Ultrasonic Watertight Hatch Cover Testing

Welcome to Coltraco Ultrasonics’ range of Ultrasonic Watertightness and Leak Detection Systems. 

We pride ourselves on the quality, reliability, and accuracy of our instruments – all made in the UK. 

Our watertight integrity leak detectors use ultrasound to monitor the watertight integrity of any room or compartment, with the capability to locate leak sites as small as 0.5mm in diameter. They are commonly used for watertight integrity testing of hatch covers, watertight doors, multi-cable transit (MCT) areas across bulkheads in marine structures. 

Ultrasonic Watertight Integrity Testing 

Our Portascanner® range of ultrasound testing systems are powerful, portable tools to aid you in your watertight integrity testing procedures.  

Why choose Ultrasonic Watertight Integrity Testing?

Unlike alternatives such as hatch cover hose testing, ultrasonic leak testing is quick and non-invasive, allowing you to check for leaks in a matter of minutes with practically no impact on the normal operation of your facilities. 

Ultrasound enables a reliable and scientific way to assess watertightness. By contrast, chalk testing is easily falsified. The Portascanner® WATERTIGHT TOUCH is the world’s first ultrasonic leak detector that is also capable of quantifying the physical extent of individual leak sites and determining the flow rate of water through them. Our leak-size quantification algorithms have been independently tested and verified by the National Physical Laboratory, meaning you can understand and quantify the risk posed by each leak or seal. 

The Portascanner® WATERTIGHT TOUCH contains in-built imaging and reporting functionality to make the surveying process as smooth as possible. Technical support, training, and advice is available throughout the lifetime of the unit and we are here to help you with your application. 

How does Ultrasonic Leak Detection Work? 

Ultrasonic leak detection takes advantage of fundamental characteristics of sound waves to identify and precisely locate water leaks in any structure. It makes use of the reflection and absorption behaviour of sound waves when incident on a boundary between a solid structure and the air adjacent to it. 

Ultrasonic leak detectors are comprised of two main components: an ultrasound generator and a receiver unit. The generator is placed on one side of a structure and switched on, filling the room or compartment with ultrasound. The receiver is then deployed on the other side of the structure to scan for leaks. 

When no leak is present, the ultrasound is reflected or absorbed by the structure and so no ultrasound is detected by the receiver. When the receiver wand is pointed towards a leak, ultrasound is detected as it is able to propagate through the leak path. The reflection and diffraction of the sound wave as it passes through the leak path are affected by the size and shape of the leak, meaning information about the size and shape of the leak can be interpreted by the receiver unit. 

Why is Watertightness Important? 

Simply put, watertightness is essential to keep crew, vessels, and cargo safe. Making sure hatches don’t leak is the primary way to ensure confidence against claims for water damage to cargo. Ensuring that cable transits, doors, and bulkheads are as watertight as they should be, means that, in the event of external damage to a vessel, the compartmentalisation of the vessel functions as it should – preventing loss of the ship and saving lives. 

For example, in 2013, the Emma Maersk container ship suffered from the mechanical breakdown of a stern thruster while traversing the Suez Canal. When exposed to water ingress, seven different cable transit seals failed, allowing water to penetrate the engine room and ultimately leading to USD 45 million in damages. Such considerable damages could have been prevented had the seals been tested and replaced. 

Common Applications 

The Portascanner® range has a proven track record in a number of industries and applications: 

  • Shipping/Marine 
  • Defence/Naval 
  • Oil & Gas 
  • Hatch Covers 
  • Watertight & Weathertight Doors 
  • Multiple Cable Transits 

Meets Classification Society Requirements 

The Portascanner is designed to meet Classification Society requirements for watertight integrity type of test equipment. The two most relevant Classification Society requirements are DNVGL-CP-0484 and IACS UR Z17. 

DNVGL-CP-0484 relates to the service supplier (the company conducting the ultrasonic watertight integrity test) and also lists the exact requirements of equipment that needs to be used by such service suppliers for ultrasonic watertight integrity testing to comply with the standards. This is in Page 13 and 14 (Chapter 2). 

Extract from the requirements as below, and the Portascanner complies with all these: 

  • Transmitter shall provide a uniform open hatch value (OHV) over the tested area 
  • OHV shall be adjustable to a stable value allowing maximum sensitivity without false side effects 
  • The receiver shall be provided with an audible signal and a visual readout, calibrated in decibel 
  • Biannual re-calibration tests shall be carried out by laboratories authorised by the manufacturer 
  • Fail/pass criterion to be applied in tightness testing: 
  • 0 dB hatch cover is leak tight 
  • 1 dB to 10% OHV shall mean that the hatch cover is considered weathertight 
  • Above 10% OHV shall mean the hatch cover is considered not to be weathertight 

 

Regulation Compliance 

There are multiple regulations pertaining to watertight/weathertight integrity inspections which are made easier with Portascanner: 

SOLAS Reg II-1/11.1 

“Where a hose test is not practicable… [it may be replaced by] an ultrasonic leak test or an equivalent test. In any case a thorough inspection of the watertight bulkheads shall be carried out.” 

IMO SOLAS Reg II-1/21.3 

“The watertight doors and all mechanisms and indicators connected therewith shall be periodically inspected at sea at least once a week.” 

IMO SOLAS Reg II-1/13-1.1 

“Where penetrations of watertight bulkheads and internal decks are necessary for access, piping, ventilation, electrical cables, etc., arrangements are to be made to maintain the watertight integrity.” 

IACS Rules – Requirements for Ultrasonic Watertight Integrity Service Providers 

“2. Firms engaged in tightness testing of closing appliances such as hatches, doors etc. with ultrasonic equipment.” 

Additional leak sites can be generated within a vessel due to dynamic movement at sea. The severity of structural movement is amplified within a vessel by a constantly changing environment and is affected by varying sea, wind, load states, cargo types, and dynamic stresses. There is a great deal of bending and deformation that naturally occurs in ships during travel which can lead to seal failure. Therefore, regular watertight integrity tests are essential to guarantee safety. 

The Portascanner® WATERTIGHT TOUCH is designed to be the first instrument capable of calculating the flowrate of water through a structure, even when the structure is dry and unpressurised. Therefore, individual flowrates through leaks can be determined, as well as total flowrates into a compartment, with the Portascanner® WATERTIGHT TOUCH. 

Our leak detection systems are active systems, meaning there is a generator, consisting of ultrasonic transmitters, and a receiver wand, which is fundamentally an ultrasonic sensor. This means that it cannot typically be used for applications such as pressurised pipes and partial electrical discharges.  

These applications use passive systems, which detect the ultrasound generated by the leak or electrical discharge itself. The Portascanner® range is designed to monitor airtight and watertight integrity, and to do so without the need to pressurise the room or compartment.  

We usually recommend placing the generator as far from your test structure as possible. whilst maintaining sufficient readings, particularly when you want to quantify leak sites. This is because, due to the diffusion of sound as it travels through air, at greater distances we have more consistent readings across the entire structure. 

However, if space is an issue and you cannot avoid placing the generator close to the structure, the Portascanner® WATERTIGHT TOUCH has both a variable output power on the generator, as well as a variable gain setting on the receiver.  

The Portascanner® WATERTIGHT is designed to assess the condition of a rubber seal or hatch combing quickly and easily. It works on both pontoon type hatch covers and side rolling hatch covers. The receiver wand, with or without an extension attachment, may be traced around the outside of a hatch cover seal and leaks will be picked up visually and audibly through the use of the headphones provided. 

The Portascanner® range is essential for ensuring that MCTs and pipe penetration seals are functioning as claimed. As long as both sides of an MCT are accessible to the operator, it may be tested with either the Portascanner® WATERTIGHT or Portascanner® WATERTIGHT TOUCH. 

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