Reverse Acting Bursting discs are oriented in a system with the process media pressure against the convex side of the disc, placing the rupture disc in compression. As the burst pressure rating of the disc is reached, the compression loading on the rupture disc causes it to reverse, snapping through the neutral position, causing it to open by a predetermined scoring pattern or knife blade penetration. Tension type bursting discs are oriented in a system with the process media pressure against the concave side of the rupture disc. As the burst pressure rating of the disc is reached, the tensile strength of the material is reached, and rupture occurs. ESI would generally recommend using the higher performing reverse acting rupture disc as it has a longer service life.