Lowering Well Casing

My Uncle Would Like To Relocate His 525 Gallon Vert. Galvanized Tank Approx 50' From His Well. Also,wants To Lower The Top Of His Well Casing Below Ground.(the Well Casing Is Approx. 1' Above Ground And 2' From The Tank Now) Please Advise Me On Proper Check Valve,schrader Valve, And Pressure Switch Locations.thanks In Advance..................

He should not reduce the height of the casing. Do so can cause surface water etc. to get into the well.

To move the tank, replumb the new one as the old one is now, don't add check valves etc. etc.. The pressure switch should be on the tank tee.

Leave your check valve and schrader valve at the well, or you will get too much air in the tank. Pressure switch should go with the tank. Countersinking a well head is illegal in most states, an is not a good idea anyway. Just get one on those fake rocks to put over the well.