End-of-Line Pressure / Vacuum Conservation Vent – Improved Performance


Protectoseal Series 8540G Improved Performance, Aluminum, End-of-Line Pressure / Vacuum Breather Vent provides quicker pressure pallet lift, and improved flow performance at low overpressures just above the relief set point. This provides the benefit of higher flows at lower overpressures which can be beneficial in storage tank vapor control schemes requiring tight operating bands with the tank’s emergency relief vents, tank blanketing valves and other associated devices in their vapor control system.


  • “Air-cushion” pallet design for low leakage performance of no more than 1 SCFH at 90% of the set pressure
  • Pallet assembly guides and center pallet stem guide to ensure proper alignment of pallet assembly on the seat and smooth lifting and reseating action
  • Unique design allows for quick lift of the pallet and higher flows at lower overpressures
  • Automatic condensate drainage design to mitigate freezing, binding and clogging
  • Swing-bolt design facilitating inspection and easy maintenance
  • Serialized unit and associated weights for easy identification and traceability
  • Sizes: 2” (DN 50) through 12” (DN 300)
  • Flange Connections: Mates with 125# ANSI and DIN PN 16
  • Materials: Aluminum (refer to Series 8540H for other materials)
  • Certifications: Conforms with the latest ATEX Directive
  • Standard Setting Range*: Pressure: 0.5 – 48 oz/in2 | 2.15 – 206.84 mbar
  • Standard Setting Range*: Vacuum: 0.5 – 23 oz/in2 | 2.15 – 99.11 mbar

(Settings vary by size)

  • Flange Connections: Other drilling patterns available upon request
  • Diaphragm Materials: FEP, Viton®, Buna N, EPDM, Neoprene diaphragm materials; other materials available upon request
  • Settings: Non-standard setting available
  • Special Coatings: PROSHIELD™, FEP and Kynar®
  • Instrumentation: Mechanical or electronic lift indicator
  • Material certifications for castings
  • Clamp-on “Steam-Jacketing”
  • Pure-Tech™ Design – Special cleaning and packaging for the storage of ultrapure liquids


Viton® is a Registered Trademark of E. I. DuPont de Nemours & Co., Inc.
Kynar® is a Registered Trademark of Arkema, Inc.