Retrotec Design and Evaluation for Peak Pressure and Agent Retention Time - Manual

SP710 Page 1 of 4 rev-2010-07-14
Design and evaluation for peak pressure and agent retention time
Peak Pressure Damage
Damage caused by peak pressures is a huge potential liability that clean agent system installers
must deal with. During a clean agent discharge, the enclosure must have sufficient leakage to
prevent excessive pressures from building, but be tight enough to satisfy retention time
requirements.
The graph shown below is actual data recorded from a static pressure probe during a discharge
test. The maximum pressure reached here is equivalent to about 20 pounds per square foot,
which is double the "specified enclosure pressure limit" for most enclosures.
Excessive peak pressure is normally resolved by the installation of a pressure relief vent but no
comprehensive research had been done to determine the exact amount of venting required,
until now. Retrotec has just completed a five-year study along with Fike, 3M, Ansul, Kidde-
Fenwal, DuPont, Tyco, and Chemetron in which four inert agents and four halocarbons were