Drain Valve for Inflatable Boats – Non-Return Drain Plug 6 x 4 cm (Grey PVC)

This drain valve for inflatable boats is designed to make it easy to empty out any water that accumulates inside your boat, while also preventing that water from coming back in. The valve consists of two main parts – an outer base flange and an inner plug piece with a locking mechanism. The flange mounts on the transom or an appropriate drain hole in the boat’s hull, and the plug screws into it, creating a watertight seal.

Construction and features:

• Two-piece design with non-return flapper: Inside the drain opening is a built-in rubber flap (one-way valve) that opens outward to let water out and automatically closes when there’s external pressure. In practice, when the boat is moving and water flows toward the drain, the flapper opens; when the boat is stationary or waves press from outside, the flapper shuts to prevent backflow into the hull.
• Sealing O-rings for security: Both the flange and the plug have rubber O-ring gaskets that ensure a waterproof seal. Even in rough conditions or rocking motion, the closed valve will not let water seep inside.
• Easy water release: This drain plug is especially useful after rain or heavy spray has collected water in your boat. You can simply tilt the boat or get it on plane, and water will escape out of the open valve. When you need the hull completely sealed – for instance, before launching or if leaving the boat in the water – you can screw the plug tightly closed with a few turns.
• Rugged, durable material: The valve’s body is made from high-quality PVC, which is resistant to impact, abrasion, and UV rays. This makes it suitable for long-term use in saltwater or freshwater without cracking or degrading. The rubber flapper and attached lanyard are also marine-grade, meaning they won’t corrode and will retain flexibility over time.
• Size and installation: Its compact dimensions (about 6 cm overall length and 4 cm inner diameter) allow installation in various locations – most commonly on the inflatable’s transom (the stern board). Installation requires cutting or using an existing hole of the appropriate diameter; the valve’s two pieces sandwich the boat fabric between them as they are screwed together. It’s recommended to apply a marine sealant (e.g., Sikaflex) around the flange during installation to ensure a completely leak-proof fit.

Applications and benefits:

• Safety and convenience: With this drain valve, you can quickly evacuate any water inside the boat after a rainstorm or when pulling the boat out, without having to flip the boat over or manually bail it out. It saves time and effort, especially for larger inflatables.
• Automatic drainage under way: In some setups, the valve can be left open while running – when the boat is on plane, any interior water will continuously drain out, and the flap will block incoming water from the stern. This means your cockpit can self-bail to an extent during operation.
• Universal compatibility: The flange diameter (~45 mm) is a standard size for many models. This product is suitable both as a replacement for an old, leaky drain and as an upgrade for boats that previously lacked a proper drain.
• Low maintenance: The plug is equipped with a small cord that tethers it to the base, so you won’t lose it overboard. After use, simply screw it closed to make the boat watertight again. If sand or salt accumulates on the flapper, a quick rinse with fresh water will ensure it continues to seal properly.

With this inflatable boat drain valve, you ensure a dry floor and a more comfortable boating experience. It’s a small but crucial component for any inflatable dinghy, enhancing safety and convenience by eliminating the hassle and hazard of accumulated water inside your boat.