BS&B Rupture Disks

BS&B Reverse Buckling Rupture Disks

The Reverse Buckling disk represents the best in rupture disk (bursting disc) technology. Invented by BS&B, our range of reverse buckling products provides a pressure relief solution for burst pressures ranging from a few inches of water column / a few millibar to over 70,000 psig / 4800 bar.

Burst pressure is accurately controlled by a combination of material properties and the shape of the disk domed structure. By loading the Reverse Buckling disk in compression it is able to resist operating pressures up to 100% of minimum burst pressure even under pressure cycling or pulsating conditions.

Designed for non fragmentation upon activation, Reverse Buckling disks are recommended for combination with pressure relief valves to isolate them from normal process conditions ensuring excellent leak tightness, reduced valve maintenance expenses and often allowing the use lower cost valve trim.

The Sta-Saf® family of Reverse Buckling Disks includes the S90™, SKr™, RLS™, JRS™, FRS™, and Sigma EXL™ disks. Standard Features of the Sta-Saf® family are:
• 90% or greater operating ratio relative to ASME or CE
• Vacuum resistant
• Solid metal construction enabling optimum leak tightness
• Designed for nonfragmentation
• Recommended for isolation of pressure relief valves
• Metal tag with product identification and traceability data, as well as code symbol stamps as appropriate

• The Sure-Saf® CSI™ - uses SAF technology (structural apex forming), which enhances accuracy of burst pressure
LPS™ - provides low burst pressures from 5 psig (0.35barg)
RB-90™ - provides overpressure protection by reversing and snapping against precision stainless steel knife blades
Eco-Saf® ECR™ - offers the lowest burst pressures available from a reverse buckling disk; The disk relieves overpressure or vacuum
by reversing and opening at the perimeter of the dome
SVI™ - a single-use rupture disk assembly (no holder required) for isolating safety relief valves; For retrofit with fixed piping
SKR-U™ - an all purpose SKR rupture disk partnered with a threaded union-type holder


The BS&B SRB-7RS is the original pre-torqued Safety Head designed for reverse buckling rupture disks. The SRB-7RS allows proper clamping of a Rupture Disk to be completed before installation between companion flanges. This holder offers the advantage that an installed disk may be taken out of service, inspected, cleaned (if appropriate) and reinstalled provided the cap screws are not loosened and the torque value is maintained.
A J-bolt ensures the Safety Head is fitted in the required direction between companion flanges by engaging a blind hole drilled on the inlet companion flange perimeter. The J-bolt provides a constant visible signal of correct installation.
Providing multiple pipe flange compatibility, the SRB-7RS fits pipe flanges conforming to a wide range of International Standards, including ANSI, DIN, BS, AFNOR, UNI and JIS. BS&B suggests the use of Fluoropolymer coated capscrews (blue color) for enhanced corrosion protection.
Other features of the SRB-7RS include.
• Three asymmetric locating pins ensure centering and correct orientation of the disk within the Safety Head
• A "bite-type" seal for sizes 2" (50mm) and larger engages with the disk flange creating a metal-to-metal 'bubble tight' seal
• Maximized flow with full circular opening
• Flow arrows indicate direction of flow


The Type TR™ Series Torque Resistant Safety Head offers the identical performance and flow characteristics valued from standard BS&B safety heads. The only difference – the TR Series Safety Heads were designed with a wider seating surface. This distinct safety feature protects rupture disks from situations where plant personnel may overtorque rupture disks within piping systems, or when using spiral wound gaskets.


The SRI-7RS Safety Head is a new safety head from BS&B designed to use standard hex head cap screws to apply torque to the safety head. The cap screws are visible and accessible which allows the user confirmation of their presence and verification of applied torque in service. The BS&B signature ‘bite-seal’ is present in all nominal sizes, optimizing leak tightness. The unique shape of the SRI-7RS safety head is self-centering inside the companion flange bolt circle to maximize flow. It also has lower mass than the SRB-7RS safety head.

We provide on-site training programs include "Advanced Maintenance Workshops" covering:

  • Rupture disk technology
  • Selection, sizing and specification
  • Installation and maintenance procedures
  • Safety considerations
  • Field event analysis
  • Individual site considerations
  • Explosion vent technology
  • Buckling pin technology

Contact us to set up a Seminar

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