Split Flange Adapters

How Hydraulic Split Flange Fittings Work?

The 4-bolt split-flange design is widely used internationally as a standard connection method for high-pressure hydraulic systems. Two split flange halves clamp down on the port surface and compress an O-ring into a machined metal groove in the flange head. The flange head then makes metal-to-metal contact with the port surface, leaving no pathway for the O-ring to extrude or deform under pressure. The result is a high-integrity seal that maintains leak-free performance under the pressure cycling, vibration, and dynamic loading common in mobile and industrial hydraulic applications.
Code 61 and Code 62 flange adapters follow SAE J518 dimensional standards, with Code 62 rated for higher operating pressures than Code 61. Selecting the correct code for the application's pressure rating is a critical specification step when sourcing split flange hydraulic fittings.

When to Use Hydraulic Split Flange Adapters

Split-flange fittings are the right choice in specific situations where threaded fittings fall short. If any of the following describe your application, split flange adapters are likely what you need:

Large Bore, High-Pressure Connections

At larger port sizes and higher system pressures, threaded connections become increasingly difficult to seal reliably and require significant torque to assemble. Split-flange connections distribute clamping force evenly around the port via four bolts, making them the preferred connection type for large-bore hydraulic lines in high-pressure systems.

Hose Alignment in Tight Spaces

Split flange fittings allow the hose assembly to be positioned and oriented before the flange bolts are fully tightened, a meaningful advantage in confined installation environments where hose routing flexibility is limited. This is a common requirement for construction equipment, agricultural machinery, and mobile hydraulic platforms, where the available space around the hydraulic ports is restricted.

Hose Replacement Without Cutting Expensive Fittings

Once split-flange adapters are installed on the ports, hose assemblies can be replaced with standard hose swivel ends, eliminating the need to replace the flange fitting itself each time the hose is serviced. This reduces the cost of routine hose maintenance and makes field replacement faster and more practical.

OEM Equipment Design

OEM equipment manufacturers specify split-flange ports on pumps, motors, valves, and hydraulic blocks, where the 4-bolt flange standard provides a robust, internationally recognized connection interface. Code 61 and Code 62 flange adapters are the standard method for connecting hose assemblies to these ports across construction, agricultural, industrial, and mobile equipment platforms.

Common Applications

UPC's Code 61 and Code 62 flange adapters are specified across the following industries and applications:

• Construction equipment — Excavators, skid steers, cranes, and hydraulic attachment circuits with large bore, high-pressure connections
• Agricultural machinery — Tractors, combines, and hydraulic implement circuits where hose serviceability and field replaceability matter
• Mobile hydraulic equipment — Telehandlers, aerial work platforms, and utility vehicles with confined hydraulic routing
• Industrial hydraulic systems — Presses, injection molding machines, and power units with high-flow, high-pressure port connections
• OEM hydraulic system design — Pump, motor, and valve connections on new equipment builds following SAE J518 flange standards
• Hose assembly and repair shops — Replacement adapters for field and shop hose service on equipment with existing flange ports

Split Flange Adapter Categories

Split Flange Adapters: JIC & O-Ring Face Seal (OFS)

Code 61 and Code 62 split-flange adapters convert flange ports to JIC or O-Ring Face Seal connections, available in ½" through 2" sizes for the most common hydraulic hose assembly end configurations.

Split Flange Adapter Accessories

Flange halves, bolts, O-rings, and related hardware and accessories for assembling, completing, or servicing split flange connections, stocked to support both new installations and field repair requirements.

In Stock & Ready to Ship Across the Upper Midwest