OsecoElfab’s PRDI Rupture Disc Holder

The OsecoElfab PRDI Insert Rupture Disc Holder is a reduced diameter, flat-faced flange assembly that bolts between standard ANSI pipe flanges and fits within the bolt circle. The PRDI has a flat seat and uses a raised nubbin sealing surface to create a metal-to-metal “bite” seal between the PRDI inlet, and the rupture disk inlet seat surface.  This holder allows the rupture disc to be preassembled to ensure it is properly seated before installation into the pressure systems. PRDI Insert Holders are available in standard ANSI flange ratings up to 12″ and are offered in three overall height arrangements.

  • The PRDI is for use with the PRO+, PRO+KRGL, PCR, PSR and PLR rupture disks.
  • The PRDI is compatible with the AMS, SVT, and LPSF burst disk indicator sensors.
  • The PRDI is available in line sizes ranging from 1 inch diameter all the way up to 12 inches diameter.
  • The PRDI is compatible with service temperatures ranging from cryogenic temperatures all the way up to 900 degrees F.
  • The PRDI is available in all OE standard materials (316 Stainless Steel, Nickel 200, Inconel 600, Monel 400, and Hastelloy C 276).  Other materials may be available or offered on request. The inlet ring material can be specified as a different material than the outlet ring material.
  • The PRDI works well in gas or vapor services, as well as liquid or two-phase services.
  • The PRDI may work well in sticky or fouling services, although alternative holder designs such as the TopHat Assembly are recommended in such environments.
  • The PRDI is considered non-torque sensitive. While proper torque procedures should be followed during installation, the PRDI is fairly tolerant of over-torque, or slightly uneven torque of the bolts on the companion flange.
  • The PRDI typically uses a single locater pin, installed by the factory in the inlet ring, to ensure proper rupture disk orientation within the holder assembly. Each rupture disk, manufactured for installation into a PRDI holder, will have a notch punched out of its seating surface to ensure the rupture disk must be oriented correctly, in order to be installed into the PRDI at all.
  • The PRDI is available in ANSI 150#, ANSI 300#, ANSI 600#, ANSI 900#, ANSI 1500#, and ANSI 2500# Flange Classes
  • The PRDI is available in Raised Face, Flat Face, Crush Ring, and RTJ flange facing arrangements.
  • The PRDI can be tapped for instrumentation on both the inlet and outlet rings.
  • The PRDI can be offered as a double disk assembly, allowing for the installation of two rupture disks in series.
  • Kr values are specific to the rupture disk model used. As such, the PRDI does not have its own, unique Kr value.
  • Operating Ratios are specific to the rupture disk model used. As such, the PRDI does not have its own, unique operating ratio.
  • Manufacturing Ranges are specific to the rupture disk model used. As such, the PRDI does not have its own, unique manufacturing range.
  • Burst Tolerances are specific to the rupture disk model used. As such, the PRDI does not have its own, unique burst tolerance.
  • Fragmentation is specific to the rupture disk model used. As such, the PRDI is neither fragmenting nor non-fragmenting.
  • A 1” PRDI has a standard overall height of 1.75”. Custom height PRDI’s are available upon request.
  • A 1.5” PRDI has a standard overall height of 1.75”. Custom height PRDI’s are available upon request.
  • A 2” PRDI has a standard overall height of 1.75”. Custom height PRDI’s are available upon request.
  • A 3” PRDI has a standard overall height of 1.93”. Custom height PRDI’s are available upon request.
  • A 4” PRDI has a standard overall height of 2.31”. Custom height PRDI’s are available upon request.
  • A 6” PRDI has a standard overall height of 2.81”. Custom height PRDI’s are available upon request.
  • An 8” PRDI has a standard overall height of 3.43”. Custom height PRDI’s are available upon request.
  • The factory should be consulted for the overall height of any PRDI above an 8” line size.