Starting at $277.27
  • Usually ships in 3-4 weeks



  • All-welded metal construction
  • No gaskets or bolts
  • 2.5 & 3.5in gauges from 15 to 1000 psi
  • 4.5in gauges from 30 to 1000 psi
  • Top housing material 316L stainless steel standard
  • Diaphragm materials:
    • 316L stainless steel
    • Hastelloy C
    • Tantalum
  • 1/4 NPT or 1/2 NPT instrument connections

This product is an accessory for the following products:


The Ashcroft Type 311 / 312 diaphragm seal is compact in size to fit into space restricted areas. It is designed to protect transducers, mini-switches, and pressure gauges with 3.5 inch or smaller dial sizes from corrosion, plugging or freeze-up. The all-welded metal construction prevents process media leakage. It is rated for 2500 psi at 100°F and has a 316L stainless steel top housing standard. Lower housing materials include 316L stainless steel or Hastelloy C. Diaphragm materials include 316L stainless, Hastelloy C, or Tantalum. 1/4, 1/2, 3/4 or 1 NPT process connection sizes are available and the instrument connection is 1/4 or 1/2 NPT.