What is the difference between high / and low pressure water mist systems?
High pressure and low pressure systems are tested and approved to the same standards, and systems being approved in accordance with the test standards do also in general have comparable fire fighting capability within the type of occupancies, which the approval standards cover. The difference between high / and low pressure water mist systems is primarily to be found in the “nozzle” designs where different means of atomising water require different water pressures. The different designs of “water mist nozzles” and the required water pressures set different requirements to water/gas supply, pump, control, and piping for low pressure and high pressure systems. Comparisons of typical parameters between high and low pressure systems are given in the table below. The actual system parameters depend on system brands and designs. • Typical Parameters • High Pressure Systems • Low Pressure Systems • Approval test standards and acceptance criteria (NFPA, CEN, FM Approvals, etc.) • The same as f
