No, doing so could cause an air leak at each pipe joint, packing gland and valve seal. Remember that the water is inside the bag. Unlike the old, plain-steel type tanks, the CA tank doesn't need to be drained.

Isolate the tank from the system and break the connection to it so that any fluid inside can be allowed to escape. The true air charge can't be determined until all the fluid is removed. The air charge will equal the system pressure until the fluid is removed from the bag. If the air charge is higher than the system pressure, there should be no water in the bag and the pressure reading should be the true air pressure reading.
    Remember, the water is inside the bag and the air is between the inside of the steel shell and the outside of the bag. If the tank does not have an air charge, air should be introduced which will squeeze any remaining water out of the bag. When the fluid stops coming out of the system connection, you will read the true air charge.

The air charge pressure should be equal to either the system fill pressure or the PRV setting if the tank is at the same elevation as the PRV. If the tank is located at any other elevation in the system, the charge pressure in the tank should be the cold pressure of the system at that elevation.

A chilled water system is filled with water at a temperature between 50 and 60ºF. When the chiller is turned on, the temperature of the water drops to 45ºF. When the water contracts, the system pressure drops, and the fill valve allows more water to enter the system to maintain the system pressure.
    If the chiller shuts down and the water in the system warms up to room temperature, the rise in temperature from 45º to ambient will cause the water in the system to expand. Without an expansion tank, the relief-valve would blow. The tank can be smaller than the one used in a hot water system, because the temperature is rising from 45ºF to ambient, instead of from ambient to 200ºF.

The screen is there to protect the bag from being forced out of the connection port when installed in a high pressure system.

The required pressure is dictated by the cold fill system pressure. The only water that should enter the tank is the thermally expanded water of the system. The tank precharge pressure should equal the system pressure, giving you equilibrium in your system.

When using this control, you can expect a 12-15% energy savings but this may vary more or less due to variables in the whole system.