ASSE 1016 covers the delivery of water at the individual fixtures that are adjusted and controlled by the user. Therefore, it addresses very precise and immediate temperature regulation requirements. This standard covers three types of valves: Pressure Balancing, Thermostatic and Combined Pressure Balancing/Thermostatic. Watts ASSE 1016 listed valves meet the thermostatic requirements of this standard.
ASSE 1017, on the other hand, does not address final temperature control at fixtures and appliances. It is concerned with valves used at the source of hot water for distribution to the supply system, and therefore allows wider variation of the outlet temperature at higher flow rates.
ASSE 1017 listed devices should never be used to deliver water directly to the user. These valves should be used in combination with an ASSE 1016 and/or ASSE 1070 listed devices.
ASSE 1070 is a recently approved standard and the newest of the three standards. It covers control of maximum temperature to a fixture or group of fixtures; such as sinks, lavatories or bathtubs. The device may either be the final temperature regulation or have water further tempered downstream with the addition of cold water.