8000T Series Three Way Body

The three-way Mark 8000T can be specified for use on mixing or diverting services. As a mixing valve, it is designed with two inlets to blend two separate flow streams into a common outlet creating a third fluid. For diverting service, valve features one inlet and two outlets, allowing you to divert the flow from one outlet to the other as required to bypass heat exchangers, coolers, filters or other pieces of process equipment.

The Mark 8000T is a heavy-duty pneumatic control valve developed for standard or low flow industrial process applications. It is recommended for use when service or environmental conditions may be too harsh for traditional three-way control valves.


  • 1/2″, 3/4″, 1”

End Connections

  • Threaded – NPT, BSPT
  • Raised-face flanges (300#, 600#, 900#)
  • Ring-type joint flanges (150#, 300#, 600#)
  • Socket weld (schedule 40, 80 or 160)

Diaphragm Material

  • Buna-N/Nylon

Spring Ranges

  • 3-15 (0,2-0,1); 3-9 (0,2-0,6); 9-15 (0,6-1,0); 6-30 (0,4-2,1); psi (bar). Note: valves using 55M or 85M are not available with  9-15 psi (0,6-1,0 bar) range


  • Standard – ANSI Class lll (Cv’s < 3.5/Kv’s < 3,01), ANSI Class IV (Cv’s 3.5 and higher/Kv’s 3,01 and higher)
  • Optional – ANSI Class VI with soft RPTFE seat (consult factory for other soft seat materials options)