This page is new and obviously under construction. Readers are warned that the plans linked by this page and the information on this page are preliminary and subject to change without notice. So, until we've got a better handle on what we're doing, feel free to visit and look around. We'll remove this notice when the information here has firmed up to the point that it's considered dependable.
This is a cut away photo of one of the check valves. For now they are made from two 1 1/4" solvent to 3/4" FPT reducers, a 1 1/4" solvent union and and a 7/8" Delrin ball with a hand made spacer and what I'll call a spider, also hand made. More information on how these were made can be had here.
Pump cylinders are made by gluing a cap onto a nine inch long piece of four inch diameter PVC pipe.
Here one of the cylinders is drilled with a 7/8 inch hole saw. An ordinary twist drill or a spade type drill will work also. I just happened to have a hole saw that was the right size. The back of the cylinder is supported and steadied by a jig made from a coupler with a piece of wood attached. The jig keeps the pump cylinder from rolling while it's being drilled.
Here the back side of the jig is shown. The wood has been cut at an angle that allows the pump cylinder to be rotated 36 degrees for a second hole to be drilled. This jig is not absolutely necessary, but it does make drilling holes in the the pump cylinders at the proper angle much easier, particularly if more than one pump is to be constructed.
The holes are threaded using a 3/4" pipe tap. If you have a tap handle use it. Otherwise an adjustable wrench will do. Don't over drive the tap, and take care to start it as near perpendicular as possible.
Pump pistons and seal retainers are made from sections of PVC pipe that have been heated and flattened. This shows three sections of pipe that have been cut, heated and partially and then completely flattened for purposes of illustration. More information on this procedure is available on the pistons and seals page.
Here the check valves have had pipe nipples and hose barbs installed. Note that the valves are plumbed so that two will direct water into the cylinders, and two will direct water out of the cylinders. Thread tape assures a tight water and more importantly air tight fit. Air leaks on the vacuum side of the pump will prevent proper operation.
Pump Assembly Page