Science of Silence
The Siphon Breaker plays a crucial role in a marine exhaust system, preventing the cooling water backing up into the engine when this is low in the hull.

The Halyard unit is cast from bronze, and incorporates a tapping point for some cooling water to be drawn off to feed the stern tube bearings.
• Material: Silicon Brass C87800, ASTM B176 and ASTM ZS144A and contains no Zinc

• Valve diameters: From ½” - 1”

• The U bend on the top of the unit will emit water occasionally. This can be drained overboard or in the bilge, but the hose must not under any circumstances be immersed in water at the bottom end or the water will siphon back up the system