Test and Evaluation of Constant Flow Devices for Use in SSN AFFF Proportioning Systems.

Abstract : Constant flow devices, which deliver a constant flow of liquid over a range of upstream and downstream pressures, have been suggested as an alternative to orifice plates for proportioning AFFF in SSN 21 fire suppression systems. Operational and performance characteristics of two light-weight, inexpensive, commercially available constant flow devices have significant advantages over orifice plates. Both models tested, however, showed performance degradation when subjected to simulated service conditions. A constant flow device with improved resistance to wear and to AFFF exposure is desirable. Since the constant flow control devices tested improves proportioning efficiency but do not have optimum characteristics, investigation of improved devices or methods is recommended. Keywords: Fire fighting.