A floating production storage and offloading unit (FPSO) is a vessel used in offshore production for the production, storage, refining, and loading of extracted oil or natural gas. Such systems have become a primary method in many offshore production regions worldwide. As with other applications in flammable environments, electrical control of certain processes requires explosion-proof solutions to minimize risks to people, the environment, and equipment.
Task
A well-known American control system manufacturer wanted to equip an FPSO vessel owned by one of its end customers with a comprehensive electrical solution. To achieve this, the control system manufacturer required various enclosures certified to ATEX and IECEx standards for Zone 1 and temperature class T4 so that the solution could be equipped with remote I/O systems. Cabinet sizes ranged from 1000 × 1500 × 450 mm to 800 × 2100 × 1000 mm (W/D/L). All enclosures were required to comply with Ex pyb protection type. Additionally, the control system manufacturer required an external control function to ensure that the remote I/O systems could continue to operate safely even if the purge and pressurization control unit was disabled.
Solution: Pepperl+Fuchs Series 6500 purge and depressurization system controls and monitors onboard processes
To meet these requirements, Pepperl+Fuchs engineers decided to use the 6500 Series Purge and Pressurization System.
This system consists of a control unit, a safety valve, and a manifold valve, which form the basis for the required explosion-proof enclosure solution. The enclosures themselves are constructed entirely of SS316L stainless steel, making them suitable for use in the harsh marine environments aboard an FPSO vessel.
Special vibration dampers installed between the base and the hull protect the hull and electrical components from possible mechanical damage caused by engine vibration and marine conditions.
To provide the necessary external control of the purge and pressurization system, a combination of relays and contactors certified for use in Zone 1 had to be installed in the circuit. In the event of a problem on the FPSO, the remote I/O system can now override the purge and depressurization system control unit via an output signal and continue safe operation, as air continues to flow through the needle valve and pressure is maintained.
This feature also simplifies control unit maintenance, as it eliminates the need to stop the entire process. Additional contactors and relays ensure automatic switching between the two power sources in the event of a failure of one.
With this sophisticated purging and pressurization solution from Pepperl+Fuchs, the customer can safely and efficiently manage and control processes on its FPSO in the Indian Ocean.
Benefits of the solution
The end customer received durable hull solutions suitable for use in ATEX and IECEx zones and designed to withstand the harsh marine conditions on board the FPSO vessel.
The previously expensive and time-consuming process of coordinating with various suppliers of individual components and applying for system certification was replaced by a one-stop shop at Pepperl+Fuchs: all services, such as design, construction, production and certification, were carried out under one roof by specialists in explosion protection for electrical equipment.
---
This article is based on materials from our partner Pepperl+Fuchs.
Power Technology Solutions is the official distributor in the Republic of Kazakhstan.
Pepperl+Fuchs, a leader in purging technology, has over 25 years of experience producing innovative and certified solutions that are remarkably easy to use and can handle virtually any of these challenges with ease.