K Controls has used its expertise in sub-sea ingress protection and hazardous area approvals to develop 007-100 valve position monitors that will be used in a new floating, production, storage and offloading vessel (FPSO) being built for BP by Hyundai Heavy Industries in Korea.
The new FPSO will replace the existing Schiehallion FPSO that has been moored in 400m of water, 281km (175 miles) west of the Shetland Isles in the UK, producing oil from the Schiehallion and Loyal fields since 1998.
The reservoir sits 2000m below the seabed, covering an area of approximately 194sq km (75sq miles.) As a result of further exploration and technological developments during the past 20 years, recoverable reserves are now known to be more than double the original estimates. The Quad 204 project will also include an extension of the existing subsea system with a number of new wells. The FPSO and its subsea structures will be producing by 2017.
A total of 147 valve position monitors have been supplied for use on hydraulically actuated ball and butterfly valves. The valves will be used in the sea water ballast tanks that are used for vessel stabilisation. K Controls worked closely with the engineers at the Offshore Design & Engineering Division of Hyundai Heavy Industries in Korea, in order to arrive at an exact specification.
The majority of the position monitors contain end of travel reed proximity switches and some provide a 4-20mA with HART signal to monitor the position of modulating control valves or the opening and closing characteristics of critical isolating valves. Klearvision visual indicators were specified for certain applications. The 007-100 enclosures have been investment cast from a high-alloy austenitic stainless steel developed for use in seawater and other aggressive chloride-bearing media. They have been independently tested by SGS Baseefa to IP68, for submersion at a depth of 30 metres.
When not submerged, the position monitors could be in an area where hazardous gasses are present. They are therefore ATEX and IECEx intrinsically safe certified II 2 G Ex ia IIC T6. All the units have been supplied with multi pin connectors and the associated cable sets that meet the exacting standards required for both subsea and shipboard use. Each cable set has been cut to a predefined length between 19 and 166 metres in order to facilitate installation. Mounting kits for the actuators were supplied in Super Duplex stainless steel.
These products are also available with INMETRO hazardous area certification for similar projects in Brazil.
K Controls sub-sea
valve position monitors have been specified for use Aquamarine Power’s Oyster
wave energy device that captures energy in near shore waves and converts it
into clean sustainable electricity. The valves will control the flow of the
high pressure water that is generated by the movement of the wave flap and
associated hydraulic pistons and then moved onshore, via a pipeline, to drive a
conventional hydro-electric turbine. Low pressure pipes will transport the
water back from the hydroelectric power station to the wave energy device.
It meets all of
the clients requirements and can be calibrated remotely using the HART®
protocol without diver intervention.
The field proven
sub-sea position monitor has been used on applications that include:
the position of hydraulically actuated valves that flood the jackets on
the legs of oil rigs during satellite guided positioning.
the position of failsafe valves on conventional tanker buoy mooring
the position of valves in the ballast tanks of semi-submersible oil rigs.
devices are important because the central aim of UK Government energy policy is
to establish a supply of energy that is diverse, sustainable, secure and
competitively priced. Ocean waves represent our planet's last untapped natural
renewable energy resource. The energy contained within waves has the
potential to produce up to 80,000TWh of electricity per year - sufficient to
meet global energy demand five times over. Wave energy is, by its nature, a
clean energy resource. Aside from the energy expended in manufacture and
installation of wave energy devices, it produces no carbon emissions. In
the future, subsea pipelines will connect multiple wave energy devices to a
single onshore plant creating wave farms of several hundred connected devices
generating hundreds of megawatts of electricity. The devices sit largely
underwater so there is minimal visual impact.
There is also a
link between wave energy and desalination - the process of removing salt from
water to produce freshwater. Energy fuelled by diesel generators is
currently used to pump high pressure saltwater over special membranes to
produce freshwater. A wave energy device offers a cleaner, more cost-effective
solution. It could be configured to produce high pressure saltwater direct to a
desalination plant, without the need for any fossil fuels.
Once you have selected an actuator for use in sub-arctic climates it is worth remembering that K Controls manufactures complementary Position Monitors in coated aluminium or stainless steel. There are standard and Exd versions for use down to -60 degrees C and Exi versions for use down to -50 degrees C.