Industrial facilities in harsh environments, such as salt sprays and chemical exposures, often encounter various challenges related to corrosion. This may cause the equipment to deteriorate rapidly unless the right protective measures are taken. When it comes to automated valve actuators, it is very important to choose a good corrosion resistant actuator in order to minimize maintenance costs in the long term.
Electric valve actuators in water treatment, desalination, and chemical processing facilities, as well as in marine environments, need to be able to withstand harsh environments. This is achievable by selecting the right material and coating standards.
Identifying the Enemies: Salt Spray, Acids, and Chemical Vapors
Corrosion happens when environmental impurities react with exposed metal surfaces. There are various corrosion sources in most industrial environments that may affect actuator housings, fasteners, and internal components.
| Corrosion Source | Typical Industrial Environment | Impact on Actuators |
| Salt spray | Offshore platforms, coastal plants, and desalination facilities | Accelerates metal oxidation and structural degradation |
| Acidic vapors | Chemical processing plants | Causes chemical corrosion and material breakdown |
| High humidity | Wastewater treatment plants | Promotes rust and internal electrical damage |
| Chemical exposure | Industrial manufacturing facilities | Weakens coatings and protective surfaces |
Therefore, in such conditions, actuators must be designed with corrosion-resistant materials and designs in order to be reliable in the long term.
Material Comparison: Aluminum Alloy vs. Ductile Iron Housings
The type of material used for the actuators’ housings has a major impact on corrosion resistance and durability. For industrial electric actuators for use in industrial valves, the materials used are engineered metals with special coatings and the use of stainless steel for the screws and fasteners.
| Housing Material | Corrosion Resistance | Typical Applications | Advantages |
| Die-cast aluminum housing | Good | General industrial plants, water treatment | Lightweight, cost-effective, and corrosion resistant when coated |
| Hard aluminum alloy housing | Very good | Chemical processing and marine environments | Improved strength and enhanced durability |
| Ductile iron housing | High structural durability | Heavy-duty industrial systems | Excellent mechanical strength and stability |
Die-cast aluminum or ductile iron materials are common for industrial electric actuators’ housings. These materials are then given special coatings. Apart from the materials used for the actuators’ housings, the use of screws and fasteners made of stainless steel is common for industrial electric actuators.
For installations where more severe environmental conditions exist, such as those found at offshore platforms or chemical plants, actuators may also provide optional protection for highly corrosive environments, thus adding to the inherent protective features provided to the housing.
Proper selection of the material used in the housing is critical to ensure that environmental stress is not placed on the actuator while maintaining valve automation performance.
High-Performance Coatings: Epoxy, PTFE, and Nickel Plating Explained
The surface coating forms an important interface between the corrosive environment and the housing of the actuators. Electric actuators in industries use Polyester powder coating as per the GBT 18593-2001 standard. This coating is effective in providing protection for the metal surfaces against moisture, chemicals, and salt.
| Coating System | Protection Benefit | Typical Applications |
| Polyester powder coating (GBT 18593-2001) | Durable barrier against moisture, chemicals, and salt spray | Wastewater treatment, chemical plants, and marine environments |
| High-corrosion protection upgrade | Enhanced protection for aggressive industrial environments | Offshore facilities, chemical processing plants |
In addition to the coating, stainless steel screws and external fasteners are also used to prevent rust and ensure the durability of the actuators in a corrosive environment.
For applications that are exposed to severe corrosion conditions, specific upgrade options may be available for highly corrosive conditions.
Protecting the Internals: IP68 Sealing and Internal Heater Benefits (Preventing Condensation)
External protection is not the only option. Internal components of the motor, gears, and electronic controls must also be protected from moisture penetration.
An IP68 rated actuator provides good protection against the elements. The actuator is dust-tight and may be operated in water or flooded environments. This is a good feature for outdoor and coastal applications.
Internal heaters play an important role in the protection of the actuator. Changes in temperature may cause condensation inside the actuator. This may lead to corrosion of the electrical components. The internal heaters will help to maintain a consistent internal temperature.
Selecting Based on Specific Plant Media (Wastewater, Desalination, or Offshore)
Each industrial setting poses a unique corrosive condition on the actuators used in the plant. Actuators are chosen based on the plant media, which helps ensure proper operation as well as a longer lifespan.
| Plant Environment | Primary Corrosion Risk | Recommended Actuator Solution |
| Wastewater treatment plants | High humidity and chemical exposure | Epoxy coated actuators with sealed enclosures |
| Desalination plants | Continuous saltwater exposure | Stainless steel electric actuator with strong sealing protection |
| Offshore platforms | Salt spray and extreme weather | Marine grade valve actuator with advanced corrosion resistance |
For marine and offshore applications, a marine grade valve actuator is generally called for. The actuators are constructed with corrosion-resistant materials, durable coatings, and sealed enclosures suitable for saltwater conditions.
The “AOX-R” series features a compact structure with excellent weather resistance and vibration resistance.
LEARN MOREConclusion: Reducing TCO with Superior Corrosion Protection
It is important to note that corrosion is a key factor in the proper functioning and lifespan of an industrial valve automation system. A corrosion resistant actuator requires proper evaluation.
It is possible for industries to minimize failures through the use of corrosion-resistant materials and coatings. This also helps in reducing costs in the long term.
Investing in corrosion-resistant actuators for industrial plants is a key step in ensuring the proper functioning of the system. This is especially important for industries operating in harsh conditions.
