Considerations regarding the determination of explosion pressure at normal ambient temperature, compared to explosion pressure determination at ambient temperatures below – 40°C, for flameproof enclosure

National Institute for Reasearch and Development in Mine Safety and Protection to Explosion – INSEMEX Petroșani, 32-34 G-ral. Vasile Milea street, Petroşani, Hunedoara county, Romania

^* Corresponding author: mihai.magyari@insemex.ro

Abstract

Flameproof enclosures (also known as explosion proof or Ex d enclosures) are critical safety components in hazardous environments where explosive atmospheres may exist. Their primary function is to contain an internal explosion without allowing the ignition to propagate to the external atmosphere. A key parameter in designing and certifying these enclosures is the maximum internal explosion pressure (P max) that the enclosure must withstand. This article explores the determination of explosion pressure under two specific ambient temperature conditions: 1. Normal ambient temperature range (typically – 200C to + 400C), and 2. Extremely low ambient temperatures, particularly below – 400C, which are often encountered in arctic or high altitude environments. The paper also presents some results obtained in our test laboratory, on a test sample (two configurations) with the explosion pressure determined for two different ambient temperatures (normal temperature and ambient temperature of -40 °C) and two different explosive mixtures (ethylene & hydrogen) selected according to standard IEC 60079-1.