Sealing Standards for Harsh Environment Connectors: IP67, IP68, and Beyond

In demanding environments where dust, moisture, and contaminants pose constant threats to electrical performance, selecting the right sealed connector system is critical. For industries like defense, aerospace, industrial automation, and transportation, environmental sealing is not just a feature it's a functional requirement. Understanding the distinctions between IP67, IP68, and advanced sealing standards is essential for engineers selecting ruggedized interconnect solutions.

What Do IP67 and IP68 Mean?

The Ingress Protection (IP) rating system is defined by the IEC (International Electrotechnical Commission) under standard IEC 60529. IP ratings indicate how well a connector enclosure resists intrusion from solid objects and liquids.

An IP rating consists of two digits:

• The first digit (0–6): Protection against solids like dust.
• The second digit (0–9): Protection against water ingress.
  

The higher the numbers, the more rugged the protection but application requirements must guide the final choice.

When to Choose IP67 Connectors

IP67 rated connectors are the baseline for harsh-environment systems requiring full protection from dust and limited immersion.

Ideal for:

• Temporary outdoor installations
• Military communication equipment
• Field-deployable systems

They ensure systems remain operational even after exposure to rain, brief submersion, or dusty deployments. IP67 is often the minimum requirement in defense and aerospace electronics.

IP68: Higher Sealing for Continuous Exposure

IP68 rated connectors offer enhanced resistance to liquid ingress, including continuous immersion beyond 1 meter, as long as manufacturer-defined conditions are met.

Common applications:

• Underwater robotics
• Oil and gas exploration equipment
• Transportation systems exposed to flooding

Note that the exact depth and duration for immersion must be specified by the manufacturer, as IP68 is a broader category than IP67. One vendor's IP68 connector may be rated for 1.5 meters, another for 5 meters.

Going Beyond: IP69K and MIL-STD Sealing

While IP68 is sufficient for most submerged systems, some environments demand even more robust protection.

IP69K  connectors are designed for:

• High-pressure washdowns
• High-temperature steam cleaning
  

Industries like food processing, medical sterilization, and some aerospace operations benefit from IP69K-rated connectors.

For military systems, MIL-DTL-38999, MIL-DTL-26482, and similar specifications include environmental sealing as part of their design, often using O-ring compression, gasket seals, and back-shell sealing glands. These solutions ensure long-term survivability in sandstorms, salt fog, humidity, and altitude changes.

Sealed Connector Technologies: What Makes the Difference?

Environmental sealing is not just about external enclosures. Effective sealed connectors incorporate:

• Overmolding to provide strain relief and permanent environmental barriers
• O-rings and gaskets to prevent ingress at mating surfaces
• Sealing boots and grommets for cable exits
• Hermetic seals for gas-tight, moisture-impermeable needs
  

Advanced designs like Meritec’s rugged interconnects may include multi-stage seals or conformal potting to ensure total protection in extreme scenarios.

Comparison Table: IP67 vs IP68 vs IP69K

Choosing the Right Sealed Connector: Key Considerations

Selecting a sealing standard requires understanding both environmental risks and long-term reliability needs:

• Operating conditions: Dust levels, rain, submersion, or washdown?
• Exposure duration: Short-term splash vs. permanent submersion?
• Mechanical stress: Will the connector undergo movement or vibration?
• Chemical contact: Industrial fluids or corrosive agents present?
  

Designing for IP68+ also means addressing cable ingress, as many failures occur at the cable interface. Using overmolded or strain-relieved designs reduces this risk significantly.

Meritec’s Solutions for Harsh Environments

Meritec provides a wide range of sealed connector and cable assembly solutions designed for harsh applications across defense, aerospace, transportation, and medical sectors. Our capabilities include:

• IP67 and IP68 cable assemblies with overmolded terminations
• Custom sealing for MIL-DTL-38999 and micro circular connectors
• Hybrid interconnects combining power, signal, RF, and fiber with environmental protection
• Testing for thermal shock, submersion, salt fog, and vibration

Whether you need a fully submersible sensor connection or a field-deployable rugged interface, Meritec designs solutions to meet stringent sealing and mechanical requirements.

Final Thoughts: Don’t Underestimate Environmental Sealing