These valves are specially developed to regulate pressure and temperature in refrigeration, freezing and air conditioning plants with fluorinated refrigerants and ammonia. This is a pilot operated main valve with screwed-in pilot valves mounted in an external pilot line. Main valves are used in refrigeration plant with dry evaporation , pump circulation, natural circulation. The regulator is available in two variants, first is designed to accept one pilot valve either screwed-in or mounted in an external pilot line. Second will accept three screwed-in pilot valves mounted in an external pilot line. Thus several functions can be performed by the same line.