THROUGH HULL WITH VALVE 42x45

Function and technical context

The thru-hull with valve is a critical component of the seawater cooling system on boats with an inboard or inboard-tail engine: it passes through the hull below the waterline and regulates the passage of water to the cooling circuit or to other auxiliary systems. The integrated valve allows the inner circuit of the hull to be completely isolated, an essential function both during maintenance and in an emergency situation due to a hose break or water pump failure. Its dimensions of 42x45 mm determine its compatibility with the helmet thread and drill, so it is essential to verify the exact measurement before replacement. A thru-hull in poor condition or with a valve that does not close correctly represents a direct risk of water entering the bilge, compromising the buoyancy of the boat.

When to replace this part?

The most common symptoms that indicate that the thru-hull or its valve must be replaced are: difficulty opening or closing the valve (seizing due to galvanic corrosion or limescale deposits), presence of moisture or dripping around the body of the thru-hull, and visible deformations in the material due to aging or impact. It is recommended to inspect the thru-hull at each annual beaching, checking the free movement of the valve, the state of the seal with the hull and the absence of corrosion on the body. Replacing this element preventively during maintenance at the dock is much more economical and safer than facing a leak while sailing.

Compatibility table