Is the nozzle (where the flame exits) of PF13L160 brass? Similar to this: https://www.amazon.com/dp/b002agx7g6/?coliid=i1qwsqxrmmofdi&colid=2hdpjqc5mcscp&psc=0
The main burner is of cast iron. The pilot is of brass. Based upon our experience, brass nozzle for the main burner will experience deformation over its life much easier since the intense heat from the main burner. The brass nozzle for the pilot is OK as it is usually in low flame usage mode. Hope this helps.