SAFETY AND EMISSIONS CONTROL
What Type of Bursting Disc?

The quality of bursting discs has improved dramatically in recent years, with the last decade seeing significant research and development going into discs for hygienic and aseptic applications in the pharmaceutical and biotechnology industries. Up until about ten years ago, most discs used in pharmaceutical plants were made from graphite, as they have very low burst pressures and excellent corrosion resistance. Consideration, however, should be given to the fact that they shatter, rather than burst, when operating. As with any fragmenting device, care therefore needs to be taken with system design to avoid downstream problems.

The current trend is now to select non-fragmenting discs, which give the user obvious benefits by avoiding batch contamination and downstream fragmentation. Today’s metallic discs offer superior operating performance over their graphite counterparts, and previous drawbacks of non-availability at lower pressures and low corrosion resistance have been overcome through new designs and the ability to manufacture high-performance products in more unusual materials. These materials facilitate installation in multi-purpose vessels, a practice many chemical and pharmaceutical companies are considering or have already implemented as new plant is installed or existing plant upgraded. Most manufacturers have developed their own unique metal disc types, but they all share a number of core features: low burst pressures, non-fragmenting design, a smooth process side, and all fit directly into industry-standard clamp fittings or in holders between flanges where appropriate. Most are also designed to withstand full vacuum and the rigours of CIP (clean-in-place) procedures.