Nozzle with metal rotor and stator have to withstand extreme forces. The material used and the surface treatments performent should prolong the lifetime. The very high precision required for a quality rotary nozzle are constricting the suitable materials. The corrosion resistance is therefore second in line.
To maintain this fragile design it is important to implement the right maintenance procedures. Use clean, filtered water to operate. Water should only come in contact with the nozzle when used. Water trapped inside the nozzle from use, but also from condensation caused by the changing air temperature, has to be removed. To have it dried is not enough as it can clock up and still cause galvanic corrosion. Do not use any oil. Oil may have additives and will dry out. A restarting might not be possible or only with a limited water film causing premature nozzle failure. If ceramic insert are used you can not use aggressive liquids. The ceramic is usually sealed in the housing with a sealant. Do not use mechanical forces to get a rotor turning. Marks from a screw driver on stator or rotor make a nozzle irreparable.
The fluid has to have the following characteristics:
-extreme creep-ability
-dispels water (water repellent)
-corrosion protection
-lubricant
-not aggressive to materials, sealants
With the emphasis on corrosion protection the nozzle fluid fulfills all the requirements.
