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Unit 19, 77 Bourke Road, Alexandria, NSW 2015 AUSTRALIA

Marston – RBX Rupture Disc / Holder Assemblies

The Marston RBX reverse buckling disc incorporates a precise scoring adjacent to the dome. When the disc is subjected to excessive pressure the dome inverts, bursts, and opens along the scored groove without fragmentation making it an ideal disc for the upstream protection of safety relief valves, particularly as its open height, unlike circumferentially grooved discs, is only half of the disc Nominal Bore.

The Marston RBX disc has a smooth process side surface which minimises the likelihood of product deposition and build-up.

The RBX can be designed for steam, gas, and certain liquid applications and are suitable for operating ratios of up to 95% of minimum bursting pressure.



Fragmentation: None
Operating Ratio: Up to 95%
Vacuum Duty: Generally Full Vacuum
Pressure Cycling Duties: Excellent
Leak Tightness (To Vent): <1 x 10-6 mbar.l.sec-1
Leak Tightness (To Atmosphere): <1 x 10-5 mbar.l.sec-1


Marston is fully committed to an ongoing Total Quality Improvement programme. This was recognised with Marston audited and approved to design and manufacture bursting discs with its Quality Control procedure registered to the highest standard required by BS EN ISO 9001 Certification.

Quality is an integral part of all processes to provide customer satisfaction and confidence.

RBX bursting discs are manufactured and tested in accordance with the requirements of the relevant standard, including BS 2915, AD Merkblatt A1, ISPE SL, ASME VIII, ISO 6719, and EN ISO 4126.

All of the Marston standard disc designs have been approved for use in accordance with the requirements of the P.E.D., 97/23/EC.

Corrosion Resistance:

RBX bursting discs can be manufactured from all commonly used disc materials, including Tantalum, Nickel alloys, and Stainless Steel. Fluorocarbon lining or coating can also be considered when selecting for a corrosive duty.


Standard tolerance on all RBX bursting discs are ± 5%. Improved tolerances may be available, please contact us for further assistance.

The Effect of Temperature:

Changes in temperature affect all bursting disc materials. Typically, as the temperature rises, the material strength reduces and the bursting pressure falls.

Reverse buckling discs depend on dome profile as well as the material thickness to determine the bursting pressure. The temperature effect varies with dome profile. It is therefore not possible to give typical temperature effects for reverse buckling bursting discs. The effect is established at the time of ordering and is stated on the bursting disc test certification.

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