Product Spotlight: Martec MSC Subsea Connectors : Hermetic Sealing for Deep-Water Reliability
In subsea equipment, the connector is part of the pressure boundary. It must maintain electrical performance while exposed to water, pressure, corrosion, vibration, and temperature changes.
The Martec MSC subsea connector series is designed for this environment. The series combines hermetic glass-sealed plugs and receptacles with rugged metal construction and familiar military connector interfaces.
For design-in engineers, the result is a connector platform that supports reliable electrical transitions in underwater, offshore, oceanographic, defense, and other extreme-environment systems.
CTM Marketing represents Martec as a local technical resource for manufacturers and engineering teams in the Rocky Mountain Region. Contact CTM for application guidance, product selection, and design-in support.
Key MSC Connector Features
The Martec MSC series is designed around several common subsea design requirements:
Hermetic glass-sealed plugs and receptacles
Pressure capability up to 1500 PSI in mated conditions
MIL-DTL-38999 planforms and keyways
Stainless steel shells
Marine bronze coupling nuts
Integral backshells for EMI performance
Operating temperature range from -55°C to +200°C
Jam nut or square flange mounting styles
UNEF thread coupling
The specific part number, contact arrangement, termination, and mounting configuration should be confirmed against the applicable Martec datasheet.
Hermetic Glass Sealing for Subsea Protection
A subsea connector must do more than resist surface water. It must help prevent moisture and pressure from reaching sensitive electrical interfaces.
The MSC series uses hermetic glass sealing in the plug and receptacle design. Glass-to-metal sealing creates a robust barrier around the contacts. This supports electrical isolation and protects the internal connection path from the surrounding environment.
This approach is useful when the connector is part of:
A pressure housing
A subsea instrument
A downhole measurement system
An oceanographic sensor platform
An offshore energy assembly
A defense or surveillance system
Hermetic sealing also helps address corrosion concerns. By limiting environmental access to the contact interface, the connector design can reduce one of the common causes of long-term subsea electrical failure.
The sealing strategy must still be evaluated as part of the complete assembly. Cable construction, overmolding, backshell integration, enclosure design, and installation practices all affect final system performance.
1500 PSI Capability in Mated Conditions
The MSC series is designed for pressure capability up to 1500 PSI when mated.
That rating can simplify early connector screening. Instead of treating the connector as a standard component inside a larger system, engineers can evaluate it as part of the equipment’s complete pressure and environmental architecture.
During the design-in phase, confirm:
The required pressure level and duration.
Whether the pressure is applied externally, internally, or differentially.
Whether the connector remains mated during exposure.
The expected number of mate and demate cycles.
The effects of temperature, vibration, and fluid exposure.
The exact Martec part number and test conditions.
Do not use a general series rating as a substitute for a part-specific qualification review. CTM can help connect your engineering team with Martec to confirm the correct datasheet and application details.
Familiar MIL-DTL-38999 Planforms and Keyways
A major design-in benefit of the MSC series is its use of MIL-DTL-38999 planforms and keyways.
Design teams often prefer established interfaces. Familiar planforms can support easier integration with existing panel layouts, mounting practices, tooling, and qualification processes. Keying options also help control connector orientation and reduce the risk of mismating.
For new equipment, a familiar interface can reduce mechanical design effort. For upgrades, it may provide a path to improve environmental performance without redesigning the entire connection architecture.
The MSC series also uses UNEF thread coupling. Threaded coupling provides a defined mechanical engagement method for applications where secure retention is important.
When evaluating the interface, review:
Available shell size and contact layouts
Keyway requirements
Coupling thread details
Panel cutout and mounting clearances
Mating access in the equipment
Torque and installation requirements
Backshell and cable routing space
Verify compatibility before releasing mechanical drawings. The planform may be familiar, but the final mounting and backshell arrangement must match the selected configuration.
Materials for Corrosion-Exposed Environments
Material selection is a central consideration for subsea connector reliability.
The MSC series uses stainless steel shells and marine bronze coupling nuts. These materials are intended for demanding marine and underwater environments where corrosion resistance and mechanical strength are important.
The shell provides the primary connector body and mounting structure. The coupling nut supports the mated connection and must withstand repeated handling, environmental exposure, and mechanical loading.
Material compatibility should be reviewed across the entire assembly. Pay attention to:
Connector shell and mounting hardware
Coupling nut and mating interface
Panel material
Fasteners
Cable armor or braid
Protective coatings
Contact materials
Exposure to seawater or process fluids
Galvanic compatibility can depend on the materials surrounding the connector. CTM and Martec can help review the intended installation and identify questions for the final qualification plan.
Integral Backshells Support EMI Performance
Subsea systems frequently combine sensors, power electronics, digital communications, and control circuits in a compact package. Electromagnetic interference can affect signal integrity and system operation.
The MSC series includes integral backshells designed to support EMI performance. Integrating the backshell with the connector helps create a more controlled transition between the connector shell, cable shield, and equipment enclosure.
This can provide a cleaner approach than adding a separate backshell as an afterthought.
During layout and cable design, review:
Shield termination method
Cable braid or foil construction
Grounding and bonding strategy
Backshell clearance
Bend radius near the connector
Separation between power and signal wiring
Continuity across the mated interface
EMI performance is system-dependent. The connector is one part of the shielding and grounding strategy. Final performance should be verified in the completed equipment.
Wide Temperature Range for Thermal Cycling
The specified operating temperature range for the MSC series is -55°C to +200°C.
This wide range supports applications that may move between cold storage, ambient operation, internal equipment heating, and elevated-temperature exposure. It is also relevant for systems that experience repeated thermal cycling during deployment, operation, maintenance, or transportation.
Thermal cycling can place stress on:
Sealing interfaces
Glass-to-metal transitions
Cable jackets
Overmolded sections
Contact terminations
Mounting hardware
Adjacent enclosure materials
A connector selected for a wide temperature range still needs to be evaluated with the complete cable and enclosure assembly. The lowest-rated component may define the system limit.
Mounting Options for Equipment Integration
The MSC series is available in jam nut and square flange mounting styles.
These options allow engineers to match the connector to the enclosure and assembly process.
A jam nut style may support compact panel integration where rear-side access and a threaded mounting arrangement are available. A square flange style may be useful when the design calls for a bolted mounting pattern or a defined flange interface.
Before selecting a style, confirm:
Panel thickness
Front-side and rear-side access
Mounting hole pattern
Sealing method at the panel
Available wrench clearance
Connector orientation
Cable and backshell routing
Assembly and service requirements
Choosing the mounting style early can prevent enclosure changes later in the development cycle.
Design-In Guidance for MSC Connectors
Use the following process when evaluating the Martec MSC series:
1. Define the environment
Document pressure, temperature, fluid exposure, vibration, shock, and expected service life.
2. Define the electrical interface
Identify contact count, signal type, voltage, current, shielding, and cable construction.
3. Confirm the mechanical interface
Select the planform, keyway, coupling style, shell size, and mounting configuration.
4. Review the complete assembly
Evaluate the connector, cable, backshell, enclosure, mounting hardware, and sealing interfaces as one system.
5. Confirm qualification requirements
Request the applicable Martec datasheet, drawings, test information, and any required customer-specific qualification data.
Martec provides additional information on high-pressure and high-temperature hermetic solutions and MIL-Spec hermetic connectors. Use those resources as a starting point, then confirm the exact configuration for your application.
Work with CTM During the Design-In Phase
The connector decision is often made early. Once the enclosure, cable, and interface are released, changing the connector can create schedule and qualification problems.
CTM Marketing helps engineering teams evaluate connector requirements before those decisions become difficult to change. As a technical sales agency and local component sales representative, we connect design engineers with Martec’s product and application resources.
CTM supports customers across Arizona, Colorado, Idaho, Montana, New Mexico, Utah, and Wyoming. Our design-driven approach focuses on matching application needs with engineered products from our principals.
Learn more about CTM’s approach to design-in support and the role of manufacturers representatives in the design-in phase.
Let’s Chat!
Are you designing subsea, offshore, oceanographic, defense, or extreme-environment equipment?
Send CTM your connector requirements. We can help review the pressure, temperature, mounting, EMI, and interface needs, then coordinate with Martec on the appropriate MSC configuration and full datasheet information.
Contact CTM Marketing for design support in the Rocky Mountain Region.
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