This is my first post. I've been reading this forum for several years and am thoroughly impressed with the knowledge available on here. My house was built in 1987. I've owned it for five years now. The water heater was replaced in 2011. I have never paid any attention to my water heater until last weekend when I replaced the line to the icemaker as part of a kitchen renovation. The outlet is directly connected to polybutylene as you can see in the picture. The inlet is PEX with a tee that connects to polybutylene that connects to copper that goes in the wall. The relief valve is connected to polybutylene and connects to copper that goes into the wall. There is a copper line that comes from the wall with a valve that is near the tank drain. The valve was closed. I opened it and no water came out. I think this is connected to the relief valve. I want to replace the polybutylene. On the outlet side I can sweat a threaded fitting onto the existing copper pipe and connect a corrugated copper hose. The inlet and relief connect that branches off to the wall are in tight quarters behind the water heater. I think I can heat up the existing copper elbows and remove them. Then sweat on a new elbow with copper stub ups that gives me room to work. Any thoughts? What corrugated copper lines do you recommend?