Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations are intended to control the water temperature to wall mounted shower heads either in individual showers or in tub/shower combination fixtures in order to reduce the risk of scalding and thermal shock. These devices are intended to be installed at the point of use, where the bather or bather's attendant has access to flow and final temperature control mechanisms, and where no further mixing occurs downstream of the device. The three types of individual control valves covered by this standard are:

1. Pressure balancing valves (Type P) have a mechanism that senses incoming hot and cold water pressures and compensates for fluctuations in either to stabilize outlet temperature.

2. Thermostatic valves (Type T) have a mechanism that senses outlet temperature and compensates for fluctuations in either incoming hot and cold water temperature and/or pressure to stabilize outlet temperature.

3. Combination thermostatic/pressure balancing valves (Type T/P) sense outlet temperature and incoming hot and cold water pressures and compensates for fluctuations in incoming hot and cold water temperatures and/or pressures to stabilize the outlet temperature. These devices are intended to be the final temperature control.