Advanced pressure relief and activation tools

Paul Boughton

Roger Bours outlines the latest developments in rupture disc engineering.

When it comes to rupture discs, a ‘one size fits all’ approach is not the best guarantee for success. Although many projects can simply opt for off-the-shelf solutions, for certain (more complex) projects, it pays huge dividends to consider each particular application and its requirements separately in order to devise a more tailored approach.

An expert in this arena is Fike, which offers a wide range of standard rupture discs. Where an application demands a different approach, it has experienced engineers and technical staff on-hand to assist. 

Flexibility of design, a wide range of materials and extensive rupture disc engineering expertise mean the company is capable of building the precise products for sealing, venting, small space, pressure relief valve protection or other special requirements. Fike begins by gathering as much information as possible about the application needs. Its engineers consider all of the performance factors, including type of pressure relief application, operating conditions, inlet/outlet configurations, activation specifications and special processes. Critical factors from response time and leakage requirements are all examined to meet the specific needs required.

Due to the critical nature of some applications, special testing procedures and equipment can be used to accurately simulate the rupture disc application conditions. Fike has a comprehensive programme of destructive and non-destructive tests, and uses its own ASME-certified Flow Characterisation Lab to test and certify custom products and solutions.

Custom performance capabilities encompass: 

*  Activation Pressures: 0.5 – 100,000 PSIG (0.03 barg – 6900 barg) depending on size, flow requirements and material of construction

* Back Pressure: Several times the rated set pressure

* Operating Temperature: -320° F to 1,000° F (-196°C to 600°C) where higher temperatures need to be countered with special heat reduction

* Tolerance on Set Pressure: ± 2% to ± 5%

* Unobstructed opening

* Critical Leakage: Most do not exceed 1 x 10-8 cc Helium/sec

* Operating Pressure: As high as 95% of the set pressure

An example of a dedicated pressure relief design solution requiring critical performance and the highest reliability can be seen in a rather high profile project that Fike undertook.

On May 16, 2011, the space shuttle Endeavour lifted off on its final mission – the penultimate mission of the entire shuttle programme – and subsequently docked with the International Space Station (ISS) on May 19. Part of the Endeavour’s mission was to deliver the Alpha Magnetic Spectrometer (AMS-02), which included several Fike rupture discs, to the ISS.

The AMS-02 is a state-of-the-art particle physics detector that is designed for a 10-year study to search for anti-matter and to collect data to determine long-term variations of cosmic ray composition and flux. These observations will be used to attempt to answer fundamental questions about our universe regarding the existence of dark matter and to improve our understanding of the origin of cosmic rays and their propagation through our solar system. 

High-precision pressure relief

As part of the AMS-02 project, Fike rupture discs featuring G2 technology were selected to provide overpressure protection of discrete volumes for the cryomagnetic system’s helium and vacuum  vessel. G2 is a sophisticated technology used to manufacture rupture discs without hard-score tooling, producing no stress zones that can fatigue and offering premium performance. The result is a low-pressure rupture disc solution featuring tight burst tolerances and extremely high operating ratios. In addition, the advanced automation significantly increases consistency and provides for fast, economical delivery time. 

These high-precision pressure relief devices are used to prevent pressure excursions above the maximum design pressure (MDP) of subsystems of the AMS-02 Cryogenic system, including the vacuum case, superfluid helium tank and cryogenic plumbing system during the complete duration of the programme. 

Any uncontrolled events would be catastrophic for flight safety.

Though it’s exciting to be part of such an extraordinary project, this is not the first time Fike pressure relief products have been in space. 

The company’s rupture discs were specially designed for use on astronaut oxygen supply systems, emergency inflation devices and within the engine powering the space shuttle itself, to name just a few applications. 

Fike offers a complete line of cost-effective rupture discs, holders and pressure relief devices that are compliant with global code regulations and designed to meet or exceed industry requirements for performance, reliability and quality. And when unique situations such as the AMS-02 project demand a different approach, Fike’s experienced engineers and technical staff explores each requirement to develop the perfect solution.

For expert advice

The company is an experienced, trusted expert in rupture disc technologies, explosion protection, pressure activation, fire alarm systems and fire suppression solutions. In addition to its manufacturing facilities in the USA, Belgium, Wales, Canada and India, Fike has sales   and service offices throughout North and South America, Europe, Asia and the Middle East. 

For more information at

Roger Bours is director, Pressure Relief at Fike in Belgium.

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