WIKA In-line Diaphragm Seal (981.27)

For flange connection, flange-type


  • For direct, permanent installation in pipelines
  • For flowing, pure and aggressive media
  • Chemical process industry
  • Petrochemical industry

Special Features

  • Completely round, no corners and edges
  • For direct installation between two flanges
  • Wide choice of special materials

Sales Contact (Wika.sales@asyatrafo.com)




Process connection
Sealing face, Form B1 or ASME RF 125 … 250 AA For flanges following ASME B 16.5, 1″, 2″, 3″, 4″
Nominal size: see drawing and tables on datasheet

Pressure rating
Class 150/300

Pressure ranges
preferably mounted to pressure gauges NS 63, 100, 160 or pressure transmitters, Pressure ranges 0 … 15 to 0 … 600 psi

Housing and material of wetted parts
Stainless steel (AISI 316L)

Measuring instrument connection
Pressure gauge or transmitter directly welded, process pressure transmitter with threaded adapter


Process connection

  • Larger nominal sizes
  • Other flange connections on request
  • Sealing faces per EN 1092-1, form B2 or per ASME B 16.5, RF 125 AA, 500 AA, RFSF; EN 1092-1 groove and tongue; projection and recess; ASME B 16.5 snap ring groove form RJF (limited for special materials, please request)
  • Flame arrester approved for zone 0

Material of wetted parts

  • Stainless steel 316TI, 316, 321, Monel, Hastelloy B3, C22, C276, tantalum

Measuring instrument connection

  • Capillary, when ordering please specify: length of capillary
  • Cooling tower (for directly mounted gauge when fluid temperature > +284 °F)


  • Custom lengths between 3 and 25 ft.
  • White PVC – Armor protection