The application characteristics of press connectors in underwater equipment

press connectors, as a type of device that achieves electrical connections through mechanical pressure, are widely used in underwater equipment due to their unique structural and performance advantages. Underwater environments (such as high pressure, corrosion, humidity, space constraints, etc.) impose extremely high requirements on the reliability of connectors. press connectors need to be specifically optimized to meet these challenges. The following are its core application features:

1. High sealing performance: The core guarantee for water resistance and anti-permeation

The fatal risk of underwater equipment is the infiltration of water or corrosive liquids into the interior. Therefore, press connectors must have a fully sealed structure. Its design usually incorporates multiple sealing mechanisms:

• Interface sealing: High-elastic materials (such as silicone rubber and fluorine rubber O-rings) are used to form a static seal at the junction of the male and female ends of the connector, preventing liquid from seeping along the connection surface.

• Internal sealing: The crimping areas of the wires are potting with insulating materials (such as epoxy resin, polyurethane) or processed by molding to prevent water from seeping in through the wire gaps. Some high-end products adopt "air seal" technology (such as the close combination of metal and ceramic), which can withstand penetration under deep water and high pressure.

• Material compatibility: The sealing material and the casing material (such as stainless steel, titanium alloy) should have a matching coefficient of thermal expansion to prevent seal failure caused by temperature changes (such as from low temperature in the deep sea to high temperature in the hydrothermal zone).

2. High pressure resistance: Adaptable to deep-sea pressure environments

For every 10-meter increase in underwater depth, the hydrostatic pressure approximately increases by 1MPa (100 meters ≈10 atmospheres). press connectors need to resist high-pressure deformation through structural design:

• High-strength housing: Made of titanium alloy, stainless steel (such as 316L) or reinforced plastic (such as PEEK), it ensures that the housing does not deform under water pressure and protects the internal crimping interface and seals.

• Compact structure: Reduce the volume of the casing to lower the pressure-bearing area, while optimizing the internal layout (such as shortening the reserved length of the wires) to prevent the loosening of the crimping points caused by the stretching of the wires under high voltage.

• Pressure balance design: Some connectors are equipped with built-in elastic membranes or vent holes (in combination with waterproof breathable membranes) to balance the pressure difference between the inside and outside, reducing the risk of the housing being squeezed.

3. Corrosion resistance: Dual protection of materials and processes

The high salinity of seawater, microbial adhesion and chemical corrosion (such as sulfides) can accelerate the oxidation of metals. The anti-corrosion strategies of press connectors include:

• Material selection: The shell is preferred to be made of titanium alloy (with better corrosion resistance than stainless steel) or copper alloy coated with precious metals (such as gold or nickel plating) on the surface to enhance resistance to galvanic corrosion and pitting corrosion.

• Insulation component protection: Use engineering plastics that are resistant to hydrolysis and chemical corrosion (such as PBT, LCP) to prevent the insulation layer from absorbing water or being eroded by seawater, which could cause creepage or short circuits.

• Pore-free design: The crimping area has no thread or welding gap, reducing the "dead zone" where corrosive media can remain and lowering the risk of local corrosion.

4. High-reliability connection: Anti-vibration and long-term stability

Underwater equipment is often affected by ocean currents, mechanical movement or the vibration of the equipment itself. Connectors need to be prevented from loosening or increasing contact resistance.

• Crimping process control: By using dedicated crimping tools (such as hydraulic pliers, automatic crimping machines), ensure that the crimping force between the wire and the terminal is consistent, forming airtight crimping points (without residual oxide layer), reducing contact resistance and inhibiting electrochemical corrosion.

• Anti-loosening structure: The male and female ends adopt a snap-on, threaded locking or spring clamping design to prevent axial displacement caused by vibration. Some products have added secondary locking (such as safety pins) to enhance their impact resistance.

• Low contact resistance: The terminal surface is silver-plated or gold-plated (thickness ≥3μm), reducing the impact of oxide layers on electrical conductivity and ensuring long-term stability of signal/power transmission (such as maintenance-free for more than 10 years).

5. Installation convenience: Adaptable to the limitations of underwater operations

The maintenance cost of underwater equipment is extremely high (such as in diver operations or ROV operations), and press connectors need to support rapid installation and disassembly:

• Tool simplification: Some connectors are designed as "plug and play", requiring only manual or simple tool crimping (such as pre-crimped terminals + quick locking structure), reducing on-site operation time.

• Modular design: Integrates multi-core functions (such as 12-24 cores), reducing the number of interfaces; Some products support blind insertion (in combination with guide keys), reducing the difficulty of underwater alignment.

• Repairability: When a single-core fault occurs, the crimping terminals can be replaced separately without the need to replace the entire connector, reducing maintenance costs.

6. Special Scenario Adaptation: Dealing with extreme environments

For special underwater scenarios (such as hydrothermal vents, polar cold waters, and areas with high biological attachment), press connectors need to be further optimized:

• Wide temperature resistance range: The material needs to adapt to temperature fluctuations from -2℃ (polar) to 400℃ (hot liquid outlet) to avoid structural failure caused by thermal expansion and contraction.

• Anti-biofilm adhesion: Apply antifouling agents on the surface (such as silver ion-containing coatings) or use smooth materials (such as titanium alloys) to reduce the impact of algae and shellfish adhesion on sealing and contact performance.

• Anti-radiation/electromagnetic interference: When used in nuclear-powered underwater equipment or high-frequency signal transmission, the casing must have shielding function (such as metal braided layer), and the crimping terminals need to optimize impedance matching.

Summary

The core advantages of press connectors in underwater equipment lie in its high sealing performance, high pressure resistance, corrosion resistance and rapid installation. However, its reliability is highly dependent on material selection, crimping process and structural design. With the advancements in deep-sea exploration, Marine energy development and other fields, in the future, press connectors will develop towards higher pressure ratings (such as 110MPa deep-sea applications), intelligence (such as integrated condition monitoring sensors) and environmental friendliness (lead-free coatings, recyclable materials).

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Nanjing Junhong Signal Equipment Co., Ltd.