Taiwan Provincial Standard of the People's Republic of China
Latest
CNS 12933-1995
Scope
This standard applies to outdoor fire hydrants and their general technical regulations. There are two types of outdoor fire hydrants: forward pressure type and reverse pressure type. 1.1 Sequential pressure type: The opening direction of the main valve is the same as the direction of water flow. 1.2 Back pressure type: The opening direction of the main valve is opposite to the direction of water flow.