Within a pyrotechnic plant, a deflagration occurred during the compression loading of fireworks jets. Though half the plant’s daily production of fireworks jets had already been completed (i.e. 50 in all), the technician stationed in the adjacent premises heard a loud noise and saw a glow. A compression of the preparation (composed of magnesium, nitrate and the chemical lucovyl) was underway and had reached the final phase when the fire struck, causing a blast impact and creating a fireball. The automatic quenching device operated successfully; no injuries were reported and the machinery was only partially damaged. All unfastened parts wound up being ejected.

The compression process created significant mechanical loadings capable of generating friction or jamming, which in turn caused the explosion. The operator proceeded by:

• reassessing the choice of oil for lubricating tubes by focusing on its viscosity and resistance characteristics over time;
• revising the tube phosphatation;
• defining acceptable wear tolerances for the punch, matrix and guide, in addition to scheduling a periodic inspection;
• setting up an accurate position sensor for the machinery controlling cycle initiation.