Pictured is the standard 150mm pedestal hydrant design as specified by the Hong Kong Water Authority. It is referred to in engineering drawings as the Cast Iron Round Head Fire Hydrant and is manufactured by many companies, domestic and foreign.
The hydrant itself has no valve. Instead, a below grade gate valve inline serves as the main valve. Thailand, Brazil, South Africa, and Fresno, CA, also use the same concept, at least in part of their systems.
Photo: Copyright © 1999, William James