RLS-S Assembly

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 ≤ 1.5
  • Suitable for cycling service
  • Vacuum resistant
  • Back pressure resistance can be specified
  • Optional fluoropolymer liner/coating
  • Pressure Equipment Directive “CE” marking and/or other International Certifications
  • BS&B proprietary technology

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

Sizes & Pressures

RLS-S/RLS-ST™ Disk Specifications Minimum/Maximum Pressure with Rating at 72° (22°C)

Disk Size Burst Pressure
psig barg
in mm min max min max
1 25 175 275 12 18.96
1.5 40 145 225 10 15.51
2 50 115 175 7.93 12.06
3 80 75 125 5.17 8.61
4 100 65 100 4.48 6.89

Note: Standard material 316 stainless steel. Other disk sizes, materials and burst pressures are available upon request - consult BS&B. FEP/PTFE liners are available on the process side of the disk in sizes from 2” (50mm) and above. Maximum temperature for 316ss is 750°F (399°C). Maximum temperature for FEP/PTFE is 500°F (260°C).

Burst Tolerance

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


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


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

Bio-Saf Series
Saf-T-Change™ QDR Rupture Disk Replacement System
Burst Alert Sensors
Detec Saf Alarm System - Burst Disk Monitor