What are the exact diffferences between a single and a double pipe jet system? I see the diagrams of the two and should see the answer to my question. I have two pipes leading from the pump to the well head that enter some type of metal casting that's attached to the well head. I take it this is a single pipe system.

In either case, how does a person drain the water out of the well head to prevent freezing during winter. There's a cap on one of the pipes and when removed the cap has water at the top of the pipe.

I know draining down about five feet will keep the well from freezing during winter, but how do I to get the water level down to that point? Hand pump or sipon the water out?