Cooling water systems operate in low or high temperature ranges, for example cooling water cycles for cooling the main engine, auxiliary diesel engines or auxiliary systems such as the charge air compressor, air conditioning and provisions cooler or cycles for utilising waste heat to produce drinking water as well as to heat the tanks, service water and living areas.

Ships need ballast water to improve their stability and balance their load; this water is carried in tanks, the double bottom, the fore and aft peak tanks and side spaces.

Exhaust gas and auxiliary boilers are used to generate thermal oil or steam – for example, for heating or cleaning tanks, preheating HFO, producing drinking water or heating water and living areas. Today, steam turbo-generators are also used to generate electricity for very large engines.

HVAC systems serve to condition the air in living areas and provisions rooms. Amongst other things, HVAC systems consist of a closed water cycle in which a volume flow of water conveys heat or cold from the generator (heat exchanger, boiler, chiller) to the consumer (cooler, heater) with the aid of circulating pumps. ARI STEVI control valves maintain the correct balance in this cycle by controlling the volume flow.