Attwood 1.5 in 316 Stainless Barbed Scupper Valve

The Attwood barbed scupper valve is cast from corrosion-resistant marine metal for long-term strength in above-waterline plumbing installations. Visible surfaces are polished to a mirror finish and then passivated for additional protection. Thick sidewalls are designed to tolerate hose movement and repeated clamping without the flexibility associated with plastic fittings. This version uses a neoprene flap with a molded V that seats in the body groove to help reduce backwash.

A silicone gasket and a channel beneath the flange help the installer place sealant neatly and create a more consistent deck or hull seal. Wrench flats or an end notch provide a solid gripping surface so the fitting can be tightened from inside the hull by one installer. The barbed tail leaves room for multiple hose clamps, which is important on critical drain and plumbing connections. The polished flange also gives the exterior installation a finished appearance that matches other polished deck hardware. The flange measures 3 in across, with a 1-7/8 in thread diameter, 3-1/2 in thread length, and 1-1/2 in barb length. Overall length is 5-1/2 in, the recommended installation hole is 2 in, and the body accommodates hull material up to 3 in thick. The neoprene flap uses a molded V that seats into the grooved body to help reduce backwash.

• Heavy-duty corrosion-resistant construction
• Mirror-polished and passivated exterior surfaces
• Silicone gasket and sealant channel aid installation
• Barbed tail provides room for multiple hose clamps
• Designed for above-waterline installation only

Dry-fit the component before applying sealant so the hose routing, thread engagement, and available hull thickness can be confirmed. After installation, inspect the clamps and seal periodically because any thru-hull or scupper connection can become a leak point if hardware loosens. For compatible replacement parts and related equipment, browse more Thru-Hulls & Drains.