311-312 Midi-Diaphragm Seals

The Ashcroft® 311 and 312 midi-diaphragm seals or isolation devices are used in confined areas to protect measuring instruments. Used to ensure process compatibility, they are also applied when process media exhibits high temperature and pulsation. This model is ideal with limited space installations.

Key Features:
  • Compact and lightweight design
  • Choice diaphragm and lower housing materials
  • All-welded construction
  • Volumetric displacement allows attachment to:
    63 mm and 3 1/2″ gauges (0 … 4 bar to 0 … 60 bar)
    100 mm and 4 1/2″ gauges (0 … 7 bar to 0 … 60 bar)
    Transducers and switches
  • Rated up to 70 bar
Specifications:
  • Style:
    Type 311: threaded
    Type 312: threaded with flushing port
  • Process size:
    Type 311: 1/4″ to 1/2″ NPT male; 1/4″ to 1″ NPT female, 1/2″ to 1 1/2″ R/BSPT/JIS male
    Type 312: 1/4″ and 1/2″ NPT female

The 311 and 312 midi-diaphragm seals are ideal where process protection is essential:

Process Market:
  • Oil and Gas
  • Refineries
  • Chemical and Petrochemical
  • Water and Wastewater
Process Applications:
  • Oil and Gas Fracking
  • NACE Compliant Processes (Sour Gas Separation)
  • Biogas and Biodiesel
  • CRN
  • GOST
  • NACE
 

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Tools

  • Distributor Locator

    Locate an authorized Ashcroft distributor in your area.
  • Materials Selector

    Use the selector to review compatible wetted materials and requirements of your application.
  • Unit Convertor

    Need to convert measurement units? Check out our quick and easy approach to pressure, temperature and flow unit conversions.

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