There is a vertical fire hydrant in Wisconsin on what is the use of iron
The outdoor cold area should be located in the underground hydrant, otherwise the fire is frozen, not to put out the fire, and will cause the pipeline and Damage Cracking device. Therefore, the bolt should be accompanied by heat measures, in order to ensure its reliability, you can set temperature monitoring, general construction at the same time, buried in the ground.
The suspect is a monitor line for monitoring the temperature of the plug.
This may be a post - monitoring, which is very harmful to fire fighting, but you can destroy the device in case of fire.
