The BH25F is a 25-contact SubConn® Circular Female Bulkhead subsea connector serving as a panel-mount bulkhead feedthrough that mounts through instrument housing walls, chassis panels, or pressure vessel bulkheads. Rated to 600 V DC/AC / 10 A (power) / 5 A (signal) with a qualified hydrostatic pressure of 1,400 Bar (20,300 psi) when mated, the Circular series delivers industry-leading electrical capacity and depth performance for ROV systems, oceanographic instrumentation, naval applications, and offshore energy installations. Gold-plated brass contacts and chloroprene rubber construction guarantee 500+ wet mating cycles with insulation resistance exceeding 200 MΩ across the rated service life.
25 Contacts | 600 V DC/AC | 10 A (power) / 5 A (signal) | Max 60 A | 1,400 Bar Mated | 500+ Wet Matings | SubConn® Standard
Key Design Features
- SubConn® Circular Standard series — the original high-voltage subsea circular connector platform, rated at 600 V DC/AC rms (2× the Micro Circular voltage rating)
- 25-contact Female Bulkhead — panel/bulkhead feedthrough; optimised for high-current subsea power and multi-circuit signal distribution
- 1,400 Bar mated pressure — qualified to 1,400 Bar / 20,300 psi hydrostatic (14,000 m (exceeds any ocean depth))
- 800 Bar open-face pressure — unmated connector face withstands 800 Bar / 11,600 psi without flooding
- 500+ wet mating cycles — qualified for repeated in-situ mate/demate in full-salinity seawater
- Gold-plated brass contacts — Female sockets in gold-plated brass UNS-C36000; contact resistance < 10 mΩ, corrosion-immune in ocean salinity across 500+ cycles
- Chloroprene rubber body — resists seawater, hydraulic oil, and biofouling; −4 °C to +60 °C operational range
- Multi-material bulkhead body — brass, 316L stainless steel, titanium, anodised aluminium, or PEEK — material-matched to any hull or chassis
- PEEK depth variant — certified to 300 Bar / 4,350 psi for 3,000 m deployments requiring electrical isolation
- Mixed power/signal layout — 3 power contacts rated 10 A per contact plus 22 signal contacts rated 5 A per contact; max 60 A connector current capacity
Electrical & Mechanical Specifications
| Parameter | Specification |
|---|---|
| Number of Contacts | 25 |
| Rated Voltage | 600 V DC/AC rms |
| Rated Current (per contact) | 10 A (power) / 5 A (signal) |
| Maximum Current (connector) | 60 A |
| Insulation Resistance | > 200 MΩ |
| Contact Resistance | < 10 mΩ per contact (< 0.01 Ω) |
| Qualified Pressure — Mated | 1,400 Bar / 20,300 psi |
| Qualified Pressure — Open Face | 800 Bar / 11,600 psi |
| PEEK Variant Depth Rating | 300 Bar / 4,350 psi (~3,000 m) |
| Wet Mating Cycles | > 500 cycles in seawater |
| Operating Temperature (water) | −4 °C to +60 °C |
| Operating Temperature (air) | −40 °C to +60 °C |
| Storage Temperature | −40 °C to +60 °C |
| Contact Material | Female sockets in gold-plated brass UNS-C36000 |
| Connector Body | Chloroprene rubber |
| Bulkhead Body Options | Brass, 316L stainless steel, titanium, anodised aluminium, PEEK |
| O-Ring Material | Nitrile |
| Snap Rings | Stainless steel AISI 302 |
| Locking Sleeves | POM or stainless steel |
| Inline Cable | 3 × 18 AWG, 0.82 mm² + 22 × 20 AWG, 0.52 mm² polyurethane |
| Connector Style | Circular Female — Bulkhead |
Typical Applications
- ROV / AUV power systems — high-current 25-circuit connections for thruster power, hydraulic pump drives, and manipulator arm motor drivers rated up to 60 A
- Subsea instrument arrays — 600 V / 10 A (power) / 5 A (signal) connections for deep-sea sensor nodes, CTD systems, ADCPs, and multi-parameter oceanographic instruments
- Underwater cameras and lighting — high-power 25-circuit connections for 4K camera systems and high-lumen LED lighting arrays
- Cabled ocean observatories — inter-node power distribution connections in long-term seabed observatory networks (OOI, NEPTUNE, EMSO)
- Offshore energy systems — subsea monitoring, control, and umbilical termination connectors in marine renewable energy installations
- Naval and defence systems — sonar array power and signal harnesses in submarines and unmanned underwater vehicles (UUVs)
- Subsea mooring systems — cable terminations in profiling mooring systems and autonomous underwater profilers
- Saturation diving systems — life support and communication cable connections rated for full operational saturation diving depths
- Subsea production systems — monitoring and control connections in subsea trees, manifolds, and pipeline integrity monitoring systems
Why Choose the BH25F
1. 600 V Rating — Double the Voltage of Micro Circular
The SubConn® Circular standard series is rated at 600 V DC/AC rms — twice the 300 V rating of the Micro Circular series. This higher voltage capability makes the BH25F the correct choice for subsea motor drivers, thruster power supplies, high-power LED lighting, and any application where power delivery efficiency requires higher voltage to reduce cable losses and connector current at a given power level.
2. 1,400 Bar Qualified — 14,000 m (exceeds any ocean depth)
Qualified to 1,400 Bar (20,300 psi) when mated. At typical ROV operating depths of 300–6,000 m, this rating provides a pressure safety factor of 2.3× to 46×. The open-face (unmated) rating of 800 Bar / 11,600 psi means the connector can be pressurised prior to mating without flooding — critical for wet-mate operations in deep ROV tooling deployments.
3. 500+ Wet Mating Cycles — Full Service Life Qualification
Qualified for more than 500 wet mate/demate cycles in full-salinity seawater. Gold-plated brass contacts maintain contact resistance below 10 mΩ across all cycles, avoiding the resistance drift seen with tin or nickel contacts after 20–50 seawater cycles. This qualification supports ROV tooling skid operations, seasonal observatory maintenance, and high-frequency instrument deployment programmes.
4. True SubConn® Circular Standard — OEM-Grade Supply
RV POWER GROUP manufactures the BH25F to the SubConn® Circular standard geometry, with all mating dimensions, keyway orientation, and locking sleeve geometry conforming to the industry-standard Circular series. This enables direct integration with existing SubConn® harnesses and systems at competitive pricing, with OEM-grade quality control and pressure test certification available on request.
5. Multi-Material Body — Application-Matched Configuration
Bulkhead body options — brass, 316L stainless steel, titanium, anodised aluminium, and PEEK — allow system designers to match connector material to instrument housing material, eliminating galvanic corrosion risk. Titanium is specified for CFRP AUV hulls and long-term observatory deployments; PEEK provides full electrical isolation and chemical resistance for electrochemical sensing and cathodic protection applications.
SubConn® Circular Series — Complete 25-Contact Family
| Part Number | Type | Gender | Mount | Description |
|---|---|---|---|---|
| BH25M | Bulkhead | Male | Panel | Panel-mount bulkhead male, housing feedthrough |
| BH25F | Bulkhead | Female | Panel | Panel-mount bulkhead female, housing feedthrough |
| IL25M | In-Line | Male | Cable | Cable-mount in-line male, mid-run connection |
| IL25F | In-Line | Female | Cable | Cable-mount in-line female, mid-run connection |
| DC25M | Dummy Cap | Male | — | Protective dummy plug for unmated male face |
| DC25F | Dummy Cap | Female | — | Protective dummy plug for unmated female face |
| BH25F | Bulkhead | Female | Panel | This product |
How to Select the Right BH25F Configuration
| Application Requirement | Recommended Variant | Reason |
|---|---|---|
| Standard ROV / AUV, < 3,000 m, power distribution | BH25F (Brass body) | Cost-optimised; 1,400 Bar provides 4.7× factor at 3,000 m |
| Long-term seabed deployment (> 12 months) | BH25F (Titanium or SS body) | Superior corrosion and biofouling resistance |
| CFRP / carbon-fibre AUV hull interface | BH25F (PEEK body) | Electrical isolation prevents galvanic corrosion at CFRP interface |
| Shallow-water ROV (< 3,000 m), weight-critical | BH25F (Anodised Al body) | Lowest-mass metal body option |
| High-current power application (max load) | BH25F standard | 600 V / 10 A (power) / 5 A (signal) — 60 A max; SubConn® Circular rated for continuous high-current operation |
Frequently Asked Questions — BH25F Subsea Connector
Q: What is the maximum depth rating for the BH25F?
A: Qualified to 1,400 Bar (20,300 psi) when mated — approximately 14,000 m (exceeds any ocean depth). Open-face (unmated) pressure rating is 800 Bar / 11,600 psi. A PEEK body variant provides certified depth rating of 300 Bar / 4,350 psi (~3,000 m).
Q: What voltage is the BH25F rated for?
A: The SubConn® Circular standard series is rated at 600 V DC/AC rms — twice the voltage rating of the Micro Circular series (300 V). This makes the Circular series the correct choice for subsea motor drives, high-power thrusters, and applications requiring maximum power delivery efficiency.
Q: What is the current rating of the BH25F?
A: 10 A (power) / 5 A (signal) per contact, with a maximum connector current of 60 A. Gold-plated brass contacts maintain contact resistance below 10 mΩ across 500+ wet mating cycles.
Q: How many wet mating cycles can the BH25F withstand?
A: Qualified for more than 500 wet mate/demate cycles in full-salinity seawater — sufficient for the complete operational service life of most ROV tooling programmes, observatory instrument maintenance schedules, and annual survey equipment deployments.
Q: What body materials are available for the BH25F?
A: Bulkhead body options include brass, 316L stainless steel, titanium, anodised aluminium, and PEEK. Titanium for CFRP hull interfaces and long-term corrosion resistance; PEEK for electrical isolation; 316L SS for general subsea deployment. Connector body is chloroprene rubber across all variants.
Q: What is the difference between BH25F and its In-Line counterpart IL25F?
A: The BH25F is a Bulkhead connector — used for panel/bulkhead feedthrough. The IL25F is a In-Line connector — it terminates a free cable and mates mid-run without requiring a panel mount. Most subsea systems use both types together as a mated pair.
Q: What inline cable is compatible with the BH25F?
A: Standard factory cable is 3 × 18 AWG, 0.82 mm² + 22 × 20 AWG, 0.52 mm² polyurethane. For alternative cable types, ODs, or custom conductor configurations, contact RV POWER GROUP for custom cable assembly options.
Q: What is the contact resistance specification for the BH25F?
A: Contact resistance is less than 10 mΩ per contact (< 0.01 Ω). Gold-plated brass contacts maintain this specification across 500+ wet mating cycles in seawater.
Q: Can the BH25F be used in freshwater or brackish water?
A: Yes. The BH25F is rated for all aquatic environments including freshwater, brackish water, and full-salinity seawater. The chloroprene rubber body and nitrile O-rings are chemically compatible with all natural water types, as well as common subsea hydraulic fluids and cleaning agents.
Q: Is pressure test certification available for the BH25F?
A: Yes — RV POWER GROUP can provide certified pressure testing to specific ocean depths on request. Test certificates, material certificates, and traceability documentation are available for defence, offshore, and certification-critical applications. Contact [email protected] for details.
Installation, Mating & Maintenance Guidelines
Pre-Mating Inspection
- Inspect both connector faces before every mating cycle — remove debris, biofouling, and salt crystal deposits from contact faces and locking sleeve surfaces
- Verify chloroprene body and nitrile O-rings are free of cuts, compression set, or surface damage — replace O-rings if any deformation is observed
- Check all 25 contacts are fully seated and free of corrosion, debris, or bent pins
- Apply a thin film of dielectric grease to O-ring sealing surfaces before deck-side (in-air) mating operations
Mating Procedure
- Align the keying feature precisely before applying axial load — force-mating a misaligned connector is the primary cause of contact damage in circular connectors
- Apply steady axial pressure until the locking sleeve engages fully with a positive click or thread engagement — verify full engagement before deployment
- For underwater mating: approach slowly to allow pressure equalisation across the contact face before final engagement
- Verify locking sleeve torque or snap engagement per the connector assembly specification before every deployment
Post-Recovery Maintenance
- Flush connector faces with fresh water immediately after recovery — chloride deposits accelerate oxidation on brass and gold contacts if allowed to dry
- Apply dielectric grease to contact faces and O-ring surfaces before extended unmated storage
- Inspect O-rings and contact faces after every 50 wet mating cycles or at 12-month intervals, whichever comes first
- Replace O-rings at 200-cycle intervals or if visual deformation, cracking, or compression set is observed
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