1 In 4 Out Dome Splice Closure – High-Performance Fiber Optic Protection for Outdoor Networks
The 1 In 4 Out Dome Splice Closure is a high-reliability fiber optic cable management solution designed for outdoor, underground, aerial, and pole-mounted environments. Built to protect critical splicing points in modern broadband and FTTx deployments, this dome closure combines mechanical strength, water-tight sealing, and flexible internal cable routing. As operators continue expanding access networks and increasing split ratios, dependable closure systems become essential for maintaining low-loss connections and long-term network stability.
This technical page provides a complete professional breakdown of features, performance parameters, installation compatibility, material composition, internal structure, and integration with other fiber optic accessories such as patch cords, jumpers, PLC splitters, distribution boxes, and patch panels. It is crafted to support telecom procurement teams, project contractors, network designers, and distributors who require clear, detailed information before placing orders.
1. Product Overview
The 1 In 4 Out Dome Splice Closure is designed to accommodate one main fiber optic cable as the input and four branch cables as outputs. This configuration is widely used in mid-span branching, PON distribution, and access network expansion scenarios. The dome structure—often referred to as a “vertical closure”—is preferred for outdoor environments due to its superior sealing performance and resistance to water infiltration.
Featuring a multi-layered internal tray system, the closure supports a variety of splice combinations, including fusion splicing, mechanical splicing, and fiber management with PLC splitters. The internal organizer ensures stable routing of fibers, minimizes micro-bending, and maintains the minimum bend radius required for high-bandwidth optical performance.
2. Structural Design
2.1 Dome Housing
The exterior housing is manufactured from premium-grade, UV-stabilized polypropylene (PP) or polycarbonate (PC). These materials provide:
High impact resistance
Excellent aging performance
Protection against corrosion
Flame-retardant capabilities
Strong resistance to temperature fluctuations
The dome structure is reinforced with stainless steel locking bands, which compress the sealing ring evenly and ensure an IP68-rated closure even in extreme outdoor conditions.
2.2 Baseplate and Port Layout
The base of the closure incorporates:
1 large circular input port for main feeder cable
4 smaller output ports for branch drop cables
Each port uses built-in rubber grommets or heat-shrink sleeves (depending on model) to maintain a tight seal around varying cable diameters. The design supports both dielectric and armored cables.
2.3 Internal Splice Tray System
Inside the closure, a stacked tray system organizes splices, buffers, and splitters. Each tray features:
Individual splice holders
Hinged design for easy access
Cable tie points
Clear fiber routing channels
Depending on configuration, the closure may support:
24, 48, 72, 96, or more fusion splices
Several mini-type or steel-tube PLC splitters
Mid-span fiber extraction without cutting all fibers
3. Technical Specifications
Below is the detailed parameter list suitable for engineering calculations and procurement evaluations.
3.1 Mechanical Specifications
Dimensions: 480–520 mm (height), 180–220 mm (diameter) depending on model
Weight: Approx. 2.8–4.5 kg
Material: High-strength polypropylene (PP) / polycarbonate (PC)
Color: Black UV-resistant finish
Sealing Method:
Mechanical seal with rubber O-ring
Stainless steel reinforcement bands
Optional heat-shrink port adapters
Cable Port Count:
1 main input
4 branch outputs
Cable Diameter Range:
Feeder: 10–22 mm
Distribution: 5–14 mm
Splice Capacity:
Standard: 24–96 fibers
Max with extended trays: up to 144 fibers
3.2 Environmental Performance
The closure is tested to withstand extreme environmental stress:
Operating temperature: –40°C to +75°C
Storage temperature: –50°C to +85°C
Humidity resistance: 100% at 40°C
Waterproof rating: IP68, suitable for underground burial
UV resistance: Meets outdoor exposure standards
Corrosion resistance: Resistant to acids, salts, and alkali
3.3 Optical Performance
Fiber Types Supported:
G.652D
G.657A1 / G.657A2
ITU-T standard single-mode fiber
Insertion Loss (splice): ≤0.1 dB typical
Return Loss: ≥ 60 dB (fusion splicing)
Bend Radius (internal routing): ≥30 mm
3.4 Compatibility With Network Accessories
The closure is designed to integrate seamlessly with fiber optic components used in distribution networks, such as:
Fiber optic patch cords
Fiber optic jumpers
PLC splitters (1×2, 1×4, 1×8, 1×16, 1×32)
Wall-mounted distribution boxes
Rack-mounted patch panels
ODF frames
Cable glands and protective sleeves
4. Application Scenarios
The 1 In 4 Out Dome Splice Closure is highly versatile and supports multiple cable deployment methods, making it ideal for:
4.1 FTTH / FTTx Networks
Commonly used for branching off distribution fibers to serve multiple homes or buildings.
4.2 Feeder Cable Mid-Span Splicing
Allows engineers to open feeder cable jackets, extract specific fibers, and leave the remaining fibers undisturbed.
4.3 Outdoor PON Systems
Supports GPON, EPON, and XG(S)-PON architectures with PLC splitter integration.
4.4 Aerial Installation
Can be installed on poles or messenger wires using stainless steel brackets.
4.5 Underground and Manhole Installations
Its IP68 waterproof rating makes it suitable for direct burial or placement in handholes.
4.6 Telecom and CATV Infrastructure
Ideal for backbone expansion, fiber refactoring projects, and network upgrades.
5. Internal Configuration
5.1 Splice Tray Options
Customers can customize the internal setup:
4-tray set (24–48 splices)
6-tray set (48–72 splices)
8-tray set (72–96 splices)
Extended 12-tray set (up to 144 splices)
Each tray includes fusion splice protectors, fiber routing paths, and jumper storage guides.
5.2 PLC Splitter Integration
The closure supports installation of:
Mini-type PLC splitters
Bare fiber PLC splitters
Steel tube PLC splitters
Routing guides ensure low bending losses and protection from mechanical stress.
5.3 Cable Management
The closure provides:
Strength member clamps
Kevlar fixing points
Buffer tube organization rings
Slack storage areas
All fibers maintain safe bend radii to preserve optical performance.
6. Installation and Maintenance
The closure is engineered for efficient deployment:
6.1 Installation Steps
Prepare cable sheath and clean all fibers
Install sealing grommets or heat-shrink sleeves
Fix cable strength members to the frame
Route buffer tubes through guides
Complete fusion splicing
Organize fibers in trays
Position trays in stacked configuration
Apply sealing ring and lock dome housing
6.2 Maintenance Benefits
Open-and-close design allows re-use
Each tray is individually accessible
No need to disturb existing fibers
Long service life (10–25 years depending on environment)
7. Advantages for B2B Buyers
The 1 In 4 Out Dome Splice Closure offers several advantages for wholesalers, project integrators, ISPs, and telecom operators:
Cost Efficiency
High capacity and durable construction reduce replacement and maintenance costs.
Flexible Deployment
Suitable for all environmental conditions and cable types.
High Compatibility
Works seamlessly with PLC splitters, fiber jumpers, patch cords, distribution boxes, and patch panels.
Strong Sealing Performance
Ensures network reliability even during storms, floods, or underground conditions.
Standardized Design
Matches global telecom standards, making it easy to integrate into existing networks.
