Mark 978JD Series – Control Valve

The Mark 978JD (Jorlon diaphragm) meets ASME BPE 2009 guidelines and is ideally suited for a wide range of flowing media in both the clean utility and process areas of sanitary and aseptic systems. High rangeability, true characterized trim, high capacities, superior temperature and pressure ratings, facilitated by a superior diaphragm, make the MK978 the sanitary control valve for sterile process, buffer, WFI and acid metering and clean gas and steam services. Whether the need is to control pressure, temperature, flow, pH or another variable, the MK978 is the right valve for your process.


  • Lifetime warranty on Jorlon diaphragm
  • All stem guiding above the diaphragm (wet process) to eliminate particulate generation
  • Self-draining geometry in most vertical or horizontal orientation allows installation flexibility
  • INLINE horizontal connections are offered as an option on most of our models
  • Corrosion resistant actuator coating with SST fasteners
  • Extended PEEK guide bushing ensures smooth, stable movement throughout entire stroke length regardless of valve orientation (on it’s side or upright)
  • Contoured plug design for true equal percentage or linear flow characteristics throughout entire stroke length
  • Bolted bonnet provides enhanced strength and durability over clamped bonnet designs especially when units are mounted horizontally
  • Corrosion resistant SST Namur yoke assembly suitable for washdown, permitting easy mounting of positioners
  • Solid ASME A479 316L barstock construction offers excellent chemical resistance, ensures consistent material integrity and surface finish FDA/USP Class VI Jorlon diaphragm resistant to aggressive chemicals, suitable for indefinite steam service, offers unsurpassed service life