Pilot valves are often used in larger refrigeration plants with many consumers. A pilot valve is an add-on to the in-line valve. It enables a small force to operate the larger valve like in a hydraulic piston.
A pressure transducer is fitted in a heating-, cooling-, or ventilation system. It measures the pressure in a specific location in a system and converts it into a signal which can be read by an instrument.
PROFIBUS is a network technology mostly used in process industries but you can find it also in building automation. It is a standardised technology for data communication, managed by Profi International.
PUR foam is used for insulation of almost all cooling pipes and cooling installations due to its impermeablity and is therefore used extensively in the production of insulation jackets for pipes, fittings, etc.