302-303 Flanged Diaphragm Seals

The Ashcroft® type 302 and 303 flanged diaphragm seals or isolation devices protect pressure measuring instruments. Used when process compatibility is required, these are also applied when media exhibits high temperature or the potential to clog an instrument connection. Ideal for satisfying many challenging applications.

Key Features:

  • Wide selection of diaphragm and lower housing materials
  • Diaphragm (elastomer) clamped between top and bottom housings
  • Flush port (type 303) provides easy cleaning / flushing due to process media prone to clogging


  • Style: Type 302: flanged Type 303: flanged with flushing port
  • Process size: 1/2" to 3"
  • Flange rating: 150, 300, 600, 900 & 1,500 class

The type 302/303 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
  • Biogas and Biodiesel