How does a hydraulic ram water pump work?

Try this link there is a simple picture and an explanation.

http://www.lifewater.ca/ndexram.htm

The water must have some elevation drop... the RAM is made of several valves (check & clack) and a pressure tank. The water flows down into the pump through a pipe, and the flow closes the clack valve... the water then builds pressure, which forces some water up through the check valve (output). When the water pressure reduces to a certain point, the check valve closes, the clack valve opens, and it all starts over again! For a RAM to work, you have a certain percentage of water loss. We've used this type of pump for irrigation purposes, and it does work pretty nicely.

Water is allowed to build up some speed in a pipe. Then a valve suddenly stops the flow. Since the water in the pipe had some momentum, it doesn't want to stop so quickly and you get a spike in the pressure. The high pressure that develops allows some water to go through another valve and push upward to a higher water tank.

Note that only a small percentage of the water gets pushed up to the high pressure (high elevation) tank. So you have to have ample water. Also the water has to have a little motion to it. You can't build one of these pumps near a stagnant pond or slow moving river.

In the oil business we called it the hammer effect.

we have tanks about 700 ft. above the ocean. we had a small leak so they turned the valve off at the tank.there was another valve on the beach which they closed. This is a 36 in. line . all the repairs complete they opened the valve at the tank,not knowing that the oil had pulled a vacuum on the line before they closed the second valve . so when they opened the tank valve the oil rushed down and with the vacuum it accelerated and blew up the second valve.

It creates a pressure difference forcing the ram one way or another by attempting to compress something that is uncompressable, such as a liquid.