Method 1: Install a Soldered T-Fitting with Two Single Valves

What happens here

This method involves creating a custom assembly. Take a copper T-fitting and solder two short pieces of copper pipe to its horizontal ends. Then, attach two new single shut-off angle valves to these copper extensions using compression fittings, each with its own compression nut and ferrule. This assembly then connects to your existing copper stub-out (hot or cold line). This method provides two completely independent shut-off points, allowing individual control for each connected appliance. While more time-consuming and requiring soldering expertise, it offers a highly reliable and customizable solution.

Goal: For a robust, custom solution, install a soldered copper T-fitting with two independent single shut-off valves, requiring soldering skills.