Wilhelm  Jost  Institut Förderverein e.V.

Maximum explosion pressure and maximum rate of pressure rise



The explosion overpressure pm and the rate of pressure rise dp/dt describe the violence of reaction of dust/air mixtures of random concentration after ignition in a closed vessel. The maximum explosion pressure pmax and the maximum rate of pressure rise (dp/dt)max of combustible dusts are determined in closed standard equipment by means of tests over a wide range of concentration.


The maximum explosion pressure is not volume dependent usually. It accounts for approximately 8 to 10 bar with the most organic gases and steams with air under  atmospheric initial conditions.


The maximum rate of pressure rise depends on the volumen. The product of the maximum rate of pressure rise and the third root of the special volume is constant (Cubic Law) and is called KG-value.

Testing Method:


according to BG Chemie R 003 6/2000 in an 20-L-apparatus or in an 1 m³-vessel

(Further information see also Fire and Explosion Protection)


Safety-relevant meaning:


These datas are needed for the machine interpretation and for constuctional explosion prevention.


Preventive measure

considered safety technial index

Explosion Pressure Resistant Design

maximum explosion overpressure

Explosion Pressure Relief

maximum explosion overpressure, KG-value

Explosion Suppression