Hans Jensen Lubricators (Denmark) have experienced increased demand for their recently introduced Swirl Injection Principle (SIP) cylinder lubrication system for 2-stroke marine diesel engines. Within two years, more than 100 vessels have begun to use this lubrication system. The SIP enables reduction of cylinder oil consumption while maintaining highly satisfactory cylinder condition compared to conventional methods of lubrication. It can be applied to all three major engine designs i.e. MAN B&W, Wärtsilä-Sulzer and Mitsubishi, with equal benefits.

SIP unique lubrication method allows an even distribution of the cylinder oil on the upper part of the liner wall. The cylinder lubricator pumps the oil to the SIP valves mounted in the cylinder liner wall. The valves are equipped with nozzles for spraying tiny droplets of cylinder oil covering a large area above the next injection valve.

Spraying from all valves ensures covering the entire circumference of the cylinder liner. The injection takes place when the exhaust valve is closing and well before the piston passes the injection quills in the upward movement. The centrifugal power of the scavenging air swirl ensures that the droplets settle horizontally well distributed on the liner wall. This allows the piston rings to make the vertical distribution of the injected cylinder oil when they pass in the continued upward movement. Thus, an optimal distribution of cylinder oil is attained with a minimum of oil quantity injected.

The SIP system design allows retrofit application with advantages similar to those obtained in newbuildings. According to the company, reduction in cylinder oil consumption by 60% has been experienced, with hardly any liner wear (below 0.02 mm/1000h), and extended lifetime of piston rings.