OsecoElfab’s LoKr Rupture Disc

OsecoElfab manufactures the LoKr rupture disk, which is a high-performance, reverse acting rupture disc designed and manufactured for extremely demanding rupture disc applications.  The LoKr features the lowest KR in the industry for a reverse acting disc.  The disc is circumference-scored after the forming of its low crown, followed by the application of a precision dimple in the center of the dome. This process yields a high-performance disc able to withstand high operating pressures within the most difficult applications. The LoKr offers a smooth non-scored surface on the process side. This limits product accumulation on the disc and reduces the risk of polymerization and crystallization of media on the disc surface. The low KR value and high reliability make the LoKr an excellent choice for isolation of safety relief valves.

  • The LoKr is available in line sizes ranging from 1 inch diameter all the way up to 12 inches diameter.
  • The LoKr is available in burst pressures ranging from 10 psig all the way up to 2500 psig.
  • The LoKr is available in burst temperatures ranging from cryogenic temperatures all the way up to 1000 degrees F.
  • The LoKr 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 LoKr works well in gas or vapor services, as well as liquid or two-phase services.
  • The Kr value for the LoKr, when opened by any fluid phase is Krgl = 0.22.
  • The LoKr has a 95% operating ratio, meaning the LoKr operates reliably and with a long service life at pressures up to 95% of the marked burst pressure.  Pressure excursions above this 95% operating ratio will shorten the lifespan of the LoKr.
  • The LoKr is only offered with a 0% Manufacturing Design Range (MDR), meaning there will never be any variation between what burst pressure you order, and what burst pressure is marked on the tag of the rupture disk.
  • The LoKr maintains or exceeds the ASME-specified burst tolerances of +/- 5% of marked burst pressure for burst pressures above 40 psig, or +/- 2 psig for burst pressures at or below 40 psig.
  • The LoKr is a scored metal rupture disk, with a non-fragmenting design, meaning the LoKr can be installed upstream from a pressure relief valve.
  • The LoKr does not have a vacuum support.  The LoKr is designed to handle vacuum services without any additional design enhancements.
  • The LoKr is a reverse acting metal rupture disk.  Process pressure is applied to the convex side of the rupture disk.  Increasing process pressure collapses the dome of the rupture disk until the dome inverts, and the metal yields and tears open along the scored lines.
  • The LoKr, like all reverse acting metal rupture disks, does best in static pressure applications, but also handles pressure cyclic services extraordinarily well. The LoKr has been tested in excess of 1,000,000 full scale pressure cycles (0 psig to 95% of marked burst pressure and back down to 0 psig again), with no evidence of fatigue induced failure or alteration of burst pressure.
  • The LoKr is offered with a PFA liner or shield on the inlet side of the rupture disk, to enhance corrosion protection.  This configuration is called the LoKr-L
  • The LoKr is designed, manufactured, and certified to ASME BPVC Section XIII requirements.
  • The LoKr is designed to pair with the LKR insert holder, as well as the LKR-P pretorqued insert holder, as well as the Safety Cartridge one-piece holder assembly.
  • The MNFA for a 1.0″ LoKr is 0.864 square inches
  • The MNFA for a 1.5″ LoKr is 2.036 square inches
  • The MNFA for a 2.0″ LoKr is 3.355 square inches
  • The MNFA for a 3.0″ LoKr is 7.393 square inches
  • The MNFA for a 4.0″ LoKr is 12.73 square inches
  • The MNFA for a 5.0″ LoKr is 28.89 square inches
  • The MNFA for a 6.0″ LoKr is 50.0 square inches
  • The MNFA for a 10.0″ LoKr is 78.9 square inches
  • The MNFA for a 12.0″ LoKr is 111.9 square inches
  • For a 1.0” LoKr, the minimum burst pressure for all the standard OE materials (316 Stainless Steel, Nickel 200, Inconel 600, Monel 400, and Hastelloy C 276) is 15 psig. 316 Stainless Steel has a maximum burst pressure of 2000 psig.  Nickel 200 has a maximum burst pressure of 1750 psig,  Inconel 600 has a maximum burst pressure of 2000 psig.  Monel 400 has a maximum burst pressure of 2000 psig.  Hastelloy C 276 has a maximum burst pressure of 2500 psig.
  • For a 1.5” LoKr, the minimum burst pressure for all the standard OE materials (316 Stainless Steel, Nickel 200, Inconel 600, Monel 400, and Hastelloy C 276) is 10 psig. 316 Stainless Steel has a maximum burst pressure of 1500 psig.  Nickel 200 has a maximum burst pressure of 1000 psig,  Inconel 600 has a maximum burst pressure of 1500 psig.  Monel 400 has a maximum burst pressure of 1300 psig.  Hastelloy C 276 has a maximum burst pressure of 2200 psig.
  • For a 2.0” LoKr, the minimum burst pressure for all the standard OE materials (316 Stainless Steel, Nickel 200, Inconel 600, Monel 400, and Hastelloy C 276) is 10 psig. 316 Stainless Steel has a maximum burst pressure of 1200 psig.  Nickel 200 has a maximum burst pressure of 1000 psig,  Inconel 600 has a maximum burst pressure of 1500 psig.  Monel 400 has a maximum burst pressure of 1200 psig.  Hastelloy C 276 has a maximum burst pressure of 2200 psig.
  • For a 3.0” LoKr, the minimum burst pressure for all the standard OE materials (316 Stainless Steel, Nickel 200, Inconel 600, Monel 400, and Hastelloy C 276) is 10 psig. 316 Stainless Steel has a maximum burst pressure of 1200 psig.  Nickel 200 has a maximum burst pressure of 1000 psig,  Inconel 600 has a maximum burst pressure of 1500 psig.  Monel 400 has a maximum burst pressure of 1200 psig.  Hastelloy C 276 has a maximum burst pressure of 2000 psig.
  • For a 4.0” LoKr, the minimum burst pressure for all the standard OE materials (316 Stainless Steel, Nickel 200, Inconel 600, Monel 400, and Hastelloy C 276) is 10 psig. 316 Stainless Steel has a maximum burst pressure of 1200 psig.  Nickel 200 has a maximum burst pressure of 1000 psig,  Inconel 600 has a maximum burst pressure of 1500 psig.  Monel 400 has a maximum burst pressure of 1200 psig.  Hastelloy C 276 has a maximum burst pressure of 1500 psig.
  • For a 6.0” LoKr, the minimum burst pressure for all the standard OE materials (316 Stainless Steel, Nickel 200, Inconel 600, Monel 400, and Hastelloy C 276) is 10 psig. 316 Stainless Steel has a maximum burst pressure of 750 psig.  Nickel 200 has a maximum burst pressure of 600 psig,  Inconel 600 has a maximum burst pressure of 750 psig.  Monel 400 has a maximum burst pressure of 750 psig.  Hastelloy C 276 has a maximum burst pressure of 750 psig.
  • For a 8.0” LoKr, the minimum burst pressure for all the standard OE materials (316 Stainless Steel, Nickel 200, Inconel 600, Monel 400, and Hastelloy C 276) is 10 psig. 316 Stainless Steel has a maximum burst pressure of 600 psig.  Nickel 200 has a maximum burst pressure of 500 psig,  Inconel 600 has a maximum burst pressure of 600 psig.  Monel 400 has a maximum burst pressure of 600 psig.  Hastelloy C 276 has a maximum burst pressure of 750 psig.
  • For a 10.0” LoKr, the minimum burst pressure for all the standard OE materials (316 Stainless Steel, Nickel 200, Inconel 600, Monel 400, and Hastelloy C 276) is 10 psig. 316 Stainless Steel has a maximum burst pressure of 400 psig.  Nickel 200 has a maximum burst pressure of 250 psig,  Inconel 600 has a maximum burst pressure of 400 psig.  Monel 400 has a maximum burst pressure of 400 psig.  Hastelloy C 276 has a maximum burst pressure of 500 psig.
  • For a 12.0” LoKr, the minimum burst pressure for all the standard OE materials (316 Stainless Steel, Nickel 200, Inconel 600, Monel 400, and Hastelloy C 276) is 10 psig. 316 Stainless Steel has a maximum burst pressure of 300 psig.  Nickel 200 has a maximum burst pressure of 300 psig,  Inconel 600 has a maximum burst pressure of 300 psig.  Monel 400 has a maximum burst pressure of 300 psig.  Hastelloy C 276 has a maximum burst pressure of 300 psig.