Two-Way - Graphite Disks


The TWO-WAY Type Graphite Disk is dual rated to protect against two different pressures in opposite directions.


  • Dual rated to protect against two different pressures in opposite directions
  • Applications include protection of storage tanks against both excess vacuum and overpressure when single vessel entry is required
  • Sizes 1-1/2” (38 mm) thru 24” (610 mm) diameters
  • Designed to fit industry standard flanges ASME B16.5, ISO and JIS
  • Burst ratings 0.25 psig (0.02 barg) to 1000 psig (68.95 barg) or higher
  • 0% manufacturing range
  • Operating pressures to 90% of the disk’s marked burst pressure. Contact ZOOK for operating ratio for burst pressures below 40 psig (2.76 barg)
  • Temperature ratings –290°F to +430°F (–179°C to +221°C). Contact ZOOK for higher temperature ratings. The specified temperature shall be at the disk location at the time when the disk is expected to rupture
  • Carbon steel armor standard, 316SS optional
  • Furnished complete with PTFE gaskets attached. Other gasket materials are available
  • Generally a minimum differential of 10 psi is required between burst ratings. Contact ZOOK for other burst rating combinations
  • PED (CE) compliance available


Two-Way Specifications