See GB50974-20 14 Technical Specification for Fire Water Supply and Fire Hydrant System 3.5 for details. Mainly look at the volume v of the library, and you can roughly calculate its volume.

5000 < V ≤ 10000 cubic meters, three water guns should be used at the same time;

10000 < v ≤ 25000m3, and five water guns should be used at the same time;

V > 25,000 cubic meters, 8 water guns should be used at the same time.