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Step 2Build a better gate valve!
All the available plans for ram pump valves are based on converting a conventional foot valve to operate in reverse. The trouble with this solution is you end up with a valve that is flimsy, wobbly and unreliable. It works, but it wears out too fast and jams up too much. My design takes care of it by starting from scratch and making it strong. My wife says I am strong like bull and smart like tree so I make everything I build that way. I also like to use whatever I have around the farm so that is exactly what I did. You could build it prettier and simpler, but recycling scrap is a priority around these parts, especially if you are broker than the ten commandments... This project really paid off for us, it just works great.
You need the picture of all the valve parts to see that it's easier to build than than it sounds below...so let's GO...
I had a 2" to 1.5" copper reducer with a short piece of 1.5" pipe attached and that makes the valve body. I also had a 6" brass tail stock sink connector that I inverted and soldered inside the reducer because that had a nice smooth lip that makes a perfect valve seal with no work at all. If you have a new reducer and smooth it off with sand paper, you likely don't need the tail stock step. Now drill a 3/4" hole all the way through the pipe just above the reducer and smooth the edges and presto, your exhaust port is all done.
Next problem... how to replace the O ring seal used in converted foot valves. It routinely wears out or slips out of place and stops your pump. So, let's not fool around. Take a hockey puck and use a hole saw to make it 1.85 " in diameter so it fits inside the 2" reducer and has lots of clearance around the outside. Drill a 1/2" inch hole exactly in the center and put a bolt and nut on it so you can hold it in your drill press. Then spin it with a file against the edge so you get a nice smooth beveled edge about 1/4" long. This presses up against the smooth tail stock lip to form your valve seal so make it as smooth and even as possible and it will work better.
Now get some plastic washers that slide easily inside the tail stock piece. I had a piece of scrap plastic around so I turned it on my lathe to fit. It works as a centering guide for your valve to keep it closing and opening in a straight line. (This is one reason other converted valves often fail.) The fit needs to be loose but not too sloppy, say 1/16" clearance.
Now make a top cap. I turned a scrap piece of aluminum so that it fit into the tail stock and had about 1/2" of overhang left at the top just like a cupboard knob. The half inch center hole is threaded to fit the rod, but you could just use a clearance hole and a couple of retaining nuts on the top and bottom. You need to be able to adjust the height of this cap as this is the regulator that controls the pump cycle frequency and efficiency. A giant wing nut would work too, just something to hold the valve stem from falling out the bottom due to gravity.
Now assemble your valve. Put about 6 0z. of weight on the bottom of the threaded rod. (I drilled a 1/2" hole in a piece of scrap steel, you could use heavy washers, just smaller diameter than the hockey puck which sits nicely flat against it. Put the puck on the rod then a washer on top about 1/2" smaller than the puck bevel then lock it in place hard with a retaining nut. (This valve cycles 2.5 times per second and receives lots of force (remember that water hammer discussion earlier, well, the hammer part is for real!) so lock it down strongly. This is another reason foot valve conversions fail as there is no way to stop the valve assembly from wobbling all over the valve body and it wears the stem or guide too quickly and frequently pops the foot valve O ring off the groove. That can't happen with my brute of a valve.)
Now put another retaining nut on the rod about 2" above the puck assembly. The valve cycles up and down about 1/2" so you want your plastic center guide to sit above the exhaust ports when it's all assembled and resting in the down position. Now put a retaining nut on top of the plastic center guide and tighten it down.
Almost there. Slide the valve stem assembly into the reducer so the threaded rod sticks out the top. Now spin on your top cap adjuster until it slides into the top of the tail stock and permits the valve assembly to move up and down about 1/2". Put a wing nut on top of the cap to hold it in place. You will have to loosen or tighten this cap a few turns at a time to make your pump operate optimally.
You need the picture of all the valve parts to see that it's easier to build than than it sounds below...so let's GO...
I had a 2" to 1.5" copper reducer with a short piece of 1.5" pipe attached and that makes the valve body. I also had a 6" brass tail stock sink connector that I inverted and soldered inside the reducer because that had a nice smooth lip that makes a perfect valve seal with no work at all. If you have a new reducer and smooth it off with sand paper, you likely don't need the tail stock step. Now drill a 3/4" hole all the way through the pipe just above the reducer and smooth the edges and presto, your exhaust port is all done.
Next problem... how to replace the O ring seal used in converted foot valves. It routinely wears out or slips out of place and stops your pump. So, let's not fool around. Take a hockey puck and use a hole saw to make it 1.85 " in diameter so it fits inside the 2" reducer and has lots of clearance around the outside. Drill a 1/2" inch hole exactly in the center and put a bolt and nut on it so you can hold it in your drill press. Then spin it with a file against the edge so you get a nice smooth beveled edge about 1/4" long. This presses up against the smooth tail stock lip to form your valve seal so make it as smooth and even as possible and it will work better.
Now get some plastic washers that slide easily inside the tail stock piece. I had a piece of scrap plastic around so I turned it on my lathe to fit. It works as a centering guide for your valve to keep it closing and opening in a straight line. (This is one reason other converted valves often fail.) The fit needs to be loose but not too sloppy, say 1/16" clearance.
Now make a top cap. I turned a scrap piece of aluminum so that it fit into the tail stock and had about 1/2" of overhang left at the top just like a cupboard knob. The half inch center hole is threaded to fit the rod, but you could just use a clearance hole and a couple of retaining nuts on the top and bottom. You need to be able to adjust the height of this cap as this is the regulator that controls the pump cycle frequency and efficiency. A giant wing nut would work too, just something to hold the valve stem from falling out the bottom due to gravity.
Now assemble your valve. Put about 6 0z. of weight on the bottom of the threaded rod. (I drilled a 1/2" hole in a piece of scrap steel, you could use heavy washers, just smaller diameter than the hockey puck which sits nicely flat against it. Put the puck on the rod then a washer on top about 1/2" smaller than the puck bevel then lock it in place hard with a retaining nut. (This valve cycles 2.5 times per second and receives lots of force (remember that water hammer discussion earlier, well, the hammer part is for real!) so lock it down strongly. This is another reason foot valve conversions fail as there is no way to stop the valve assembly from wobbling all over the valve body and it wears the stem or guide too quickly and frequently pops the foot valve O ring off the groove. That can't happen with my brute of a valve.)
Now put another retaining nut on the rod about 2" above the puck assembly. The valve cycles up and down about 1/2" so you want your plastic center guide to sit above the exhaust ports when it's all assembled and resting in the down position. Now put a retaining nut on top of the plastic center guide and tighten it down.
Almost there. Slide the valve stem assembly into the reducer so the threaded rod sticks out the top. Now spin on your top cap adjuster until it slides into the top of the tail stock and permits the valve assembly to move up and down about 1/2". Put a wing nut on top of the cap to hold it in place. You will have to loosen or tighten this cap a few turns at a time to make your pump operate optimally.
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Mar 1, 2009. 11:41 AMhorape
says:
In the diagram there is a 2" to 1.5" reduction T, but that connects to a 2" to 1.5" reducer on the gate valve. Should it be a 2" T without reduction?
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3
Mar 2, 2009. 6:36 AMeltigre (author)
says:
I was attempting to save you the cost of the reducer. You can either use a full 2" T plus a reducer on the output side to get you down to 1.5" so you can connect to your check valve or you can eliminate the reducer by getting a reducing T that outputs to 1.5" Basically, you just have to connect the plumbing together. My pump is a bit less elegant because I used some odd size stuff I had on hand and then bought various reduces and connectors to make it all fit. Sharp eyes you have there...
Reply
Mar 3, 2009. 4:40 AMhorape
says:
Excuse me if I'm being dense, but if you put a reducer T, where does the hockey puck gets into? Doesn't it must be on the 2" section so it goes up and closes the valve against the reducer? Thanks.
Reply
3
Mar 3, 2009. 6:28 AMeltigre (author)
says:
Hey Horape, Here is a diagram that may help explain it. The pump I built shows a lot of unnecessary connectors because I used recycled and salvaged plumbing parts I had on hand, If you build one, you can make the connections with fewer parts than you see on mine.
Reply
Mar 3, 2009. 6:23 PMCrispinPemberton-Pigott
says:
Dear Horape and El Tigre RE the drawing from El Tigre If you reverse the position of the two valves so the delivery valve is where the waste valve is now on the Tee, you will pick up at least 3% in system efficiency for free. This is because the amount of dead water between the flow and the delivery valve, which has to be restarted on each stroke, is less in volume. If you can use a shorter valve, the mass is again reduced. The snifter valve needs to be at least 1 to 1-1/2 inches above the top surface of the waste valve so be careful on that score. The air chamber on that design should be completely full of air, no water at all. If you have a 2 inch drive pipe, the pump body should be one pipe size larger (2-1/2 inch). The waste and deliver valves should also be bigger so the hole through them is about the same size as the drive pipe. If you place a bolt on an angle into the delivery valve to limit the travel, it will last longer and pump more water. The correct setting will be found experimentally, about 1/2 open is a good start. In summation, use a 2-1/2 inch delivery valve blocked so it can only open 1/2 way. Filing the very sharp edge off the opening will increase the water volume a bit but only take off a small amount as it is also the seating surface. Regards Crispin
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3
Mar 4, 2009. 5:25 AMeltigre (author)
says:
Thanks again Crispin, That is some good info you don't seem to find anywhere else.
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