GROCO Bronze Pipe Nipple - 4" NPT

The GROCO Bronze Pipe Nipple – 4" NPT is a cast bronze fitting engineered for applications requiring reliable fluid transfer and mechanical durability in marine, industrial, and plumbing systems. This 4-inch NPT pipe nipple delivers full flow capacity with a machined wrench flat that simplifies both installation and removal in tight working spaces or when tools are limited.

Manufactured from C83600 bronze—a copper-tin alloy chosen for its corrosion resistance in saltwater environments and resistance to dezincification—this fitting provides superior longevity compared to brass alternatives in offshore and coastal applications. The NPT × NPT threaded connection on both ends allows quick integration into existing piping systems without adapter fittings. The cast-in wrench flat eliminates the need for pipe wrenches on the body itself, reducing surface damage and speeding installation. Full-flow design ensures minimal pressure drop across the fitting, critical for maintaining system efficiency in high-volume transfer scenarios.

This nipple is suited for marine plumbing systems, seawater cooling loops, bilge systems, fuel transfer lines, and industrial process piping where bronze's antimicrobial and corrosion-resistant properties are essential. It is commonly specified in boat engine cooling systems, offshore drilling support equipment, and commercial fishing vessel installations. Note that C83600 bronze does not comply with NSF-61 certification and is therefore not approved for potable drinking water systems; it is intended exclusively for non-potable applications.

At 1 pound, this fitting is substantial enough to withstand vibration and pressure cycling without fatigue failure, yet manageable for field replacement. Stocking a 4-inch NPT bronze nipple ensures compatibility with standard marine and industrial thread gauges, making it a practical maintenance component for equipment servicing and retrofit projects.