Spray Nozzle Engineering and nozzle manufacturer BETE advise that it is important to match the right nozzle material to any specific application.
Improved reliability, proper performance and maximum wear life of a spray nozzle often begin with the correct material selection. Corrosion and erosion caused by abrasive wear are the most common factors that could lead to degradation of a nozzle’s performance.
It is important to select the right nozzle material depending on the environmental conditions of the given process. Spray Nozzle Engineering and BETE help customers choose the best nozzle material for any application.
Nozzle material selection is influenced by a variety of factors such as temperature, corrosion, erosion, weight and initial vs. total costs.
Melting or softening of nozzle material establishes maximum temperature limits. However, these limits must be reduced when corrosion, oxidation or chemical attack are also present in the given application.
Nozzle material performance and reliability varies with exposure to different chemical types and concentrations. It is important to consider the properties of the environment where the nozzle is installed and the properties of the fluid spraying through the nozzle.
Corrosion is material related and caused by chemical attack. Nozzles can be made in a wide range of materials and proper selection of the nozzle material will minimise corrosion problems.
For instance, plastics offer superior corrosion resistance at relatively low cost, but can only be used in low-temperature applications. Ceramics on the other hand have excellent corrosion resistance except in very high pH environments.
Metals can be ranked in the following order of corrosion resistance (from lowest to highest): Carbon steel, brass, stainless steel, nickel-based alloys, refractory metals and precious metals.
Erosion (or abrasion wear) is also material based and can cause the nozzle to wear out prematurely, leading to increased flow and degraded spray formation, resulting in increased process fluid costs and unacceptable process quality.
Hardened stainless steel, Cobalt Alloy 6, tungsten carbide and ceramics are commonly used materials in applications where abrasive fluids are sprayed.
Nozzles made from a strong, yet lightweight material such as titanium can be the perfect solution for applications that require low structural weight.
Initial vs. Total Cost
In terms of cost, materials can generally be ranked in the following order (from lowest to highest): Brass, carbon steel, plastics, stainless steel, cobalt-based alloys, nickel-based alloys, ceramics, refractory metals and precious metals.
But, it is also extremely important to consider the long-term costs of having a nozzle in a material not suited for the application, impacting operating costs due to frequent shutdowns for nozzle replacement as well as product or process quality.
BETE and Spray Nozzle Engineering can supply the nozzle in the selected material. BETE uses three basic manufacturing processes for their nozzles based on the material. Multi-component fabricated assemblies in complex designs with multiple types of materials can also be supplied.
BETE’s nozzle manufacturing processes:
- Injection moulding is used for large quantities of nozzles made from plastics such as PVC, ABS and PVDF
- CNC machining is used for metal alloy nozzles and plastic nozzles that have relatively small quantities
- Investment casting offers the flexibility to produce complex shapes in common or speciality alloys that provide a unique performance advantage