Model 990.31

Threaded Process Connection, Diaphragm Seals

Plastic Design

Selected documents
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  • Process instrumentation in chemical plants
  • Plating industry
  • Waste water treatment
  • Fertiliser industry

Special Features

  • All-plastic design
  • Metal-free
  • Process connection with thread for direct mounting, but also suitable for bonding (PVC-U) or welding (PP, PVDF)


Pressure rating
PN 10 (with water, 20 °C)

Suitable pressure ranges
0 ... 1 bar to 0 ... 10 bar
not suitable for + / - ranges and vacuum ranges

Operating pressure and process temperature
See also diagram pressure-temperature rating on data sheet

    Upper housing (instrument connection)
  • G ¼ female
  • G ½ female
  • Material:
    PP (polypropylene), fibre-glass reinforced, blue RAL 5022

Diaphragm with sealing ring
EPDM, with PTFE foil on the medium side

    Lower housing (process connection)
  • d 25, G ¼ female (optional ¼ NPT)
  • d 32, G ½ female (optional ½ NPT)
  • Material:
  • PVC-U (polyvinyl chloride), grey RAL 7011
  • PP (polypropylene), grey-beige RAL 7032
  • PVDF (polyvinylidene fluoride), opaque, yellowish white
  • Multi-purpose connection, optionally via threaded neck, bonding neck (PVC-U) or welding neck (PP, PVDF)

Mounting position
any position possible, preferably measuring instrument on top

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