Hello, I have an old compressor that I use. It doesn't have enough airflow or pressure to move the water out of the lines by itself. The way I get the pressure and volume to make sure the lines are clear at closing is, after backwashing and cleaning the filter and pump, I put them back together. Then close the valves leading back to the pool and let the pressure build up in the filter itself - have to be careful here and watch the pressure. When the pressure is high enough, I use a little over the normal operating pressure, I set the valves so the line I am going to plug is the only outlet from the filter/pump. I open the valve and get both the needed pressure and volume. It might take a few times of doing this but eventually there will be only a fine mist from the skimmer lines and heater drain lines. For the bottom drain and return lines, since they are still under water, I follow the same procedure but have a plug ready to install while the air is still coming from the lines. For the bottom drain I just use the valve(s) to close off that line while air is coming from the drain.
The control valves that I have will allow me to move the control lever all the way around to block the flow from the filter/pump. I have to loosen the set screw so I can lift the lever over the stop tab. Check the operation of the valves before doing this - DO NOT FORCE the valves.