Inflatable Boat Drain Valve – Ø45 mm One-Way Drain Plug

Code:

02199-36

Boat Drain Valve – Ø45 mm One-Way Drain Plug

A one-way drain valve (non-return plug) for inflatable boats with a Ø45 mm transom hole. It allows easy draining of water from the boat without letting it flow back in. Features:

Two-Piece Design: Includes an inner and outer part that screw together through the transom, forming a tight, reliable seal.
Auto Close Flap: Features a built-in rubber flapper that automatically closes to prevent backflow, allowing water to exit but not re-enter.
Universal Ø45mm Fit: Fits standard drain openings of about 45 mm diameter (flange ~60 mm) – suitable for most RIBs and inflatables with a factory transom drain.
Rugged Build: Made of durable plastic (ABS/nylon) with a brass pivot, resistant to impact, saltwater, and UV exposure for long service life.

Price: 17⁰⁰лв. €8⁶⁹

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This non-return drain valve is an extremely handy accessory for any inflatable boat or RIB, as it makes it easy to drain out any water that accumulates inside (rainwater, splashes) while underway or when lifting the boat out. The valve features a two-piece assembly: an outer part (outside on the transom) and an inner part (inside the boat) that screw together. This through-transom attachment creates a watertight, secure fit with no risk of the parts loosening under vibration.

Non-Return Mechanism: Inside the valve is a rubber flapper that acts as a one-way check valve. When water inside the boat pushes against the flapper (for example, as you accelerate and water flows toward the transom), the flapper opens outward, allowing water to drain out through the Ø45 mm opening. However, if water from outside presses on the flapper (such as when the boat is stationary or a wave hits the transom), the membrane automatically seals shut, preventing any backflow into the boat. This keeps your boat’s interior dry without the need to constantly insert or remove drain plugs.

Installation: The valve is designed to fit standard factory drain holes (~45 mm) in the transom board. To install or replace it:

Remove the old drain plug/valve if present. Clean the hole of any old sealant or debris.
Position the new valve – the inner section has a rubber gasket that should sit flush against the inside of the transom. Align the outer section on the outside.
Gently screw the two parts together through the hole. Hand-tighten until the gasket is compressed and the fit is snug, but avoid over-tightening (to prevent stripping threads or distorting the gasket). When properly tightened, the inner and outer flanges should sit evenly against the transom surfaces.
Test with water: pour some water inside the boat and observe if it drains out and that no water seeps back in. If needed, tighten a bit more to ensure no leaks.

Usage & Maintenance: Under normal conditions, the valve can remain installed and left open – the automatic flapper will stop water from entering when the boat is at rest. For faster drainage, make sure the flapper area is clear of debris (sand, weeds) that could hinder its closing. After each boating season, rinse the valve with fresh water to remove salt and grime. The rubber flapper can be accessed for cleaning or replacement if it loses elasticity over time (spare flappers are available separately). Keeping the mechanism clean ensures the valve continues to operate smoothly, reliably expelling water and blocking incoming waves.