This project come from this article I found online:
Copper to build the accumulator tanksThese will accomplish a number of useful functions. Essentially they are air filled tanks, and as water is pumped into them the pressure will build. They will help create a more smooth flow of water through the system, they will allow hot water from the on-demand heaters to accumulate so I get to use all of it and it will get good and hot, and they will decrease the cycle time for the pumps, (which are DC powered /which means they will generate power loss through the wiring to them) and there by use less power over-all.
Two things about these valves that bears mention is that they are made of steel, which reacts strongly with copper, so it will be important to get the rubber seals firmly in the holes drilled in the caps, and two, they have lead in them. Of course no one wants lead in their water. They will be sitting at the top of the tank, and a pocket of air will get compresses at the top as the tank fills with water, keeping the lead in the valves from coming in contact with the water.Mr. Rusk agreed to teach me how to sweat copper pipe together, so we set everything up and got started.
First step: pre-drilling the hole for the valves.It was easiest to put the pipe in the vice for sanding. Sand the two surfaces of the copper you want to join and then add a thin layer of flux to each clean and shiny surface. The heat the metal and when the temp is right to let the solder flow, feed it into the joint.
First joint to make was the cap to the pipe, then I installed the valves.
Thanks for your help Mr. Rusk!