The requirements on heating, ventilation and air conditioning systems (HVAC) for use in road passenger transport vehicles are diverse and exacting, with the requirement to provide a comfortable passenger environment. Valve durability and longetivity is a significant issue, with valves expected to last at least as long as other system components, such as motors, meaning they are often installed in hard-to-access areas. Designers of modern vehicles must also consider the need to minimize electrical magnetic emissions, which can affect the reception of both mobile phones and radios. Meanwhile, the precise positioning needed to accurately control temperatures cannot be achieved if the valve is subject to high levels of hysteresis. The electrical connectors used in a valve can also impact performance. Ceramic products enable the creation of a very broad variety of flow characteristics and capacities to meet individual customer requirements.