Which foam proportioning method is NOT specified by NFPA 11?

The method identified as not specified by NFPA 11 is indeed the high-pressure nozzle. NFPA 11 outlines various foam proportioning methods, including pressure proportioners and pump-type proportioners, as these are essential for ensuring proper mixing and application of firefighting foam. These methods have specific operational parameters and guidelines to ensure effectiveness in suppressing flammable liquid fires.

The high-pressure nozzle does not fall under the category of foam proportioning methods recognized by NFPA 11 because its primary focus is on the delivery of water under high pressure rather than the accurate proportioning and mixing of foam concentrates with water. While high-pressure nozzles may be used in various firefighting systems, they do not provide a controlled method for incorporating foam into the water stream, which is crucial for effective firefighting with foam agents.

In the context of the other choices, pressure proportioners and pump-type proportioners are specifically designed to mix foam concentrate with water at predetermined ratios, ensuring that the foam is effective when deployed. Coupled-water motor pumps are also designed to integrate with standard systems for proportioning foam, emphasizing their importance in the overall firefighting strategy as outlined by NFPA standards.