Tank Maintenance and Renovation - tankref.dk. Force - Tank... · Tank Maintenance and Renovation . Presenters Andy King/Bo Svagin . Presenters Principle Engineer Technical Integrity

Tank Maintenance and Renovation Statoil Refining Denmark – Kalundborg Refinery

2017-11--03 Classification: Open

Denmark

Classification: Open

Kalundborg København

Hedehusene

2017-11-03 Classification: Open

Statoil Kalundborg seen from the air

Process area

Jetty

Tankfarm

Statoil Kalundborg – Tankfarm

• The refinery tank farm consists of 80 atmospheric storage tanks in various sizes from 200m3 up to 80,000m3. The first tanks are from 1961 and are designed in accordance to API 12C, new tanks are design in accordance to API 650, TR3011 and TR1827 (internal Statoil requirements for tanks and civils).

• As supplement to the refinery's own tanks, we operate 6 further tanks of 55,000m3 each.

• Atmospheric storage tanks at the refinery are operated for 15 years, if the tank bottom is not coated, and for 20 years if the tank bottom is coated.

• We are working towards having the scope of work ready 3 years before a tank is taken out of service for maintenance. Time out of service depends on the tank size and scope of work, hereafter the tank is ready for a new period of 15 to 20 years of service.

2017-11-03 4 Classification: Open


Maintenance and Renovation Process

Starting point – Tank Strategy Document

• A Tank Strategy Document was created in 2010.

• The Strategy Document contains input from all relevant disciplines that may have a role to play in the final renovation scope of work.

− Mechanical – shell, roof (cone or floating), tank bottom and annular plates and appurtenances.

− Piping, number and condition of supports, replacement and / or refurbishment of valves Previously seen corrosion problems where saddle supports have been fixed over large pipes

− Civils, Condition of bund wall, measurement of dyke settlements*, penetrations and seals , condition of drainage gutters and collection wells.

− Electrical, existing electrical circuits and cable routing, servicing of motors and actuators, evaluation of lighting

− Instrumentation, Level radar, multi point temperature chain, VHLA Mowbrey switch, new XHLA radar system.

− Safety Systems, Fire Detection, Gas Detection, Fire Fighting Equipment

* To ensure 110% secondary containment capacity


Starting point – Tank Strategy Document

• Points that are always implemented under a 15 or 20 year service renovation.

− New drainage sump in tank bottom.

− Removal of double tank bottom or double anular plate “post box” if present

− Removal of samples from the tank bottom to investigate underside corrosion.

− Renovation of tank foundation shoulder. – If complete new tank bottom then new tank foundation and HDPE leak detection membrane

− External painting of top and bottom shell courses (other repairs can be made in service if necessary).

− For non-heated tanks the tank bottom and first 1m of the shell is coated internally

− Implementation of SIL 2 overfill protection for class I (crude oil and gasoline) products.

− Implementation of rim seal fire detection for floating roof tanks.

− Renovation of bund to 110% capacity of largest tank or 100% of largest tank capacity + 15cm.


Mechanical Evaluation

• Define tank history and construction type

• Review previous inspection reports

− Thickness measurements, inspection / scanning reports for tank bottom and annular plates

• Specify required new NDT inspections

− Visible corrosion, deformation, painting condition, nozzles condition.

− Thickness measurements strength calculations for residual life / need for wind girder.

• Use highest of average corrosion rate over tank life against corrosion rate over last 20 years to estimate condition after next 20 year service interval.

• Use of internal and external coatings can justify a reduced corrosion rate.

− Floating roofs – History for centre deck and pontoons

• Other Considerations

− Condition of rolling ladders, stairs, platforms,

− Wind girder mechanical condition, painting, drainage to avoid standing water at shell / girder weld.

− Insulated tanks – condition of insulation and jacketing, especially at penetrations – risk of CUI


TK-1301, Ø 52.3m floating pontoon roof Example of major renovation and problems with older tanks




Scope of mechanical work • Installation of 2 extra

shell courses to increase capacity



Scope of mechanical work • Original tank bottom

removed • Extensive underside

corrosion • Poor civils preparation

at original tank construction

• Tank lacked anular plates. (Protuding tank bottom plates!)



Scope of mechanical work • Existing pontoon roof

scrapped



Scope of mechanical work • New double deck roof

When it goes wrong – Paulsboro New Jersey – February 2012


Leak of approx. 23.000m3 from a 45.000m3 tank Investigation subsequently pointed to underside corrosion of the anular plates in an area that is difficult to measure Essentially failure mechanism was impossible to detect at that time.

Can it happen to us? • Shell – Tank shoulder and anular

plates

• We discovered thinning and corrosion of the anular plate of a naphtha tank 2 years ago.

• This resulted in the tank being taken out of service for 2-3 months unplanned maintenance to renew the anular plate.

• The problem arose because of settlement on the old asphalt tank shoulder.

• Our traditional solution has been asphalt shoulder with concrete under potential leakage points such as mixers. We now use a complete concrete shoulder.


Shell

Tank bottom

Annular Plate lifts because of . settlement

Foundation

TK - 1338 problem

Asphalt shoulder

Water ingress

Tank Maintenance and Renovation

Presenters Andy King/Bo Svagin Presenters Principle Engineer Technical Integrity E-mail address [email protected] [email protected] Tel: +45 59 57 27 03 / +45 59 57 37 42 www.statoil.com


Documents

Tank Maintenance and Renovation - tankref.dk. Force - Tank... · Tank Maintenance and Renovation . Presenters Andy King/Bo Svagin . Presenters Principle Engineer Technical Integrity