Pressure-Compensating Rupture Disc for Low-Pressure Fluid Containers

Air-permeable rupture for pressure compensation and relief in a single component

  • Pressure-Compensating Rupture Disc for Low-Pressure Fluid Containers. International and US patents pending - © 2021 BS&B Innovations Limited.
    Pressure-Compensating Rupture Disc for Low-Pressure Fluid Containers. International and US patents pending - © 2021 BS&B Innovations Limited.

Many fluids have to be stored and transported in hermetically sealed containers. This keeps them sterile and protects them from environmental influences. Bormann & Neupert by BS&B has developed a new pressure-relieving rupture disc that is also permeable to air and therefore enables pressure compensation as well. This dual-purpose function is ideal for low-pressure fluid containers with a design pressure below that specified by PED and ASME.

Avoiding dangerous pressures

The new eVent is breathable, allowing air to flow and thus compensating several millibars of positive or negative pressure without bursting. This solves a frequent problem in the processing industry, as even minor temperature fluctuations can cause the fluid volume to change significantly. This can lead to dangerous pressures in fully sealed, low-pressure containers. Low-pressure eVent delivers a solution here through atmospheric pressure compensation. Just like conventional rupture discs, it remains free of leaks and requires no maintenance under normal operating conditions.

The eVent activates with high precision only upon reaching the predefined activation pressure, opening up to enable full flow. This protects pressure-sensitive plant components against both damages caused by temperature-related pressure fluctuations and real critical pressures. This dual function is all thanks to a film made from sintered polytetrafluorethylene (PTFE). This material allows air to flow through at low pressure differences of several millibars, while reliably withholding fluids. 

Nominal diameters DN25 and DN150

The developers had to overcome the challenge of ensuring reliable activation at low rupture pressures of around 0.5 bar. The material properties of the PTFE film deliver high production tolerances. The engineers compensated for these by combining it with a thermally stable metal component. This controls the rupture pressure while the PTFE seal ensures pressure compensation. The eVent breathable rupture disc are delivered as a light, integrated assembly ready for installation and in the nominal diameters DN25 and DN150, with a thickness of up to 0.1 millimetres. The thickness and density are determined based on the specific application. The discs are assembled between aseptic connections or conventional pipe flanges.