Tanques Admosfericos- Trainig, Diapositivas de Ingeniería Metalúrgica

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PETROLEUM STORAGE TANKS

Basic Training

PETROLEUM STORAGE TANKS - Basic Training

What we'll be covering

The design of the tank. Which tank , which product. The structure & assembly of the tank. Tank inspection Measurement

Goals for Today

To identify tank type & tank equipments To know the limitation of tank Calculation of tank volume Safe tank operation

STORAGE TANKS- Basic Training 1.0 Background Tanks have been around since the beginning of hydrocarbon

production. Tanks vary considerably, in the type and size based on

the type of products to be stored and the volume involved.

The failure of a tank can have several undesirable effects such as endangering personnel, affecting the environment and interrupting the Operator’s business. Companies therefore, require a consistent approach for assessing tank integrity and maintaining compliance with industry and regulatory standards, (that is community requirements). Such an approach must;

• (^) Ensure tanks are not leaking and will not leak before next inspection
• (^) Reduce the potential for releases
• (^) Maintain tanks in safe operating conditions, and
• (^) Make repairs and determine when replacement is necessary****.

PETROLEUM STORAGE TANKS Basic Training

TANK

The primary function of a storage tank is to store liquid substance. This liquid substance may be: a) Feedstock b) Finished products prior to shipping out to customers (Unit 75) c) and Unfinished petroleum components awaiting for further

**_- processing (intermediate )

• blending_** While in the storage tanks, these products may settle out undesirable substances such as; a) Water b) Emulsions c) Dirt etc. This undesirable substances can then be removed through draw-off devices. Products may also be mixed, blended and treated in storage tanks effectively, using the large capacity available in these tanks.

TANK

For safe storage of petroleum products, we have to consider the product

properties such as volatility (RVP, pour point, flash point and others

before we start designing and constructing the tank.

Floating roof tank Cone Roof Tank Dome Roof Tank Internal Floating Roof Tank

STORAGE TANKS – Basic Training 2.0 The design of the tank Standard vertical tanks are available in several types, which differ in vapor-saving efficiency and in cost. 2.1 Vertical tanks 2.1.1 Open top tanks This type of tank has no roof and shall be used for storing city water, fire water and cooling water (All water tanks in PPMSB are with roofs). 2.1.2 Fixed roof tanks These types of tanks can be divided into:

• Cone roof
• Dome roof Each type can be further subdivided into non-pressure and low- pressure fixed roof tanks.

STORAGE TANKS – Basic Training 2.1.3 Fixed roof tanks with floating covers (internal floating roof tanks) In a fixed roof tank a floating cover can be installed to give a further reduction of vapor losses. These tanks are fitted with breather vents either at the top course of the shell plate or on the roof edge. Typical feedstock/ products stored are: DPK (Kerosene, Jet A1) 2.1.4 Floating roof tank This type of tanks are designed to work at atmospheric pressure. The diameter of a floating roof tanks shall at least be equal to its height to enable the use of a normal rolling ladder for access to the roof. Typical Products stored are: Crude oil, Gasoline and Gasoline components, Solvents…… 2.1.5 Bullets The very volatility & high vapor pressure product such as Isopentane, LPG & Butane will be store in a vessel that will withstand product pressure and prevent any product vaporization. Due to high volatility & high vapor pressure the vessels are Mounded underground to prevent thermal radiation in case of any fire nearby.

STORAGE TANKS – Basic Training Internal Floating Roof Tank

STORAGE TANKS – Basic Training Floating Roof Tank

STORAGE TANKS – Basic Training

STORAGE TANKS – Basic Training

2.3 Stability

For calculations of tank stability in strong winds the following

need to be done:

a) the velocities given in the local regulations should

be used;

b) if no local regulations exist, local experience should

be considered.

Unstable tanks shall be provided with anchor bolts and concrete foundation rings. Uplifting is caused by the internal vapor pressure acting against the underside of the roof, in conjunction with wind load. A stability calculation shall be made to determine the number

of anchors required.

STORAGE TANKS – Basic Training 2.4 Tank Foundation 2.4.1 Checking of foundation Surface, subsurface and climatic conditions vary from place to place, so it is not practical to establish design data to cover all situations. The allowable soil loading and exact type of subsurface construction to be used must be decided for each individual case after careful consideration. Some of the many conditions that require special engineering consideration are as follows: **_> site on hillsides – undisturbed/ land filled

sites at swampy or filled ground sites underlain by soils, such as organic clays that will settle over long period and can cause lateral ground stability problem site adjacent to water courses or deep excavation site exposed to flood water site in regions of high seismicity_**

STORAGE TANKS – Basic Training 2.4 Tank Foundation

2.4.2 Typical Foundation Types

2.4.2.2 Earth foundations with a concrete ringwall large tanks, with heavy or tall shell and/or self-supported roofs impose a substantial load on the foundation under the shell. When there is some doubt whether a foundation will be able to carry the load directly, a concrete ringwall foundation should be used. _Advantages of concrete ringwall are:

It provides better distribution of the concentrated load of the shell to produce a more uniform soil loading under the tank It provides a level, solid starting plane for concentration of the shell It is capable of preserving its contour during construction It retains the fill under the tank bottom and prevents loss of material as a result of erosion It minimizes moisture under the tank_

STORAGE TANKS – Basic Training 2.4 Tank Foundation

2.4.2 Typical Foundation Types

2.4.2.2 Earth foundations with a concrete ringwall Other design requirements are:

The ringwall shall not be less than 300 mm (12 in) thick Depth of ringwall depends on the local conditions 2.4.2.3 Earth foundations with a crushed stone and gravel ringwall A crushed stone or gavel ringwall will provide adequate support for high load imposed by the shell. Advantages are: It provides better distribution of the concentrated load of the shell to produce a more uniform soil loading under the tank It provides a means of leveling the tank grade, and it is capable of preserving its contour during construction It retains the fill under the tank bottom and prevents loss of material as a result of erosion it can more smoothly accommodate differential settlement because of its flexibility