Hello knowledgeable people. I am replacing my 60-gallon electric water heater, and I have this unknown elbow part on the cold water intake piping. It is most likely 15 years old, like my water heater. What it is? Do I cut on the A line and replace it with a new one? Do I cut on the A line and not replace it? Do I cut on the B line and keep it? Thanks for your advice.