ULP #12 O-Ring Boss Fitting

The ULP #12 O-Ring Boss Fitting from XRP-XTREME RACING PROD. is a precision hydraulic line connector engineered for high-performance fuel and coolant systems in race-built and modified vehicles. This fitting type is essential for builders who demand leak-free connections under extreme pressure conditions, vibration, and thermal cycling that exceed OEM specifications. Whether you're assembling a competition engine bay, upgrading fuel delivery systems, or constructing custom cooling circuits, the O-ring boss design delivers the reliability required in motorsports and street performance applications.

The ULP #12 designation indicates a size-specific SAE fitting standard compatible with #12 hose and line configurations commonly found in fuel injection systems, turbo cooling lines, and custom plumbing applications. The O-ring boss design creates a metal-to-metal seal reinforced by an elastomer O-ring, eliminating reliance on thread-form sealing alone and dramatically reducing the risk of weeping or catastrophic failure under sustained pressure spikes. XRP's manufacturing standards ensure dimensional accuracy and surface finish consistency that allows proper O-ring compression and system integrity across repeated thermal cycles—critical for turbocharged, supercharged, and high-RPM powerplants where conventional fittings prove inadequate.

Professional engine builders, fabricators, and enthusiasts restoring or modifying high-output vehicles benefit from pairing these fittings with quality braided stainless steel hose and complementary XRP system components. Installation requires careful O-ring selection and proper torque specification to avoid over-compression or under-sealing; reference manufacturer guidelines for your specific application. The lightweight design (0.17 lbs) minimizes ancillary weight in engine bays where every fraction counts, making this fitting ideal for road race, drag strip, and street-performance builds where durability and precision matter.