How much room is available inside a standard home 4” well tube, given the existing well-pump?
The information I found list 4, 5 or 6 inch pipe is generally used.
Sorry that’s not what you asked. I’ll have to do more research to answer your question.
Most home submersible pumps use 1” (nominal) black poly roll pipe to deliver water to the surface. This pipe has an OD (Outside Diameter) of about 1.25”, leaving room for a 2” (nominal) PVC pipe with an OD of about 2.25” (2.5” at the couplings). The actual submersible pump is usually placed well below the standing water level, leaving plenty of depth for a hand pump.
I teach villagers in the developing world to make PVC hand pumps that work great in 40 foot (to the surface of the standing water) or deeper wells. With an added counterweight or a simple conversion to foot power, these work in deeper wells also.
I have not yet posted a “how to make” manual, but this one by EMAS in Bolivia is very similar and they have great videos!
My first student had bored more than 260 wells using a hand auger & installed pumps on them by 1996. Here’s a brief video made back when we were still using galvanized steel pipe for the pump.
http://video.google.com/videoplay?docid=4629383911705480631
A husband & wife student couple in the USA started this organization: