GAMMA FLOODED MEMBER DETECTION (FMD)

Flooded Member Detection by gamma source allows for offshore platform members to be inspected for flooding as a result of cracking, damage, corrosion or weld defect, without the need for high levels of cleaning required by other methodologies. As such, a more tailored inspection plan can be prepared for more detailed investigation as well as other inspection tasks and techniques.

Flooded Member Detection is designed to indicate whether through-thickness cracking has occurred to a structure, resulting in member flooding, without the need for the member to be cleaned down to bare metal. This allows detailed crack inspection to be carried out on a limited number of high-risk members, saving both time and cost.

The use of radioactive sources for the inspection for flooded members on offshore steel structures is a well-proven technique. The PMAC Gamma FMD system has operated with radioactive sources offshore for more than 25 years and was developed from this extensive experience to address the specific needs of repair and maintenance programs in conjunction with subsea inspection requirements.

The PMAC ROV-mounted FMD system uses a small radioactive source to cover member sizes from 150mm up to 3m diameter. A radioactive source and robust detector unit are mounted on opposite forks of a variable yoke positioned across the diameter of the member under inspection. The ROV Mounting frame can be configured to operate at any angle from horizontal to vertical to suit measurements on horizontal, diagonal or vertical members. Our proprietary software package analyses and records the data quickly and efficiently allowing for production of a report within hours of completing a work scope and single member results within minutes.

The ROV-mounted FMD system operates on the principle that a collimated beam of radiation is transmitted through the member and received by the detector at the other side. The strength of the received beam is compared with computer predictions for a dry, flooded or partially flooded member.

The advantages of the system include, but are not restricted to, the following:-

Survey is fast and can exceed 30 components per hour with the resulting assessment instant and clear.
Prior removal of marine growth and cleaning is unnecessary saving time and cost
May be safely and effectively deployed by ROV
A proven system with an impressive track record since 1991
Configured for survey of horizontal or vertical components
Detection of water ingress to structural steel jacket members.
Pipeline inspection providing flooded or dry status and the location of 'pigs' or other blockage.
Location and monitoring of gamma emitting equipment or materials 'lost' in a subsea environment.
Detection and level measurement of fluids in small vessels and pipes in a subsea environment.

Our FMD technicians hold Radiation Protection Supervisor qualifications as well as other regulatory requirements for the region of operation to assure safety. FMD Technicians may also hold other qualifications such as CP or CSWIP, enabling them to fulfill multiple roles on a vessel, saving on time, bed space and ultimately, cost.

Download the brochure below to learn more about our Gamma Flooded Member Detection (FMD)