SKr™ Reverse Buckling Rupture Disk

Performance Features

  • Designed for gas, liquid and multi-phase service
  • Suitable for operating pressure to 90% of the marked burst pressure (95% of the minimum)
  • Designed for non-fragmentation, recommended for relief valve isolation
  • Damage safety ratio ≤ 1
  • Suitable for cycling service
  • Vacuum resistant
  • Available with ASME “UD” (select 0%, -5%, -10% Manufacturing Design Range)
  • Pressure Equipment Directive “CE” marking and/or other International Certifications. Patent 6321582, 6178983, 6446653, 5996605 apply/pending

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  • Sizes & Pressures
  • Burst Tolerance
  • Safety Heads & Sensors
  • Accessories
  • Documentation

Sizes & Pressures

SKr™ Disk Specifications Minimum/Maximum Pressure with Rating at 72° (22°C)

Disk Size Nickel Alloy 200 Monel® Alloy 400 Inconel® Alloy 600 Hastelloy® Alloy C-276 and 316SS Tantalum Titanium
in mm psig barg psig barg psig barg psig barg psig barg psig barg
min max min max min max min max min max min max min max min max min max min max min max min max
0.75 20 55 500 3.79 34.47 60 500 4.14 34.47 60 500 4.14 34.47 60 500 4.14 34.47 55 500 3.79 34.47 90 500 6.20 34.47
1 25 55 500 3.79 34.47 60 500 4.14 34.47 60 500 4.14 34.47 60 500 4.14 34.47 55 500 3.79 34.47 90 500 6.20 34.47
1.5 40 40 500 2.76 34.47 45 500 3.10 34.47 45 500 3.10 34.47 45 500 3.10 34.47 40 500 2.76 34.47 60 500 4.14 34.47
2 50 25 500 1.72 34.47 30 500 2.07 34.47 30 500 2.07 34.47 30 500 2.07 34.47 25 500 1.72 34.47 35 500 2.41 34.47
3 80 20 500 1.38 34.47 22 500 1.52 34.47 22 500 1.52 34.47 25 500 1.72 34.47 20 500 1.38 34.47 25 500 1.72 34.47
4 100 16 500 1.10 34.47 18 500 1.24 34.47 18 500 1.24 34.47 20 500 1.38 34.47 16 500 1.10 34.47 20 500 1.38 34.47
6 150 15 261 1.03 18.00 15 261 1.03 18.00 15 261 1.03 18.00 20 261 1.38 18.00 15 261 1.03 18.00 20 261 1.38 18.00
8 200 15 150 1.03 13.79 15 200 1.03 13.79 15 200 1.03 13.79 20 200 1.38 13.79 15 200 1.03 13.79 20 200 1.38 13.79
10 250 11 150 0.76 10.34 11 150 0.76 10.34 11 150 0.76 10.34 11 150 0.76 10.34 15 150 1.03 10.34 20 150 1.38 10.34
12 300 9 110 0.62 7.58 9 110 0.62 7.58 9 110 0.62 7.58 9 110 0.62 7.58 15 110 1.03 7.58 20 110 1.38 7.58
24 600 Consult BS&B

Note: Hastelloy® is a trademark of Haynes International Inc. Monel® and Inconel® are registered trademarks of Special Metals Corporation and its subsidiaries. Other materials available on request.

Burst Tolerance

Marked Burst Pressure Burst Tolerance
≤ 40 psig (2.76 barg) ± 2 psig (0.138 barg)
> 40 psig (2.76 barg) ± 5%

Accessories

BS&B supplies many of the Accessories required to safely and conveniently install our overpressure relief devices and complementary products. Through our professional team and global network of sales engineers and procurement personnel, we are able to provide the highest quality accessory products to meet your installation requirements.

Saf-T-Change Quick Disk Replacement (QDR)

After activation, the replacement disk is quickly slid into place. Saving hours of lost production due to blown rupture disks.

Tell-Tale Assemblies & Excess Flow Valves/Gauges

A gauge tap in the outlet flange of the safety head may be considered when the safety head is installed in a vertical position.

Spare Safety Heads & Cap Screws

Jackscrews

When activated, the jackscrews effectively separate the flanges, providing adequate clearance to remove or insert a safety head and external gaskets.

Lifting Lug Eye Bolts

Eye bolts are recommended when weight and/or accessibility is a factor in lifting safety heads.

Baffle Plate

When a safety head is free-vented to atmosphere, a baffle plate may be considered to disperse overpressure and absorb recoil.

Product Literature

Sta-Saf System Brochure
SKr™ Rupture Disk Brochure
Burst Alert Sensors Brochure

Installations

Sta-Saf™ System Installation Instructions
Sigma EXL™, Sigma™, SKR™, and LPS™ Installation Instructions

Overview

The SKr™ Reverse Rupture Disk (Bursting Disc) is designed with a circular score line located at the edge of the domed area, on the downstream side of the disk. At the marked burst pressure, the disk's dome reverses and opens by shearing around the circular score line. The SKr™ Reverse Rupture Disk (Bursting Disc) uses SAF- technology (Structural Apex Forming) enabling very low burst pressures to be achieved with excellent opening characteristics. An integral energy absorbing hinge located on the downstream side of the disk enables the SKr™ Reverse Rupture Disk (Bursting Disc) to perform in gas or liquid service with superior flow performance. The hinge design interacts with the Safety Head bore to retain the SKr™ Reverse Rupture Disk (Bursting Disc) on opening, avoiding fragmentation

SKr™ Reverse Rupture Disk (Bursting Disc) Material Options

The SKr™ Reverse Rupture Disk (Bursting Disc) is available in 316SS, Nickel Alloy 200, Monel Alloy 400, lnconel Alloy 600, Hastelloy Alloy C276, Titanium and Tantalum. A competent person should select the disk material that is chenmically resistant to the application. Corrosion of the disk material will affect its performance and may result in premature bursting or leakage through the disk. All standard disks are available with 0%, 5%, and 10% manufacturing ranges. For assistance in disk material selection contact BS&B Safety Systems, Inc. or BS&B Safety Systems Ltd.

 

Flow Performance

The SKr™ Reverse Rupture Disk (Bursting Disc) has been specifically developed to produce superior flow performance at all burst pressures in gas or liquid service. The circular score on the disk's dome, coupled with the non-restrictive hinge on the outlet side of the disk, ensures an excellent pressure relief opening.

Flow Resistance Factor Kr may be used to determine the relieving capacity of a system according to the ASME and CEN (pending) codes. Individual Kr values have been established for both gas and liquid service for the SKr disk. Minimum Net Flow Area (MNFA) for each disk size is provided to assist with ASME sizing calculations. Net Relief Area (NRA) for each size disk is provided to assist with European code sizing calculations.

 

Installation in SRB-7RS™ Safety Head

The SKr™ Reverse Rupture Disk (Bursting Disc) installed in an SRB-7RS™ Safety Head permits the correct torque to be applied in the workshop before installation into the process. The asymmetric locating pins ensure centering and orientation of the disk within the Safety Head. The performance-proven metal-to-metal 'bite type' seal in the Safety Head (2"/50mm size and above) assures a leak tight assembly. When installed properly into the SRB-7RS™ Safety Head, the assembly can be removed, inspected, cleaned carefully then reinstalled without replacing the disk as the pretorque capscrews maintain the clamp load on the disk.