When automating industrial pipelines, the mechanical strength of your valve is irrelevant if the electric actuator driving it shorts out due to water ingress. For procurement managers and automation engineers specifying motorized valves, deciding between an IP67 and IP68 enclosure is a critical risk-management decision. If you need an immediate engineering directive on actuator protection ratings, here is our bottom-line recommendation:
- For general outdoor use, rain exposure, and washdown areas: Specify an IP67 actuator. It is completely dust-tight and can survive temporary immersion in shallow water. It is the most cost-effective standard for 90% of above-ground plant operations.
- For underground vaults, flood-prone pits, and submerged municipal lines: You must mandate an IP68 actuator. IP68 units are double-sealed and potted, designed to operate continuously underwater without allowing a single drop of moisture into the electrical terminal block.
- The Hidden Condensation Threat: Never assume a high IP rating prevents internal moisture. You must specify an internal anti-condensation space heater for both IP67 and IP68 actuators to prevent circuit board corrosion caused by temperature fluctuations.
A burnt-out electric actuator on a critical cooling water or chemical line can trigger millions in downtime. In this comprehensive manufacturer’s guide, we will decode the Ingress Protection (IP) rating system, examine the structural differences between IP67 and IP68 enclosures, and share field-tested insights to ensure your automated vannes papillon industrielles and ball valves survive the harshest environments.
1. Demystifying the IP Rating System
The IP (Ingress Protection) rating system is an internationally recognized standard (IEC 60529) that classifies the degree of protection an electrical enclosure provides against solid objects (dust, dirt) and liquids (water). For a broad overview of actuator accessories, you can review our guide on selecting the proper IP rating for valve actuator accessories.
The rating consists of two digits. The first digit represents protection against solid particles, and the second digit represents protection against water.
- First Digit “6”: Dust-tight. No ingress of dust; complete protection against contact. Both IP67 and IP68 actuators offer this maximum level of dust protection.
- Second Digit “7” (Temporary Immersion): Protected against the effects of temporary immersion in water (up to 1 meter deep for exactly 30 minutes).
- Second Digit “8” (Continuous Immersion): Protected against continuous submersion in water under conditions specified by the manufacturer (e.g., 10 meters deep for 72 hours, or even permanent submersion).
2. IP67 Electric Actuators: The Above-Ground Standard
In the vast majority of industrial applications—from oil refineries to standard HVAC chiller plants—valves and actuators are installed above ground. They are exposed to heavy rain, snow, blowing sand, and high-pressure hose washdowns during plant cleaning.
Engineering Profile
An IP67 electric actuator utilizes heavy-duty O-rings and gasket seals between all aluminum housing joints, specifically at the top cover and the terminal box cover. The cable entries are equipped with standard waterproof cable glands. If a torrential downpour hits the plant, or if a nearby pipe bursts and briefly sprays the actuator, the internal motor and circuit boards remain completely dry.
Where IP67 Fails
The limitation of IP67 is sustained hydrostatic pressure. If an IP67 actuator is installed in a drainage pit, and heavy rains cause that pit to fill with 3 feet of water for two days, the prolonged pressure will eventually force water past the standard O-rings. The electrical components will short out, and the actuator will be destroyed. For environments where pooling water is a guarantee, IP67 is a dangerous under-specification.
3. IP68 Electric Actuators: The Ultimate Flood Protection
When you move into traitement des eaux environnementales, desalination plants, or municipal underground piping, valves are frequently installed in concrete subterranean vaults. These vaults are notorious for flooding during storms or due to minor pipeline leaks. To ensure the valve can still operate (e.g., to isolate a broken pipe) while entirely underwater, IP68 is an absolute necessity.
The “Double-Sealed” Architecture
Achieving a true IP68 rating requires significantly more than just thicker O-rings. Premium IP68 electric actuators feature a “Double-Sealed” terminal compartment. In a standard actuator, opening the cover to wire the power cables exposes the inner motor and motherboard. If it rains during wiring, the unit is compromised.
In a double-sealed IP68 unit, the terminal block (where the external wires connect) is physically sealed off from the main internal components containing the motor and logic board. Even if water leaks through a poorly installed external cable gland into the terminal block, it cannot cross the internal barrier to reach the brain of the actuator. Furthermore, high-end IP68 actuators utilize resin-potted electrical connections to ensure absolute water resistance under high hydrostatic pressure.
4. Valve Actuation Challenges: Butterfly vs. Ball Valves
The type of valve you are automating directly influences your actuator selection and budget. When an electric actuator fails due to water ingress, replacing it is expensive—but the cost depends heavily on whether it was turning a ball or butterfly valve.
Automating an industrial ball valve requires immense torque because the large steel ball generates severe friction against its seats. Consequently, electric actuators for large ball valves are physically massive and highly expensive. If an improperly specified IP67 actuator on a 12-inch ball valve floods, the replacement cost is staggering.
Conversely, butterfly valves require much lower operating torque. The actuator is smaller and cheaper. However, because butterfly valves are frequently installed in tight, low-lying spaces or underground water mains, they are statistically much more likely to experience flooding. In these scenarios, paying a small premium upfront to upgrade from IP67 to IP68 for your butterfly valve automation package is the smartest insurance policy a plant manager can buy.
5. Manufacturer Insights: The Condensation Trap
At JH Valve, we have spent 60 years diagnosing failed automated valves. One of the most frustrating experiences for a procurement manager is buying an expensive, fully certified IP68 electric actuator, only to have it short out with a rusted motherboard six months later, despite never being submerged.
How does water get into a perfectly sealed IP68 enclosure? The answer is condensation.
Industrial environments experience day-to-night temperature swings. As the actuator motor runs, it generates heat. When it turns off and the ambient temperature drops (such as at night), the air trapped inside the sealed aluminum enclosure cools rapidly. The moisture naturally present in that trapped air condenses into liquid water droplets directly onto the circuit boards and limit switches.
Because the IP68 enclosure is perfectly sealed, that water cannot escape. It builds up over time, eventually causing a fatal short circuit. To prevent this, you must specify an internal anti-condensation space heater for every electric actuator. This tiny, low-wattage resistor continuously runs inside the housing, keeping the internal temperature just a few degrees above the ambient dew point, ensuring condensation never forms.
6. Electric vs. Pneumatic Actuators in Wet Environments
If your facility experiences constant, heavy flooding, you might consider abandoning electric actuators entirely. We often recommend switching to actionneurs pneumatiques for severe, continuously submerged environments.
Because pneumatic actuators rely purely on compressed air driving mechanical pistons, they have no sensitive circuit boards or electric motors to short out. Even if a pneumatic actuator is completely submerged, as long as the air supply lines are intact and the exhaust ports are piped above the water line, it will function flawlessly underwater. However, pneumatic systems require the infrastructure of a massive plant air compressor, which is not feasible for remote or isolated pipeline locations where electric power is the only option.
Comprehensive IP67 vs IP68 Comparison Matrix
To assist your engineering and procurement teams, here is a definitive side-by-side performance matrix for electric valve actuators:
| Protection Metric | IP67 Electric Actuator | IP68 Electric Actuator |
|---|---|---|
| Dust Protection | 100% Dust-Tight (Level 6) | 100% Dust-Tight (Level 6) |
| Water Protection Limits | Immersion up to 1 meter for 30 minutes | Continuous submersion (e.g., 10m for 72 hrs+) |
| Internal Architecture | Standard single-compartment seals | Double-sealed terminal compartments |
| Cable Entry Vulnerability | High risk if glands are installed poorly | Low risk (Terminal box isolated from main motor) |
| Capital Cost | Coût de base standard | Premium (Usually 15% – 30% higher) |
| Ideal Installation Environment | Above ground, process skids, outdoor racks | Underground vaults, flood pits, marine decks |
| Space Heater Required? | Yes (To prevent condensation) | Yes (To prevent condensation) |
Foire aux questions (FAQ)
1. What is the NEMA equivalent for IP67 and IP68?
In North America, NEMA ratings are commonly used instead of IP ratings. An IP67 rating is roughly equivalent to a NEMA 4X or NEMA 6 enclosure (watertight, dust-tight, and corrosion-resistant). An IP68 rating aligns closely with a NEMA 6P enclosure, which is explicitly rated for prolonged submersion.
2. If my IP68 actuator is fully waterproof, why did it still fail underwater?
The most common cause of IP68 failure underwater is improper cable gland installation. If the electrician uses cheap, non-IP68 rated cable glands, or fails to properly tighten them around the incoming power cables, hydrostatic pressure will force water straight down the wire jacket directly into the terminal block.
3. Can an IP67 actuator handle high-pressure washing?
Yes, but with limits. IP67 can handle heavy rain and standard hose washdowns. However, if your plant uses aggressive, high-pressure, high-temperature steam jets (like in food and beverage facilities), you actually need an IP69K rated enclosure, which is specifically designed to resist high-pressure, high-temperature washdowns.
4. Does “double-sealed” mean the actuator has two covers?
No, it means the internal terminal block is physically isolated from the main control compartment. You can remove the outer cover to wire the power cables without ever exposing the sensitive internal circuit boards to the outside atmosphere, severely reducing the risk of accidental moisture ingress during commissioning.
5. Do I need an IP68 actuator if my pipeline is buried?
Yes, absolutely. Any valve buried in the soil or located in an underground municipal vault is virtually guaranteed to experience flooding from heavy rainfall, rising water tables, or pipe leaks. Specifying IP67 for a buried application is a major engineering risk.
6. Will the internal space heater burn out the actuator in hot weather?
No. Industrial anti-condensation heaters are very low wattage (typically 5 to 10 watts) and are often paired with a thermal switch or PTC resistor. They self-regulate and merely keep the internal ambient temperature slightly higher than the exterior housing, utilizing negligible electricity while providing critical protection.
7. Is it possible to upgrade an IP67 actuator to IP68 later?
Generally, no. The difference between IP67 and IP68 is not just thicker O-rings; it involves the fundamental casting of the aluminum housing to allow for double-sealed compartments and potted electronics. You must specify the correct IP rating at the time of purchase.
Conclusion
Protecting the “brain” of your automated valve is just as important as the valve’s mechanical integrity. For the vast majority of exposed, above-ground industrial piping, the IP67 electric actuator provides robust, cost-effective defense against harsh weather. However, the moment your valve enters a pit, an underground vault, or a flood-prone zone, the double-sealed, continuously submersible protection of an IP68 electric actuator becomes an absolute necessity to prevent catastrophic failure.
Are you automating a challenging pipeline or battling burnt-out actuators?
Do not guess on your ingress protection. Leverage JH Valve’s 60 years of API, CE, and SIL3 certified manufacturing excellence. 📧 Contact our automation engineering team today at JH-valve@janhenvalve.com for expert actuator sizing, customized double-sealed IP68 packages, and bulletproof automation solutions!
