I recently replaced a bad pressure tank. The tank in question is water logged (water is on top of the bladder, not under it). The tank is full of water and as such weighs a ton. It is completely disconnected and will not drain. The air valve is also damaged and is stuck in the closed position. I cannot remove it. What is the risk in drilling out the air valve to drain the water out of the tank? My system run a 40/60 pressure setup. Any other methods to drain this tank so i can get it out of my basement?