Tackling Corrosion And Leakage On Ships Ultrasonically

Cygnus Instruments was born in the marine industry, working alongside ship surveyors and commercial divers to this day. Four decades on, this knowledge of the industry and its challenges is second to none. Cygnus is world renowned as the inventor of easy-to-use, highly accurate ultrasonic testing (UT) equipment.

Solution to scrubber corrosion

Exhaust Gas Cleaning Systems (EGCS) – more commonly known as “scrubbers” – are installed on thousands of vessels worldwide in order to comply with the IMO 2020 Sulphur Cap. They have not been without some issues, including EGCS corrosion. The wash water from scrubbers, now containing pollutants it has filtered, is acidic and highly corrosive. The effects of the acidic nature of the corrosive scrubber wash water on the integrity of the ship are further aggravated by the high temperatures of exhaust gases.

It is now firmly established that the structural integrity of the scrubber and associated pipework (e.g. SOx scrubber discharge water line) need to be regularly checked for signs of corrosion.

Ultrasonic thickness gauging is a simple, cost-effective, and reliable method to proactively engage with a schedule of preventative maintenance on scrubbers. Areas of particular interest and concern for vessels are the scrubber discharge outlet and the overboard pipe.

Cygnus 6+ Pro boasts an array of intuitive features, including three measuring modes, live A-Scan, B-Scan, and Radial Points function for further investigation on heavily corroded areas. The A-Scan display allows visual verification of back-wall echo signals and manual adjustment of gain. What’s more, the 6+ has a comprehensive data-logging feature that records your measurements for hassle-free reporting and post-analysis.

Hatch cover weathertightness

Cygnus has applied its knowledge of the marine industry and ultrasonic expertise to a different angle and engineered a fast, effective solution for evaluating cargo hatch covers and watertight seals to determine water leaks and weather tightness. The Cygnus Hatch Sure Ultrasonic Leak Detector is ABS type approved and accepted by P&I clubs. It cleverly conducts inspections with cargo in place.

Compared to traditional testing methods like host or chalk testing, Cygnus Hatch Sure is more time-efficient and cost-effective for testing bulk cargo carriers. Its powerful, robust transmitter contains 19 ultrasound emitters (40 kHz) with 6 selectable pre-set power levels to adjust to the scale of the test area, including confined spaces. For such spaces, the system is an extremely lightweight kit, with a built-in neck and wrist straps for hands-free operation.

In addition, Cygnus Surface Range of thickness gauges all read through coatings of up to 20mm thick – which means there is no need to remove any of the important (and expensive) protective coatings or epoxy that safeguard against external scrubber corrosion. And, for heavily corroded metals with a thin or no coating left, Cygnus PLUS gauges incorporating Echo-Echo and Single-Echo measuring modes coupled with the Measurement Stability Indicator (MSI™) can give the quick and reliable readings you need.