Posted on: October 7th, 2016 by Alex Wills

Exhaust Risers 

Soundown manufactures a wide range of exhaust risers, elbows, and spray rings to fit your application. From basic water injected elbows to high lift risers, these are a critical component of any marine exhaust system.

The water injected elbow, riser, or spray ring is a standard component of any wet exhaust system. It is here that the engine hot exhaust flow must get cooled before discharging from the boat without creating back pressure, noise, or vibration problems.

Soundown provides solutions that range from a simple spray ring that is flanged to meet up with customer-supplied riser piping to a complete riser system that includes bellows, isolation supports, and water injection.

Soundown supplies system-matched mixer designs based on specific water and gas volume flow rates delivered by the engine application, while maintaining pressure limits set by the manufacturer. The Soundown mixer provides rapid or short dwell cooling of the hot exhaust gases by means of special diffusion technology. The spray of cooling water is introduced into the hot exhaust stream as a fine perpendicular sheet of water for maximum coverage and heat transfer action in a very short flow distance. This is in contrast to conventional water injection, which is typically drilled hole, streams of water that travel parallel to the hot gas flow and take a greater amount of time and distance to mix together. These conventional water cooling delivery systems are more susceptible to insufficient cooling and hot zone problems as compared to the water sheeting delivery. It is noted that the abrupt “shock” cooling of the hot exhaust gas with the Soundown injection cooling causes a rapid increase in the gas density in the exhaust pipe, which reflects noise energy back toward the engine, resulting in reduction of exhaust noise levels before the silencer system.

Our mixers are fabricated for highest corrosion resistance for the wetted parts of the system by utilizing the special AL6XN duplex alloy in the construction. The hot riser, or lead-in section, to our water injection is fabricated from 316L stainless. It is fitted with conventional lace-on blankets, or the Hard Coat System, which has the thermal insulation material sealed to the pipe surface with a durable, baked-on, fiberglass epoxy composite system. The composite coat on the cold surface of the insulation allows for the assembly to be faired and paint finished to a high degree, much like our silencer systems.

For more information about configuring exhaust systems, view our exhaust systems and applications section.