I have attached a video clip taken from a BFD security cam showing a hydrant gate that failed yesterday while we were doing pumper relay training. An intake on the truck had just been closed and the gate failed.
Fortunately no one was in the path of the flying gate…or this would have been an injury report or possibly worse.
Following the incident we found that the gate failed at the female coupling (cast broke). This gate was on a reserve engine, with the age of the gate unknown (probably more than 20 years old). The gate was made of pyrolite. It appeared that the threads were rounded allowing the gate to “vibrate” when under pressure. With a surge in pressure the gate mostly likely twisted a bit causing the cast to break.
Immediately following this we inspected all our hydrant gates (both the threads and the valve assemblies) and removed 4 from service that have the same thread wear.
It goes to show that when we inspect our equipment, that we really need to be detailed!