Hi everyone
When I was at the AMW for the 2025 fair, I went over to the windmill cluster on the south end, and noticed that all of the cylinders under the windmills were above-ground. Obviously they're usually underground at the water level, so I assumed this was done for easier maintenance.
Anyway my questions are: Is an above ground or below ground cylinder recommended, and what are the upsides and downsides of an above ground cylinder?
I'm thinking they may have been more for demo purposes. If a cylinder doesn't have water in it, it won't start pumping is what I've found. My demo pump jacks hooked to gas engines with cylinders I always have to prime them ( fill them with water) before they will start moving water. That's what I've learned, someone else may know better! I'm just a rookie not a real windmill man.
Ok, heres the scoop. If a person drives a well point, (sand point) for a shallowwell, then the cylinder choices are a couple. One, you dig a pit and put the cylinder in the pit, and it wont likely freeze in the winter, if you put a weep hole above the cylinder in the pit. Two, put the cylinder a couple ft below grade, hopefully to keep it from freezing. In this case, a weep hole is only practical if you put a bucket down along the water pipe, and vent the weep into the bucket. this has an inherant problem, having to dig to the cylinder to service it when its time. I have a customer digging to his cylinder at this very moment. To get the cylinder off the well pipe, you need to dig deep enough and wide enough to accomodate the cylinder, and the pipe wrenches it takes to get it unscrewed without knocking a bunch of dirt down the pipe, and swing at least a 24 inch pipe wrench. Three is like the above, but put a petcock or valve on the weep, to open in the winter. Four, is to put the cylinder above ground, in areas that dont freeze much, or are unlikely to freeze. Above grade cylinders are without weep holes, obviously. If you put a weep below the cylinder, it wont drain the cylinder due to the bottom check, so...for warm climates, temporary installations, or a high water table, at least a person can get water without a drilled and cased well. I have done every method i have mentioned, more than once.
Call Dan Benjamin for parts. P M me for the phone number. IF YOU TALK TO HIM, AND HE HELPS YOU, THEN BUY FROM HIM. IT CREATES GOOD KARMA.
Windy Bob has an excellent explanation of the issues involved regarding freezing weather.
Another relevant issue is: how deep is the water in your well? My understanding is that what is actually happening in the above ground cylinder is the moving plunger is creating a low pressure area inside the cylinder, and water is being pushed up into that low pressure zone by atmospheric pressure. At sea level, standard atmospheric pressure is approximately 14.7 pounds per square inch, which, I am told, means a cylinder can suck water up a pipe a maximum of about 28 feet.
If the water in your well is farther down than that, an above ground cylinder is not going to raise it. Then you are better off to have a drilled, cased well and extend a drop pipe down in the well to submerge the cylinder. Inside the drop pipe are sucker rods to connect the cylinder to the windmiil. The main limit on how high you can raise water from a submerged cylinder is whether the windmill develops enough torque to lift the weight of the water column (plus sucker rod). Aermotor has a table you can use to determine how to size the cylinder and windmill diameter optimally to raise water from a given depth.
