The Model BP420 burst plugs are designed specifically for use in plastic extrusion systems. Burst Plugs (also known as rupture disks) are designed for reliable, emergency relief of excess pressure in a system. The Model BP420 will instantaneously rupture at a specific, predetermined pressure and temperature. Each one piece assembly consists of a 304 stainless steel body with a welded Inconel rupture disk. The disk is flush with the tip of the burst plug with no cavity for product build up. A burst plug may be specified for primary relief in applications where pressure build-up can occur so rapidly that the response time of a relief valve is inadequate,such as in a polymerization reaction vessel. All burst plugs are tested at rated burst pressure and temperature. In addition, markings on the burst plugs are laser engraved and more visible, and each burst plug is labeled and shipped in a protective package.