So here goes for the operation of the pump.



As the pump cycle begins, water flows down the stand pipe, and up through the swing check valve. Water begins to flow faster and faster around the flapper in the check valve, until friction draws the flapper up, slamming it closed. This causes a pressure spike in the pump body, as the water flowing down the stand pipe at some speed no longer has anywhere to go. This pressure is relieved by some of the water flowing across the spring check valve, over onto the pressure chamber side of the pump. Once past the swing check valve, it cannot return, and has to stay there. When the pressure difference across the spring check valve drops, the valve will close and water will stop flowing through it. The lower pressure will allow the swing check valve to open again, beginning the cycle all over again.



Troubleshooting



So what if this doesn't happen? Well, first things first, check and make sure that it's "on". That is to say, make sure both the 1-1/4" and 3/4" valves are in fact open.



Sometimes water will flow out of the swing check valve, then the valve will slam closed, but nothing will happen. If this occurs, tap on the flapper in the check valve to open it up again, and let the cycle begin again. In theory these pumps need some back pressure (coming from the pressure tank side) to operate, but I've never had any trouble getting mine going with just some basic tapping and fiddling.



Tuning



Now that it's working, can you make it work better? You'll find that there's a maximum height that the pump can deliver water to. Be patient when trying to find this, as it takes a little while for the pump to achieve the pressure required to raise the water up higher and higher. There are formulas that will tell you how high you can theoretically pump water based on the source water head. Feel free to look them up.



Tuning ram pumps mostly involves varying the water velocity that results in the swing check valve closing. A higher water velocity will generate a larger pressure spike, allowing you to pump to greater heights. But it will also cause a slower cycle, so you pump more slowly. If the valve closes at a lower water velocity, it will take less time for the water to reach that velocity, so the pump will cycle faster, and the water pumped faster, but you will not be able to pump as high. So that's the trade off. Keep in mind though, that this will work without interference 24 hours a day, so combining it with a holding tank, you can get a decent supply of water built up.



To tune this specific design, you take advantage of how gravity acts on the flapper. When the check valve is pointing straight up in the air, the full force of gravity holds the flapper down, so the water must flow past the flapper faster to generate enough drag to raise the full weight of the flapper. By rotating the pump about the main line, you put the flapper's degree of freedom at an angle to the force of gravity, so that less drag is required to move the flapper. You could work out all of this fairly easily with a bit of trig, but I feel it would serve you little use out in the field. Just play around with it, you should find a position that works well for your application.



No Power?

Well, no. This pump derives its power from the potential energy of the water uphill, and by wasting (not in a bad sense) the majority of the water that flows through the stand pipe. It only pumps a small fraction of the water that actually travels down that pipe. But that's fine if you have a stream already flowing down a hillside. Before, you weren't doing anything with all that potential / kinetic energy. Now you are. Hooray for you!

