Mark 978 series of valves are suitable for use in steam, fluid or gas applications. All wetted parts are 316L stainless steel and finished to 0.5 microns Ra and electropolished. The availability of a diphragm seal version makes the valve suitable for Aseptic applications. Valves can be used with a direct air signal, or when fitted with a positioner, 1 4-20mA or pneumatic control signal.