Ultrasonic testing for Subsea Structures and Ship Surveys

High levels of salt contained in seawater and sea air is responsible for exacerbating severe corrosion – a relentless threat to the integrity of marine structures and vessels. Salt promotes the chemical deterioration of exposed surfaces and the growth of corrosive organisms. The worst is amidst alternating wet and dry conditions, usually at the water’s surface – the ‘ splash zone ’.

Regular, accurate inspection and maintenance are essential for ensuring the safety of an extensive list of structures compromised by marine corrosion – from offshore platforms, underwater structures, oil rigs, bridges, piers and pontoons to ship hulls, canal locks, offshore wind turbines and subsea pipelines.

 

Cygnus Underwater – the original diver-held subsea multiple-echo ultrasonic thickness gauge

Still the industry standard today and the top choice for divers nearly 4 decades on, Cygnus Underwater gauge is designed to be a rugged, reliable ultrasonic testing instrument that performs accurate subsea maintenance and surveys under hostile conditions. Like all Cygnus instruments, it employs the multiple-echo technique for through-coat measurements. It is depth-rated to 300m with a bright LED display, ideal for poor visibility and offers topside repeater options.

Being so versatile, this unit is the perfect fit for diver-accessible inspection on subsea structures and Underwater Inspection in Lieu of Dry-Docking (UWILD) surveys – marine vessels inspected in operation to reduce downtime, travel time and cost.

 

The ideal solution for areas inaccessible to divers

Many subsea structures sit in tight spaces, extreme depths or poor visibility, making accurate thickness gauging inspection difficult, sometimes impossible for divers. For instance, as the search for oil and gas is forced into deeper waters, subsea pipelines are becoming unsafe for divers to reach, yet regular inspection remains crucial. Not to mention hot, corrosive fluids running through cold pipes triggers fast cooling and threats of rupture with damaging environmental consequences.

The Cygnus Mini ROV Mountable thickness gauge can facilitate key preventative inspection. Specially designed to be mounted onto small observation ROVs with or without a manipulator facility, it allows the operator to carry out ultrasonic thickness measurement (UTM) in areas previously unfeasible using larger ROVs or divers. With the renowned ‘ Multiple Echo’ technique at its core, it can achieve extremely fast and accurate measurements through coatings, therefore perfectly paired for use with ROVs as minimal surface preparation is required. The unit is pressure tested to 500m (1,640ft) – suitable for most UTM NDT inspections underwater.

 

Cygnus’ first-class subsea range offers the flexibility necessary to navigate subsea inspection challenges, all with a 3-year warranty!