GROCO 4" Bronze Flanged Seacock & Adaptor w/3" NPT Side Port

The GROCO 4" Bronze Flanged Seacock & Adaptor with 3" NPT Side Port (model SBV-4000-P) is a heavy-duty through-hull seacock engineered for marine cooling systems, air intake manifolds, and raw-water applications on offshore fishing vessels and cruising sailboats. Cast from C84400 bronze—a marine-grade alloy selected for its superior corrosion resistance in saltwater environments—this seacock maintains full flow capacity while delivering the reliability demanded by serious boaters who operate far from the nearest haul-out facility.

The 4-inch flanged body accepts standard bolt patterns for secure through-hull installation, while the 3-inch NPT side port provides a connection point for stainless steel check valves (SSCV) or other NPT-threaded marine accessories. The seacock's handle features a square hole that accepts a standard ratchet, allowing crews to operate stuck or hard-to-reach valves without straining—critical during rough-weather scenarios or emergency shutdowns. Two driver ports permit handle relocation to suit your vessel's plumbing layout, and the entire valve mechanism remains serviceable while installed, eliminating the need to haul the boat for routine maintenance.

This seacock is specified by serious cruisers, offshore anglers, and commercial operators who cannot tolerate cooling system failures. The bronze construction outlasts cheaper alternatives in tropical and high-salinity waters, and the full-flow design minimizes pressure drop—particularly important for engine and hydraulic cooling circuits where restriction can lead to overheating. Whether you're upgrading an older raw-water system or outfitting a new build, the GROCO 4" seacock delivers the corrosion resistance, ease of maintenance, and operational reliability that distinguish professional-grade marine systems from mid-range offerings.