What is the over pressure relief valve?

Our regulators have an over pressure relief valve. If this operates, the over pressure exits the regulator via the upper chamber breather orifice, the 90° plastic nozzle is screwed into this orifice. 

 

Our manufacturing standard requires we supply this nozzle as a means to help prevent water ingress into the upper regulator chamber, therefore the nozzle is best directed away from any potential water ingress. The nozzle also helps maintain that the orifice remains clear from any blockage. In a very exposed location a short hose length could be added to aid this.