Rubber Molded Bulkhead Connector - 3 Pin Male XSG-3-BCL

Rubber Molded Bulkhead Connector - 3 Pin Male XSG-3-BCL — Subsea Bulkhead Penetrator Connector for Pressure Vessels and ROV Housings

The Rubber Molded Bulkhead Connector - 3 Pin Male XSG-3-BCL is a panel-mount bulkhead connector designed to penetrate the wall of a pressure vessel, ROV housing, instrument housing, or diver equipment panel — providing a watertight electrical feedthrough at rated depth while allowing the in-line cable connector to mate and demate at the exterior face. The bulkhead body seals directly to the panel bore through a precision O-ring system, and the exterior face mates with the standard rubber moulded in-line connector series using the proven neoprene face-seal interface.

Available in Glass-Reinforced Epoxy body construction with 3/4-16 UNF mounting thread, this 3-contact bulkhead connector is engineered for permanent installation in ROV electronics housings, underwater lighting fixtures, sonar transducer bodies, and instrument pressure cases where a reliable, repeatable electrical penetration is required at rated pressure.

Key Design Features

• Glass-Reinforced Epoxy body — corrosion-resistant in seawater; compatible with aluminium, titanium, and acetal pressure vessel alloys; avoids galvanic coupling in multi-metal assemblies
• 3/4-16 UNF mounting thread — standard engineering thread; installs into tapped bore in pressure vessel wall; torque to specification with calibrated torque wrench
• O-ring panel seal — Buna N 70 Durometer O-ring in machined groove seals bulkhead body to vessel wall at rated pressure; face O-ring seals cable connector interface
• Gold-plated contacts — copper alloy, hard gold per ASTM-B-488; inboard contacts terminate to internal wiring; outboard face mates with rubber moulded in-line connector
• Mates with standard in-line connectors — compatible with RMG-FS, RMG-FS R/A, RMG-FS WOC in-line female socket connectors (same 3-contact series)
• Locking thread feature (BCL) — locking feature on exterior mating face prevents accidental cable connector unmating under vibration and ROV thruster turbulence
• Pigtail option — XSG-BCL-P variant includes factory-fitted internal pigtail leads for connection to internal PCB or terminal strip without soldering to bulkhead contacts
• Right-angle option — XSG-BCL-P-R/A provides 90° internal lead routing for space-constrained housings where straight-through wiring is not practical

Electrical & Mechanical Specifications

Typical Applications

• ROV electronics housing feedthrough — panel-mount connector on aluminium ROV pressure housing lid for external power and signal connection
• Subsea lighting fixture — bulkhead power feedthrough on LED underwater light body; allows lamp replacement without cutting cable
• Sonar transducer body — electrical penetration of sonar pressure housing for element wiring without machined metal connector complexity
• Instrument pressure vessel — feedthrough on CTD, ADCP, and data logger housings for external power and communication connection
• Diver equipment panel — helmet or backpack panel connector for umbilical attachment in surface-supply diving systems
• Underwater battery housing — sealed feedthrough on battery pressure vessel for charge port and load output in AUV and ROV battery pod designs
• Hydrophone array frame — bulkhead connector at array frame node for branch cable connection in moored hydrophone networks

Why Use a Dedicated Bulkhead Connector vs Cable Gland + Internal Terminal

Mate/Demate Without Breaching the Housing

A cable gland permanently bonds the cable to the housing — once the cable is gland-fitted, the housing must be opened to disconnect the internal wiring. A bulkhead connector allows the external cable to be mated and demated at the housing exterior without any internal access — enabling fast cable change, fault isolation, and system reconfiguration in the field without opening the pressure housing and exposing internal electronics to the environment.

Depth-Rated Electrical Feedthrough in One Component

A cable gland provides mechanical strain relief but no defined electrical rating — the internal wiring termination method (solder, crimp, terminal block) determines the electrical performance, and the gland/O-ring system determines the pressure rating. A bulkhead connector combines both functions in one tested assembly — defined contact resistance, insulation resistance, and pressure rating certified in a single component simplifying system compliance.

Standardised Mating Interface

All rubber moulded bulkhead connectors share a standardised face geometry with the in-line connector series — enabling any in-line female connector of the correct pin count to mate with any bulkhead of the same series. This standardisation eliminates the risk of using incorrectly specified cable glands or bespoke connectors that cannot be sourced for replacement in remote offshore operations.

Installation Instructions

Panel Bore Preparation

Machine the panel bore to the specified diameter and surface finish for the O-ring seal. Ensure the bore is clean, dry, and free of machining burrs before installation. Apply a thin film of silicone grease to the O-ring seal on the bulkhead body — this prevents O-ring extrusion during installation and ensures even compression at rated torque.

Torque to Specification

Install the bulkhead using a calibrated torque wrench set to the rated installation torque (3/4-16 UNF: 70 in-lbs for XSG series on dry metal threads). Over-torquing crushes the O-ring beyond its compression limit — causing the seal to extrude into the bore clearance and lose its sealing function. Under-torquing leaves the O-ring insufficiently compressed — the seal will fail at pressure before rated depth. Never estimate torque by feel — use a calibrated torque wrench.

Pressure Test Before Deployment

After bulkhead installation and internal wiring, pressure-test the housing to 1.5× maximum operating pressure with the external connector mated before first deployment. Verify no pressure decay over a 5-minute hold period. This test proves both the bulkhead body-to-panel seal and the connector face seal simultaneously under simulated deployment conditions — catching installation faults before the system reaches operating depth.