Overpressure

Under blast ( PEXP ) refers to the under specified conditions pressure which occurs in a closed room at the explosion in an explosive environment at a specific composition. The explosion pressures are gauge pressures thereby relative to the atmospheric pressure (1 bar).

Prospective explosion pressure

Prospective explosion pressure ( perw ) is the maximum pressure that can occur in a piece of equipment at a realized protection concept ( under the given plant, processes and all operating parameters and states ). The expected explosion pressure can not be higher than the maximum explosion pressure ( pmax ), unless it is in the system, a pressure exists, which is higher than the atmospheric pressure (1 bar).

Maximum explosion pressure

The maximum explosion pressure is defined as the highest measured explosion pressure at above given requirements.