#4 Male Flare Tee to Fem Swivel On Run Fitting

The #4 Male Flare Tee to Fem Swivel On Run Fitting is an essential hydraulic connector for marine fuel systems, cooling lines, and pressurized applications on boats and watercraft. After decades on the water, any serious boater knows that reliable fuel and fluid transfer is non-negotiable—a single fitting failure at sea can compromise engine performance or create safety hazards. This male flare tee configuration allows you to branch off a fuel or coolant line while maintaining a secure, swivel connection on the run line, eliminating the need for bulky manifold blocks and simplifying system layouts in tight engine compartments.

Engineered with a size #4 flare specification, this fitting uses a proven 37-degree flare seat design that creates a metal-to-metal seal without requiring tape or sealant—critical for fuel applications where chemical compatibility and leak-free operation are paramount. The male flare end connects to your primary fuel or coolant line, while the integrated female swivel coupling accommodates a secondary run line with full 360-degree rotation, preventing hose kinking and fatigue cracking common in high-vibration engine environments. The swivel feature distributes stress evenly, extending the service life of connected hoses and reducing maintenance downtime during the boating season.

This fitting suits retrofit projects and OEM replacements on both inboard and outboard marine engines, particularly where space constraints or existing line routing demand a compact tee solution. Boaters upgrading fuel systems, installing new gauges, or replacing corroded fittings will appreciate the durability and leak-free performance that proper flare fittings deliver—especially on long-distance cruises or offshore runs where system reliability is non-negotiable. Ensure your flare tool and hoses match #4 sizing for a secure, pressure-tight assembly that will serve reliably across seasons.