Anaheim, CA --- Electron Beam Engineering, Inc. announces that it has supported BS&B Safety Systems with significant improvements in the welding of its rupture disks. “Before we got involved, BS&B was conventionally welding, clamping, or gluing its rupture disks,” said Richard Trillwood, CEO of Electron Beam Engineering (EBE). “Because of our precision electron beam welding and the low amount of heat generated, our process produces less distortion and minimal effect on the burst disk material resulting in a much better product and is ideal for special materials and designs. Additionally, our process requires no post weld machining or cleanup. The outcome is a manufacturing procedure that is more predictable resulting in a higher yield of disks all having the same burst pressure.”
Rupture disks, also known as pressure safety disks, are a sensitive relief device designed to instantaneously rupture at a predetermined pressure and temperature as a means of providing protection for personnel, electronics, and equipment. Rupture disks can respond within milliseconds to an increase or decrease in pressure and temperature, but once the disk is ruptured it will not reseal. Rupture disks are commonly used in petrochemical, aerospace, medical, pharmaceutical, food processing, and oil field applications. They can be used as a single protection device or as a backup device for a conventional safety valve. If the system pressure reaches an unsafe level and the safety valve fails, the rupture disk will burst.
The sonobuoy, a good example of a BS&B rupture disk application, is a small buoy that contains an expendable sonar system and is usually dropped from an aircraft as part of anti-submarine warfare or for underwater acoustic research.
A rupture disk is used as part of the activation manifold system to keep the electrolyte separated from the battery cells in the reserve battery. The sonobuoy could remain unused, in storage, for up to 20 years. When deployed from an aircraft a signal would trigger a squib (small explosive device) to open the rupture disk allowing the electrolyte to energize three battery cells through three tubes. There is a total of six pieces in the sonobuoy rupture disk assembly and all of them are 316L stainless steel.
Another frequent use of burst disks is for fire suppression, like sprinklers. A fire suppression gas, which has been specifically developed as a clean agent to not be harmful to people or the atmosphere, is instantly released through the rupture disk when a sensor signals that an emergency condition is reached. The same principle is used for automobile airbags, one of the biggest applications for rupture disks. “Years ago EBE welded rupture disks used in the landing system of the Mars Rover,” added Trillwood. “There were three different rupture disks involved for the airbag system, landing shoot, and air shoes.” After parachutes slowed the landing capsule, rupture disks were burst to deploy air bags that surrounded the lander like a bunch of giant beach balls. Because the atmosphere on Mars is not nearly as thick as on earth, the parachutes could not slow the vehicle down enough to land safely. The air bags allowed the Rover to bounce on the surface of Mars several times and eventually would come to rest. Titanium was required for this application because of its light weight and high strength.