---INTRODUCTION--- Q: What's pressure balance cartridge? A: A pressure balance valve is a sophisticated plumbing device that reacts to changes in the pressure of the delivery water. Typically, both hot and cold water sources are fed into the valve, and its job is to ensure that the volume of water that leaves it is a constant mix of these two sources, even if the delivery pressure of the two sources changes. This is very important to keep the temperature of a shower constant even when the supply is not. ---ABOUT CHIXIN CARTRIDGE---