AMOT internally sensed temperature control valves are completely self-actuating and require no external power source. They are suited for use within the railway industry on large single engine locomotives and also multiple engine DMU’s (Diesel Multiple Units) in applications such as lubricating oil, jacket water (high temperature) circuits, and charge air (low temperature) circuits. Automatic self-sensing control is achieved by the expansion of a wax/copper mixture with positive proportional valve action. A robust construction is combined with very low friction characteristics plus vibration and shock resistance to ensure a long and reliable service life. Seats and sleeves are replaceable. Temperature setting is tamper-proof and the easily installed valves operate in any mounting position, with a leak-tight design that eliminates external moving parts and external dynamic seals. Three-way valve action ensures constant volume flow in the system and gives no restriction during the warm-up cycle to ensure maximum performance. These valves are said to exhibit good over-temperature and over-pressure characteristics.