temporarily. When I dialed the flow of the pump down with a ball valve plumbed on the outlet, the problem returned immediately. Does anyone know what this is all about? Also, is there a problem dialing down the flow with these RD pumps? There is no ball valve on the intake; the intake is free of any plumbing or connections. When there's no fitting on it, it seems to run with bidirectional flow, sucking in water and squirting out water from the intake at the same time. Weird!! When I apply an albow, this stops the bidirectional flow. Then, when I dial down the ball valve that's placed on the outlet, the bidirectional flow returns. Is this a pump problem and if not, what's the cure?