What Does IP68 Actually Mean

Water-Resistant Actuator IP68 True Submersion-Grade Performance
When it comes to deploying automation in the harshest environments — offshore platforms, marine vessels, wastewater treatment plants, or outdoor industrial sites — the term “water-resistant” is thrown around far too loosely. Many actuators claim protection against splashes or rain, but when submerged, they fail.

The only rating that truly separates a capable actuator from a fragile one is IP68.

An IP68-rated electric linear actuator isn’t just splash-proof or weather-sealed — it’s engineered for continuous immersion in water under real-world conditions. It represents the pinnacle of sealing technology and material science, designed not just to survive, but to perform reliably where failure could mean safety risks, environmental damage, or costly downtime.

Let’s go beyond marketing claims and explore what true IP68 performance means — down to the materials, design principles, and system integration considerations.

What Does IP68 Actually Mean?
The IP (Ingress Protection) code is defined by international standard IEC 60529, which classifies the degree of protection provided by electrical enclosures against solid objects and liquids.

An IP68 rating consists of two digits:

Digit Meaning
First digit: 6 Dust-tight – No ingress of dust; complete protection against contact
Second digit: 8 Protected against continuous immersion in water under conditions specified by the manufacturer
Unlike IP67 (which allows temporary immersion up to 1 meter for 30 minutes), IP68 has no time limit. The exact depth and duration are determined by the manufacturer through rigorous testing — often involving submersion at 5 meters for 48+ hours.

This distinction is critical: IP68 doesn’t assume dry periods. It assumes the actuator will be underwater — possibly for days — and still function when needed.

How Is IP68 Achieved? Engineering Beyond Seals
Achieving true IP68 compliance isn't about adding a single O-ring. It requires a holistic, multi-layered approach to sealing, materials selection, and internal component protection.
https://www.valen-tech.com/
1. Multi-Layer Sealing Architecture
A high-performance IP68 actuator uses several redundant barriers to prevent water ingress:

A. Double-Sealed Bearings
Standard actuators use a single bearing seal. In saltwater environments, this fails quickly. IP68 units employ dual-lip seals with:
https://www.tiemafaucet.com/
An outer wiper lip to remove debris and moisture.
An inner static seal to block capillary action. Both are made from Viton® (FKM) or EPDM rubber, resistant to UV, ozone, and seawater degradation.
B. Precision Lead Screw Seals
The lead screw is the most vulnerable point — it moves in and out, creating a potential path for water. IP68 actuators use:

Bellows boots or telescoping covers in extreme cases.
Multi-stage O-rings with labyrinth grooves to trap and deflect moisture.
Hydrophobic membranes that allow pressure equalization without letting water in.
These features ensure that even after thousands of cycles, the internal mechanism remains dry.

C. Molded Cable Glands with Strain Relief
Industrial actuators often use basic plastic glands that crack under UV exposure. IP68 models feature:

Overmolded PUR (polyurethane) cables with integral strain relief.
IP68-rated M12 or M23 connectors with double O-rings.
Capillary break design — preventing water from wicking along wire strands.
This stops moisture migration, one of the most common causes of silent electronic failure.

2. Potted Electronics: The Heart of Immersion Resistance
Even if external seals hold, condensation can form inside due to thermal cycling. Standard actuators with exposed PCBs fail silently.

True IP68 actuators use full epoxy potting:

The entire control board is encapsulated in thermally conductive, moisture-resistant resin.
This eliminates air gaps where condensation can form.
It also provides mechanical damping against vibration and shock.
The result? A solid block of electronics immune to humidity, salt spray, and short-term flooding.
https://hopomould.com/
? Example: On a boat hatch actuator, temperature swings between day and night can cause internal fogging. Without potting, this leads to corrosion and short circuits. With potting, it's irrelevant.

3. Corrosion-Resistant Materials: Fighting Galvanic Attack
Saltwater accelerates galvanic (electrolytic) corrosion, especially when dissimilar metals are in contact.

Industrial actuators may use aluminum housings or mild steel fasteners — fine indoors, but disastrous at sea.

IP68 marine-grade actuators use:

AISI 316L stainless steel housing and rod (contains molybdenum for chloride resistance)
Epoxy-coated lead screws to prevent internal rust
All-A4 (316) stainless steel fasteners
Sacrificial zinc anodes attached to the body to protect via cathodic protection
These aren’t optional upgrades — they’re essential for long-term survival in saline environments.

Where Are IP68 Actuators Used?
Because of their extreme durability, IP68-rated actuators are deployed wherever water exposure is guaranteed — not occasional.

Key Applications:
Industry Use Case
Marine & Boating Hatch covers, sunroofs, trim tabs, bilge dampers, sensor deployment
Wastewater Treatment Gate valves, sludge scrapers, digester controls
Food & Beverage Washdown conveyors, CIP (clean-in-place) systems, filler lines
Offshore Oil & Gas Subsea control pods, emergency shutdown valves, platform access systems
Renewables Tidal energy turbines, floating solar trackers, desalination plants
In all these cases, reliability isn’t just operational — it’s often tied to safety, regulatory compliance, and environmental protection.
https://www.topvictoryintl.com/
IP68 vs. Other Ratings: Know the Hierarchy
Don’t confuse IP68 with lower-tier protection levels. Here’s how they compare:

Rating Solid Object Protection Liquid Protection Real-World Suitability
IP65 Dust-tight Protected against low-pressure water jets Indoor use, light spray
IP66 Dust-tight Powerful water jets (e.g., heavy rain) Outdoor enclosures
IP67 Dust-tight Temporary immersion (≤1m, 30 min) Vehicle wash zones, temporary flooding
✅ IP68 Dust-tight Continuous immersion (>1m, indefinite) Marine, submersible, washdown
Only IP68 guarantees performance when full submersion is possible.

Why This Matters in Control System Design
Understanding IP68 is crucial not just for hardware selection — it impacts your entire control strategy.

Consider the legacy of pneumatic systems, as detailed in Valen Tech Co., Ltd.'s article:

Most pneumatic actuators operate on 60–100 psi power air, while 3–15 psi serves as the standardized pneumatic signal — a proportional command language.

Similarly, modern electric actuators must integrate into digital control loops:

4–20mA analog signals replace 3–15 psi commands.
Modbus RTU or CANopen enables bidirectional communication.
Position feedback confirms movement status.
But none of this matters if the actuator fails because water got inside.
https://www.ttifiber.com/
An IP68 actuator ensures:

Signal integrity over time
Reliable position reporting
Fault detection (e.g., jammed, overloaded)
Long-term compatibility with smart control networks
It transforms the actuator from a simple mover into a trusted node in an automated system.

Final Thoughts
A water-resistant actuator with an IP68 rating is not just a product specification — it’s a commitment to survivability.

It combines:

Full dust and water exclusion
Advanced sealing architecture
Corrosion-resistant construction
Potted electronics
Smart integration capabilities
…into a single rugged package built to perform when failure is not an option.

Whether you're automating a hatch on a yacht, controlling a valve in a treatment plant, or deploying equipment offshore, always ask:

Is this actuator rated IP68 — or just hoping to survive the rain?

Because in the real world, the difference shows up — eventually.

Looking for reliable, high-performance IP68-rated electric actuators?
Explore Valen Tech Co., Ltd.(www.valen-tech.com) — where innovation meets industrial strength. From precision motion control to robust system integration, Valen Tech delivers solutions engineered to perform in the toughest conditions, on land or offshore.