This standard pertains to the various types and classes of wet-barrel fire hydrants for use in fire-protection service in areas where the climate is mild and freezing temperatures do not occur. A wet-barrel hydrant has one or more valve openings above the ground line and, under normal operating conditions, the entire interior of the hydrant is subjected to water pressure at all times. Each outlet nozzle has an independent, compression-type valve (i.e., working with or against the pressure) that controls discharge from that particular outlet. This standard can be referenced in requirements for purchasing and receiving wet-barrel fire hydrants for fire-protection service and can be used as a guide for inspecting and testing wet-barrel fire hydrants. The stipulations of this standard apply when this document has been referenced and only to wet-barrel fire hydrants used in water-supply service.