Venturi valve

admin

I was thinking today of making a venturi for my swimming pool pump, the idea being the flow would create movement and push water through a solar panel to extend the pool to all year use. Has anyone here made a venturi and if so is there a ratio on the small pipe size to the large pipe size?Clive
Reply:This may not be the type of venturi that you need, but I use these all the time. The size I use is 2" influent, 3" suction, and 3" discharge. I have never built these, but I have repaired them a lot ( brass keeps wearing through). Attached Images
Reply:Originally Posted by h2oboyThis may not be the type of venturi that you need, but I use these all the time. The size I use is 2" influent, 3" suction, and 3" discharge. I have never built these, but I have repaired them a lot ( brass keeps wearing through).
Reply:Originally Posted by WeldordiePlease help me understand the operation of this device.  Water is pumped into the inlet to develop suction that moves water into the suction pipe to circulate water.  If this is how it works, why not just use a pump to circulate the water?Thanks.
Reply:Venturis will not push, they can only pull. I don't know much about solar heaters, much less using a venturi to draw flow through it. And like said, venturis are usually used for gases. They will work with water, i.e. the little device you put on your faucet to drain a waterbed. But the problem is, they need a lower pressure on the discharge than on the suction.But you would be over complicating the situation. If you are just looking to get flow through a solar heater while circulating water, all you need is a bypass off your pump and push water through the heater while the pump still recircs the pool. No venturi needed. Heck, you could get real fancy and put a thermostatic control valve in there to regulate the outlet temp from the heater.Last edited by rat4spd; 12-02-2007 at 04:26 PM.
Reply:I met a guy who retired and moved to Tennessee. It was the first house he'd ever had with a basement and had heard horror stories about flooding.He wanted a sump pump that would be 'powered' by water.  The area he was in was prone to power outages during storms, according to teh neighbors. We found one and installed it but had a heck of a time convincing him that it had to drain into the floor drain. He wanted it to pump to the outside.The unit was a battery powered solinoid that opened a valve letting 'city water' flow through a venturi, sucking the water out of his sump.
Reply:I use venturi's all the time for water and fluidized solids. The way we operate this type is hook up the influent side with 55 PSI or greater ( more pressure more suction), then hook up the 3" suction side to whatever we need to pump, and then run the effluent where we need to. We sometimes have 10-15 PSI back pressure on the effluent, but we need a lot of influent PSI to work efficiently. The suction will pull a vacuum and suck the material out. The venturi pump is the most efficient way to drain water. We hook up a pump to a tank and pump in into the influent port of the venturi, then take the suction port of the venturi to the tank, and you have 2 pumps to suck out the tank.  The way the venturi works is it creates a suction by swirling the influent water.
Reply:Swirling the water?The way a venturi works for fluids is the increase in velocity of the fluid at the inlet nozzle causes a decrease in pressure. The faster the flow, the lower the pressure. Swirling (turbulence) is the very last thing you want. Airplanes generate lift the same way. The curve of the airfoil causes the air directly above it to gain velocity, lowering the pressure above the wing. At the same time the air below the wing is slowed a little, increasing pressure.Jeeez, I'm rambling now. No more Bud Lights for me. Miller EconotigCutmaster 38Yes ma'am, that IS a screwdriver in my pocket!