API 650 Storage Tanks

TECHNICAL SPECIFICATION API 650 STORAGE TANKS

DATE: 01 MAY 2003

ENGINEERING SERVICES BY KBR TECHNICAL SERVICES, INC.

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TABLE OF CONTENTS Section 1. 1.1 1.2 1.3 1.4 1.5 1.6 2. 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3. 3.1 3.2 4. 4.1 4.2 5. 5.1 5.2 6. 6.1 6.2 6.3 6.4 6.5 7. 7.1 7.2 7.3 8. 9. 9.1 9.2 9.3 9.4 9.5 10. 10.1 10.2 10.3 10.4

Title Page No. GENERAL ......................................................................................................................................2 Scope..............................................................................................................................................2 Units of Measurement.................................................................................................................... 2 KBR Documents, Codes, and Industry Standards ........................................................................ 2 Design Drawings and Data ............................................................................................................ 3 Technical Data to be Furnished with Tank Manufacturer's Proposal ............................................ 3 Documentation and Records ......................................................................................................... 4 DESIGN ......................................................................................................................................... 4 General .......................................................................................................................................... 4 Tank Shells .................................................................................................................................... 4 Tank Bottoms................................................................................................................................. 5 Tank Roofs..................................................................................................................................... 5 Corrosion Allowances .................................................................................................................... 6 Nozzles and Connections .............................................................................................................. 6 Anchor Bolting................................................................................................................................ 7 Structural Steel .............................................................................................................................. 7 Tank Insulation............................................................................................................................... 8 CONE ROOF/DOME ROOF TANKS WITHOUT INTERNAL FLOATING ROOFS...................... 8 General .......................................................................................................................................... 8 Appurtenances and Accessories ................................................................................................... 8 EXTERNAL FLOATING ROOF TANKS ....................................................................................... 9 General .......................................................................................................................................... 9 Appurtenances and Accessories ................................................................................................... 9 COVERED FLOATING ROOF TANKS (INTERNAL FLOATING ROOFS).................................10 General .........................................................................................................................................10 Appurtenances and Accessories ..................................................................................................10 MATERIAL ...................................................................................................................................11 General .........................................................................................................................................11 Filler Materials...............................................................................................................................11 Supplementary Materials ..............................................................................................................12 Gaskets.........................................................................................................................................12 Bolting ...........................................................................................................................................12 FABRICATION .............................................................................................................................12 General .........................................................................................................................................12 Welding .........................................................................................................................................12 Tolerances ....................................................................................................................................12 ADDITIONAL REQUIREMENTS FOR EPOXY & RUBBER LINED TANKS..............................13 INSPECTION, REJECTION, EXAMINATION, REPAIRS, AND TESTING .................................14 Inspection......................................................................................................................................14 Rejection .......................................................................................................................................14 Examination ..................................................................................................................................14 Repairs..........................................................................................................................................14 Testing ..........................................................................................................................................14 MARKING, PAINTING, AND SHIPPING .....................................................................................15 Marking .........................................................................................................................................15 Painting .........................................................................................................................................15 Preparation for Shipment..............................................................................................................15 Shipping ........................................................................................................................................15


DATE: 01 MAY 2003



1. GENERAL 1.1 Scope This specification defines mandatory technical requirements for the design, materials, fabrication, shipping, erection, inspecting, and testing of API 650 Tanks. 1.2 Units of Measurement U.S. Customary units or metric units of measurement shall be used by the manufacturer for drawings and calculations consistent with the units of measurement shown on the KBR tank drawings and/or data sheets. 1.3 KBR Documents, Codes, and Industry Standards The following documents are referenced herein and form part of the Order. Additional KBR documents, when applicable, will be listed on the Requisition. The issue of KBR documents shall be as specified in the Requisition. Current editions of the industry standards including all mandatory addenda in effect at the time of the order shall apply unless otherwise indicated. KBR DOCUMENTS 4-7TS, "General Welding Requirements" MF40-1PS, "General Purchasing Requirements for API Storage Tanks" SDR-1MDMF, "Supplier Drawing and Data Requirements for Pressure Vessels API Tanks, Vessel Trays, and Internals” SDR-2MF, “Supplier Data Requirements for API Tanks” AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) ASME B1.20.1, "Pipe Threads, General Purpose (Inch)" ASME B16.5, "Pipe Flanges and Flanged Fittings NPS 1/2 Through NPS 24" ASME B16.11, "Forged Fittings, Socket-Welding and Threaded" ASME B16.47, "Large Diameter Steel Flanges NPS 26 Through NPS 60" AMERICAN PETROLEUM INSTITUTE (API) API 650, "Welded Steel Tanks for Oil Storage" API 2000, "Venting Atmospheric and Low-Pressure Storage Tanks Nonrefrigerated and Refrigerated" API MPMS Ch2.2A, "Measurement and Calibration of Upright Cylindrical Tanks by the Manual Strapping Method" AMERICAN INSTITUTE OF STEEL CONSTRUCTION (AISC) AISC, "Steel Construction Manual" CODE OF FEDERAL REGULATIONS (CFR) 29CFR, Part 1910, Subpart D, "Walking-Working Surfaces" 40CFR, Part 60, Subpart Kb, "Standards of Performance for Storage Vessels for Petroleum Liquids" NATIONAL ASSOCIATION OF CORROSION ENGINEERS (NACE) NACE RP0178, "Fabrication Details, Surface Finish Requirements, and Proper Design Considerations for Tanks and Vessels to be Lined for Immersion Service" NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) NFPA 30, "Flammable and Combustible Liquids Code" RUBBER MANUFACTURER'S ASSOCIATION (RMA) Technical Bulletin Nos. 1 & 2, "Protective Linings"


DATE: 01 MAY 2003

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1.4 Design Drawings and Data 1.4.1 The Purchaser will furnish the manufacturer with tank drawings or data sheets specifying the tank configuration, dimensions, capacity, material requirements, design pressures and temperatures, product specific gravity, corrosion allowance, insulation and painting requirements, wind, earthquake, and snow load design criteria, certain construction details and engineering data as required by the manufacturer to mechanically design and construct the tank. 1.4.2 When the Purchaser requests the manufacturer to furnish a tank conforming to the manufacturer's proprietary design, the materials of construction and other construction details shall be selected by the manufacturer based on the design conditions specified by the Purchaser. 1.4.3 Acceptance of Supplier drawings and data with details which deviate from those shown on Purchaser's drawings, data sheets or specifications does not constitute acceptance of the deviations. Manufacturer shall obtain separate written approval from Purchaser for all such deviations, prior to submission of drawings and data, for Purchaser's review and acceptance. 1.5 Technical Data to be Furnished with Tank Manufacturer's Proposal The following technical information shall be included as a part of the proposal: a.

The basis used for tank design (basic API and/or applicable appendix).

b.

The proposed plate thickness and material specifications for the roof, shell, bottom, annular plates, and compression rings.

c.

The proposed slope of cone roofs or radius of dome/umbrella roof and type of welded joints.

d.

Size and quantity of anchor bolts or straps, if required.

e.

The proposed materials for internals, appurtenances and accessories for epoxy or rubber lined tanks.

f.

Foundation design loads for Purchaser's use in designing tank foundations. The required loads are as follows: LOAD 1. 2. 3. 4. 5. 6. 7. 8.

shell dead load roof dead load (applied to shell) insulation dead load (applied to shell) roof partial vacuum load roof live load (applied to shell) roof support column(s) load wind moment and shear at tank bottom earthquake moment and shear at tank bottom with tank full of liquid. 9. product load and design pressure on tank bottom 10. test load and test pressure on tank bottom 11. tank bottom insulation load 12. maximum uplift on each anchor bolt or strap

UNITS lb/ft (N/m) of circumference lb/ft (N/m) of circumference lb/ft (N/m) of circumference lb/ft (N/m) of circumference lb/ft (N/m) of circumference lb (N) ft·lb (N·m) and lb (N) ft·lb (N·m) and lb (N) lb/ft2 (Pa) lb/ft2 (Pa) lb/ft2 (Pa) lb (N)

The earthquake moments transmitted to the Purchaser must include both the overturning moment at the bottom of the tank shell and the overturning moment applied to the tank foundation. The moment applied to the tank foundation shall be calculated in accordance with the paper titled "BASIS OF SEISMIC DESIGN PROVISION FOR WELDED STEEL OIL STORAGE TANKS" by R.S. Wozniak and W.W. Mitchell, published in API Proceedings 1978, 43rd midyear meeting.


DATE: 01 MAY 2003



g.

Calculated liquid slosh heights (under design earthquake conditions)

h.

For external and covered floating roof tanks, the maximum liquid level (maximum level at which the roof can be safely floated) and the minimum level at which the roof will float without resting on its support legs. (This is necessary to confirm that the tank size assumed by the Purchaser and net capacity are adequate.) Net capacity is the volume between the maximum liquid level and the minimum liquid level.

i.

Quantity to be supplied and catalog information on proposed level gage, level alarm and transmitters, pressure and vacuum relief valves, emergency vent, other accessories, etc.

j.

Annular roof to shell seal details and roof penetration seal details for floating roofs.

1.6 Documentation and Records The Seller shall submit drawings and data of the type and quantity specified on the Supplier Drawings and Data Requirements form (SDR-2MF). Instructions and requirements for Supplier drawings and data are contained in KBR Purchasing Standard SDR-1MDMF. 2. DESIGN 2.1 General 2.1.1 Manufacturer shall check the acceptability of loads on shell openings in accordance with API 650, Appendix P, when requested by Purchaser. 2.1.2 Normal and emergency venting shall be in accordance with API 2000. For un-anchored tanks, the vent setting for emergency venting shall not be higher than the smaller of P or Pmax as determined per formula given in API 650 Paragraphs F.4.1 and F.4.2. Area provided by gauge hatch opening may be considered for emergency venting capacity when suitable gauge hatch is provided with self-closing cover. 2.1.3 Tanks constructed of stainless steel shall comply with API 650, Appendix S, with shell joint efficiency not less than 0.85. 2.2 Tank Shells 2.2.1 Tank shell thickness shall be calculated by the “one-foot” method in accordance with API 650, Paragraph 3.6.3. Manufacturers may additionally propose a clearly-labeled alternate shell thickness calculated by the “variable design point” method in accordance with API 650, Paragraph 3.6.4, if a more economical design is possible. Tank shell design based on Appendix A of API 650 may be used when the joint efficiency is considered as 0.85 and the thickness including corrosion allowance is not more than 1/2 inch (12.7 mm). 2.2.2 Shell seams shall be located to clear openings to the maximum extent possible in accordance with API 650 Paragraph 3.7.3.1 so as to avoid postweld heat treatment. 2.2.3 The top angle shall be attached to the shell by a full penetration buttweld. The outstanding leg of the top angle shall extend outside the tank unless otherwise specified on drawings or data sheets. 2.2.4 When roof to shell junction is not frangible in accordance with API 650 Paragraphs 3.10.2.5.2 and 3.10.2.5.3, the tank fabricator shall provide emergency venting devices in accordance with API 2000. 2.2.5 Tank shells shall be designed to resist buckling from the design wind velocity without intermediate wind girders unless otherwise specified by the Purchaser.


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2.2.6 Tank shells shall be furnished with 24 inch (610 mm) inside diameter manholes in accordance with Table I. TABLE I - TANK SHELL MANHOLES TANK DIAMETER feet (meters)

NUMBER OF MANHOLES

Over

Through

0

75 (22.9)

1

75 (22.9)

150 (45.7)

2

150 (45.7)

3

2.2.7 The minimum tank shell thickness shall not be less than the greater of: ` a.

0.1 inch (2.5 mm) plus corrosion allowance.

b.

Calculated thickness plus corrosion allowance.

c.

Minimum thickness in accordance with API 650.

2.2.8 When tank is constructed of alloy steel or stainless steel other than those included in API 650, Table S-1 of Appendix S, the allowable stress(es) will be specified on the tank drawings or data sheets. 2.2.9 Un-anchored tanks located in an area subject to flooding shall have the tank foundation elevated sufficiently enough that the flood water level above the tank bottom will not cause uplifting of the tank shell when the tank is empty. 2.3 Tank Bottoms 2.3.1 Bottom plates may be lap-welded with the lap toward the direction of drainage. Buttwelded bottom plates shall be furnished when specified on the tank drawings or data sheets or when tanks are specified to have rubber lining. 2.3.2 When the upper rim of drawoff sump is constructed in accordance with API 650, Figure 3-16, sketch “a1 or a2", the upper rim of the sump shall overlap the tank bottom by a minimum of 1.5 inches (38 mm). Suitable compacted fill material shall be provided to support the sump. For rubber lined tank, detail “a3" of API 650, Figure 3-16 shall be used. 2.3.3 Buttwelded annular bottom plates shall be furnished when required by Paragraph 3.5.1 of API 650 or when tanks are specified to have rubber lining. 2.3.4 Unless otherwise specified on tank drawings or data sheets, tank bottom shall be crowned from its outer periphery to its center at a slope of 1 in 120. Cementitious grout, 1 inch (25 mm) thick, shall be provided under the tank shell when the tank shell rests on a concrete ringwall. 2.4 Tank Roofs 2.4.1 The preferred fixed roof configuration (cone or dome or umbrella) will be specified on the tank drawings or data sheets. When the Purchaser has specified a cone roof, the manufacturer may propose a clearly-labeled alternate dome roof or umbrella roof design if it is more economical. When dome or umbrella roof is specified, the roof radius shall not be more than 1.0 D, where D is the nominal diameter of tank. Unless otherwise specified on tank drawings or data sheets, tank roofs shall be designed for a minimum load of 25 lb/ft2 (1.2 kPa).


DATE: 01 MAY 2003



2.4.2 When tanks are specified to have an internal rubber or epoxy lining, the roof shall be self-supporting or have an external supporting structure. 2.4.3 Roofs plates shall have single lap-welded joints welded on the outside. The lap joints shall be seal-welded on the inside when the roof is specified to have epoxy lining. Buttwelded roof plates shall be furnished when specified on the tank drawings or data sheets or when roof is specified to have rubber lining. 2.4.4 When tanks are located in areas subjected to earthquakes, the roof rafters of a supported roof, made of channel or angle sections, shall be provided with suitable bracing in accordance with Paragraph 3.10.4.5 of API 650. 2.4.5 Roof columns and roof framing for column supported cone roof tanks shall be designed to accommodate, for differential settlement of tank bottom, the increase in column height of 1/4 inch per 3 feet (7 mm per meter) of the column distance from tank shell regardless of whether the tank bottom is flat or sloping. 2.5 Corrosion Allowances 2.5.1 For each surface in contact with product/vapor, the specified corrosion allowance shall be added to the required thickness of all load-carrying components including shell, roof, bottom and roof supports. 2.5.2 One-half the specified corrosion allowance shall be added to each surface of nonload-carrying internal components. 2.5.3 The specified corrosion allowance shall be added to the thicknesses obtained from API 650 Table 3.3 and 3.4 for manway cover, bolting flange, manway neck, and to those obtained from API 650 Table 3-18 for drawoff sump. 2.6 Nozzles and Connections 2.6.1 Flange bolt hole orientation shall be as follows: a.

When the flange is in a horizontal plane, the bolt holes shall straddle the north-south centerlines indicated on the design drawings.

b.

When the flange is in a vertical plane, the bolt holes shall straddle the vertical centerline of the flange.

c.

Bolt hole orientation of flanges not specified above will be shown on the design drawings.

FIGURE 1 - BOLT HOLE ORIENTATION


DATE: 01 MAY 2003



2.6.2 Raised face and flat face flanges shall be furnished with a stock gasket surface finish. 2.6.3 Flanges for external nozzles NPS 24 and smaller shall be in accordance with ASME B16.5 for the rating and type of facing specified. Flanges for external nozzles NPS 26 through NPS 60 shall be in accordance with ASME B16.47, Series B. For sizes over NPS 60, flange dimensions will be shown on the drawings or data sheets. Manway flanges shall be in accordance with API 650, table 3.3. 2.6.4 Each reinforcing pad, or segment if more than one piece is used, shall be provided with one NPS 1/4 NPT threaded hole. Welds in segmented two-piece reinforcing pads on shell and conical roof shall be in the circumferential direction. The outside edge of reinforcing pads shall be ground or otherwise made reasonably smooth before welding to the tank. 2.6.5 Threaded connections shall be Class 6000 couplings. 2.6.6 All threaded connections shall have NPT threads conforming to ASME B1.20.1. 2.7 Anchor Bolting 2.7.1 Anchor bolting shall be designed for uplift due to internal pressure alone for an allowable tensile stress of 15 000 psi (103.4 MPa) on the root area of the thread. Allowable stress may be increased by 33% for wind or earthquake loadings. 2.7.2 For anchored tank, anchor chairs or anchor straps shall be provided and installed on tank shell by Tank manufacturer. Purchaser will arrange for the supply and installation of anchor bolts or installation of anchor straps into the tank foundation. 2.8 Structural Steel 2.8.1 Tanks 20 feet (6.0 m) or less in height shall be furnished with a ladder without a cage. Tanks greater than 20 feet (6.0 m) in height shall be furnished with a spiral stairway. The ladder or spiral stairway may be of the tank manufacturer's standard design in accordance with 29CFR, Part 1910, Subpart D requirements. Spiral stairways on insulated tanks shall be furnished with an inside stringer; the treads shall not be welded directly to the shell. 2.8.2 A landing platform (gauger's platform) shall be furnished at the top of the ladder or spiral stairway. Wing rails extending 6 feet (2.0 m) from the edge of the platform (on two sides along the circumference of the tank) shall be furnished. 2.8.3 Dome roof tanks or cone roof-tanks with roof slope greater than 1:4 shall be furnished with walkways extending from the landing platform to the center of the roof or to the other roof platforms for the maintenance of roof mounted accessories, when shown on the tank drawings. Unless otherwise shown on tank drawings, the walkway may be in the form of anti-skid bars welded to the roof plate with handrails provided on both sides of walkway. 2.8.4 All walkways, stairways, and platforms shall be furnished with handrails on open or exposed sides. 2.8.5 Platforms shall be designed for a uniform live load of 75 lb/ft2 (3.6 kPa). 2.8.6 Unless otherwise specified on tank drawings or data sheets, the platform and stairway flooring shall be galvanized, rectangular, welded grating with 1 inch x 3/16 inch (25 mm x 5 mm) bearing bars on 1 3/16 inch (30 mm) centers and cross bars on 4 inch (100 mm) centers. If checker plate is specified, it shall be 1/4 inch (6 mm) thick.


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2.9 Tank Insulation 2.9.1 When tank is required to be insulated, the thickness and type of insulation or a basis for designing the insulation system will be specified by Purchaser. 2.9.2 The insulation supports for shell and roof insulation shall be provided in accordance with the details shown on the tank drawings. 3. CONE ROOF/DOME ROOF TANKS WITHOUT INTERNAL FLOATING ROOFS 3.1 General 3.1.1 Roofs of unlined tanks (no rubber lining or epoxy coating) may be self-supporting or supported at the option of the tank manufacturer unless otherwise specified on tank drawings or data sheets. 3.1.2 If pipe or other closed structural shapes are used to support roofs, they shall have a vent at the top and a drain at the bottom. 3.1.3 Normal and emergency venting shall be per API 2000. 3.2 Appurtenances and Accessories Cone roof and dome roof tanks shall be furnished with the following: a.

The number of 24 inch (610 mm) inside diameter roof manholes as specified below: TANK DIAMETER feet (meters)

NUMBER OF MANHOLES

Over

Through

0

75 (22.9)

1

75 (22.9)

150 (45.7)

2

150 (45.7)

3

b.

One water drawoff sump with internal piping and shell nozzle.

c.

8 inch (200 mm) diameter gauge hatch with self-closing non-sparking cover.

d.

One ground-reading automatic level gauge with digital readout, float, and float guide wire assembly or when specified on tank drawings or data sheets, a level indicator with indicator board, float and guide wire assembly, including all necessary nozzles, mounting brackets, supports, guides, and hardware required and installed for a complete assembly.

e.

A scaffold cable support for tanks over 18 feet (5.5 m) high.

f.

Four grounding (earthing) lugs.

g.

Free vents with stainless steel bug screen for atmospheric tanks or, when specified, pressure vacuum vent valve(s) equipped with car seal open block valves(s) on the tank side, for blanketed or low pressure tanks.

h.

Foam chambers and foam piping, when specified.

i.

Tank heaters, internal piping, and shell nozzles, when specified, including all necessary nozzles, mounting brackets, supports, guides, and hardware required and installed for a complete assembly.


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j.

Shell nozzles and supports for side entering mixers, when specified.

k.

Emergency vent when required by Paragraph 2.1.2.

l.

Level alarms and level transmitters when specified, including all necessary nozzles, mounting brackets, supports, guides, and hardware required and installed for a complete assembly.

4. EXTERNAL FLOATING ROOF TANKS 4.1 General 4.1.1 The roof shall be either a pontoon type or double deck type. The top edge of all bulkhead plates shall be welded for liquid tightness. Roof shall be contact type to eliminate the presence of any air-vapor mixture under the deck. 4.1.2 Roof seal material shall be suitable for the stored products (e.g., aromatics). 4.1.3 Wind girders shall be furnished with drain holes. The wind girders shall be checked for drainage during tank testing. When the tank manufacturer has the tank filled as required with the testing fluid, he shall then run water into the wind girder with a hose. Within 15 minutes, the girder shall be checked to see if all the water has drained through the regularly supplied drain holes. If water stands over 1/16 inch (1.5 mm) deep on any portion of the wind girder, an additional drainage hole shall be drilled in the lowest spot in that area so that complete drainage will result. 4.2 Appurtenances and Accessories External floating roof tanks shall be furnished with the following: a.

The number of through-deck manholes for access to the inside of the tank as specified below: TANK DIAMETER feet (meters) Over

Through

0

150 (45.7)

150 (45.7)

NUMBER OF THROUGH-DECK MANHOLES 2 3

One manhole to be the minimum size necessary to service (remove) the roof drain assembly, but not less than 24 inch. The remainder shall be 24 inch size. b.


c.

One 8 inch (200 mm) diameter gauge hatch with self-closing non-sparking cover. Hatch cover shall be capable of being opened from the gauger's platform.

d.

One-ground reading automatic level gauge with digital readout, float, and float well, including all necessary nozzles, mounting brackets, supports, guides, and hardware required and installed for a complete assembly.

e.

Automatic floating roof vents.

f.

Rim vents under mechanical primary seal.

g.

A guide device to prevent rotation of the roof.


DATE: 01 MAY 2003



h.

A roof drain extending to a shell nozzle in form of articulated pipes unless hose pipe is specified on tank drawing or data sheets.

i.

Emergency roof drains for double deck floating roof.

j.

Adjustable roof support legs for a high (maintenance) setting of 6 ft.-6 in. (2.0 m) and a low (operating) setting as determined by the tank manufacturer to clear internals, mixers, etc. The support legs shall be provided with bearing plate at bottom for internally lined tanks.

k.

A rolling ladder with self-leveling treads to permit access from the landing platform to the deck of the roof.

l.

One 20 inch (508 mm) diameter size manhole in each pontoon.

m. Positive electric bond from the floating roof deck to the tank shell. n.


o.

Flexible foam seal or mechanical primary seals as appropriate based on tank content and size. For epoxy lined tank, flexible foam seal shall be used.

p.

Secondary roof seals, in accordance with 40 CFR Part 60.112b, Subpart Kb, when specified by Purchaser or required by the local jurisdiction at site.

q.

Foam chambers, shields, dams, and piping, when specified.

r.


s.

Shell nozzles and supports for side-entering mixers, when specified.

t.

Level alarm and level transmitters when specified, including all necessary nozzles, mounting brackets, supports, guides, and hardware required and installed for a complete assembly.

5. COVERED FLOATING ROOF TANKS (INTERNAL FLOATING ROOFS) 5.1 General 5.1.1 The internal roof shall be either a steel pontoon type, aluminum pontoon type, or an aluminum honeycomb type. Roof shall be contact type to eliminate the presence of any air-vapor mixture under the deck. 5.1.2 Roof seal material shall be suitable for the stored products (e.g., aromatics). 5.2 Appurtenances and Accessories Internal floating roof tanks shall be furnished with the following: a.

The number of both fixed roof and floating roof manholes shall be per Subparagraph 3.2 (a) of this specification.

b.


c.

8 inch (200 mm) diameter gauge hatch with self-closing non-sparking cover and combination slotted gauge pole/roof anti-rotation pole.

d.

Internal ladder to permit access from the fixed roof to the deck of the floating roof.


DATE: 01 MAY 2003



e.

One ground-reading automatic level gauge with digital readout float, and float well, including all necessary nozzles, mounting brackets, supports, guides, and hardware required and installed for a complete assembly.

f.

A scaffold cable support for tanks over 18 feet (5.5 m) high.

g.

Automatic floating roof vents.

h.

Free vents and circulation vent openings with stainless steel bug screens for atmospheric tanks per API 650 Paragraph H.6.2.2 or, when specified, pressure vacuum vent valve(s) equipped with car seal open block valve(s) on the tank side for blanketed or low pressure tanks.

i.

Adjustable roof support legs for a high (maintenance) setting of 6 ft.-6 in.(2.0 m) and a low (operating) setting as determined by the tank manufacturer to clear internals, mixers, etc. The support legs shall be provided with bearing plate at bottom for internally lined tank.

j.

Positive electric bond from the roof deck to the tank shell.

k.

Flexible foam seal or mechanical primary seals as appropriate based on tank content and size. For internally lined tank, flexible foam seal shall be used.

l.

Secondary roof seals, in accordance with 40 CFR Part 60.112b, Subpart Kb, when specified by Purchaser or required by the local jurisdiction at site.

m. Foam chambers and piping, when specified. n.


o.

Shell nozzles and supports for side entering mixers, when specified.

p.


q.

Emergency vent when required by Paragraph 2.1.2.

r.

Level alarms and level transmitters when specified, including all necessary nozzles, mounting brackets, supports, guides, and hardware required and installed for a complete assembly.

6. MATERIAL 6.1 General 6.1.1 All material shall be new and as specified on tank drawings or data sheets. Use of alternate materials per API 650 Table 2-2 or 2-3 is subject to prior, written approval by Purchaser. 6.1.2 For epoxy or rubber lined tanks, the material for internals, appurtenance and accessories in contact with the stored liquid/vapor shall be compatible with the product. 6.2 Filler Materials Welding rods, electrodes, and wires shall be selected in accordance with KBR Technical Standard 4-7TS.


DATE: 01 MAY 2003



6.3 Supplementary Materials The tank manufacturer shall furnish blind flanges, manhole covers, bolts, and gaskets including one spare gasket for all manholes and all other nozzles specified to be furnished with blinds. 6.4 Gaskets Gaskets shall be 1/8 inch (3 mm) thick, compressed, non-asbestos fiber sheet unless otherwise specified on tank drawings or data sheets. The gasket material shall be compatible with the stored product. 6.5 Bolting Bolt heads and nuts shall be heavy hex. 7. FABRICATION 7.1 General 7.1.1 Holes shall not be cut into the shell for erection purposes. 7.1.2 Plate misalignment shall not be corrected by grinding off plate thickness to reduce offset. 7.1.3 Arc strikes on the tank shall be avoided. When they occur the surface shall be conditioned to eliminate surface stress raisers and shall be examined by the magnetic particle or liquid penetrant method. 7.1.4 Weld bevels for stub end nozzles shall be in accordance with the details and standards specified on the tank drawings or data sheets. 7.2 Welding 7.2.1 Welding shall be in accordance with the applicable construction code and KBR Technical Standard 4-7TS. 7.2.2 Fabrication involving welding shall not be sublet to others without the prior approval of the Purchaser. 7.2.3 The qualification of welding procedures for vertical joints shall include impact tests in accordance with API 650 Paragraph 7.2.2.3 when design metal temperature is below 50oF (10oC) and shall include impact tests in accordance with API 650 Paragraph 7.2.2.4 for all welding procedures for all components listed in API 650, Paragraph 2.2.9.1 including attachments to these components when design metal temperature is below 20oF (-6.7oC). 7.3 Tolerances Tank nozzles shall be installed within the following tolerances: a.

Projection from the inside of the tank to the face of flange ±1/8 inch (±3 mm).

b.

Elevation or orientation ±1/4 inch (±6 mm).

c.

Flange tilt in any plane ±1/2 degree but not to exceed 3/16 inch (5.0 mm).

d.

For hillside nozzles, from face of flange to centerline of tank and from centerline of tank to centerline of nozzle ±1/4 inch (6 mm).

e.

Flange bolt hole orientation ±1/16 inch (1.5 mm).


DATE: 01 MAY 2003



8. ADDITIONAL REQUIREMENTS FOR EPOXY & RUBBER LINED TANKS Tank fabricator shall comply with the design, fabrication and surface finish recommendations of NACE Standard RP0178 and the following requirements. Additionally, for rubber lined tanks, the recommendations of Rubber Manufacturer's Association (RMA) Technical Bulletins No. 1 & 2 shall be applicable. a.

For epoxy lined tanks, all internal welds shall be ground smooth and shall comply with NACE Standard weld designation D. For rubber lined tanks, all internal welds shall be ground flush and comply with NACE Standard weld designation A. Weld defects are not acceptable.

b.

All edges shall have a minimum of 1/8 inch (3.0 mm) radius.

c.

All internal surfaces shall be seal welded, skip welds are not acceptable.

d.

All surfaces shall be free of weld spatter. Undercuts, pinholes, gouges and pits shall be filled with weld metal.

e.

Tank internals which require bolted connections shall be of a corrosion resistant materials. This also includes all internal bolts, nuts and washers.

f.

Internals which cannot be easily blast cleaned and lined, such as piping elbows, long lengths of pipe, gauge wells, and floating roof support legs shall be made of corrosion resistant material.

g.

When tank roof is not lined, a supported roof may be used if the roof rafters are not in contact with product and the roof columns are lined similar to tank shell and bottom. The contacting surfaces between column bases and tank bottom shall be lined with a suitable corrosion resistant alloy before the application of lining material.

h.

Long weld neck or slip on flanges are preferred. Weld neck nozzles may be used provided the internal nozzle neck to flange weld can be ground smooth and flush. Nozzle necks and pipes made from plates shall have all internal weld reinforcement ground smooth and flush.

i.

For rubber lined tanks, the minimum nozzle size shall be NPS 4.

j.

For epoxy lined tanks, the minimum nozzle size shall be NPS 3, unless otherwise indicated on tank drawings or data sheets. Nozzles smaller than NPS 3 shall be of a corrosion resistant alloy and shall project a minimum of 1 inch (25 mm) into the tank.

k.

Threaded, carbon steel connections shall not be used for nozzles.

l.

Corrosion inhibitors and coatings shall not be applied to surfaces to be lined.

m. Carbon steel pad type (studded outlet) flanges may be used for nozzles sizes NPS 2 and larger for epoxy lined tanks only. n.

Steam and heater connections shall be designed to keep the temperature to which the lining will be exposed to below the maximum permissible for the lining material. Tank manufacturer shall submit design details for review and acceptance by Purchaser before the commencement of fabrication.

o.

Lining application shall commence only after tank is hydrotested, cleaned, and dried thoroughly.


DATE: 01 MAY 2003



9. INSPECTION, REJECTION, EXAMINATION, REPAIRS, AND TESTING 9.1 Inspection All materials and fabrication work shall be subject to inspection (shop and site) by the Purchaser. The manufacturer's drawings shall be made available to the Purchaser's inspector at the time of inspection. 9.2 Rejection 9.2.1 Completed tanks, parts of tanks, or materials containing defects originating with the manufacturer's design, materials, or workmanship; or that are not in complete compliance with the requirements of the Order will be rejected. 9.2.2 Discovery of such conditions after inspection and acceptance of the tank by the Purchaser does not relieve the manufacturer of his responsibility to comply with the requirements of the Order. 9.3 Examination 9.3.1 When complete or spot radiographs are taken at plate junctions, the film shall show at least 2 inches (51 mm) of weld length on each side of the vertical seam. At least 50% of the spot radiographs taken on vertical seams shall include intersections with horizontal seams. 9.3.2 The welds attaching the shell plate to the bottom plate shall be inspected by the magnetic particle or liquid penetrant method. 9.4 Repairs 9.4.1 Welds with defective areas shall have: a.

the defect removed

b.

confirmation of defect removal by magnetic particle or liquid penetrant examination

c.

repair welding using qualified welding procedures

d.

re-post weld heat treatment if originally required.

9.4.2 The finished weld-repair shall be radiographed if originally required, and the surface shall be reexamined by magnetic particle or liquid penetrant examination. If the repair involves serious alterations, the approval of the Purchaser shall be obtained before proceeding with the repair. 9.5 Testing 9.5.1 Testing shall be in accordance with API 650 Paragraph 5.3, F4.4 and F 7.6, as applicable. 9.5.2 Prior to the hydrotest, the inside of the tank shall be cleaned by sweeping, vacuuming, or other methods so that the tank will be "broom clean" and free of all trash, dirt, welding rod stubs, and other construction debris. 9.5.3 The tank manufacturer shall be responsible for conducting the tank hydrostatic test. Any limitations on filling rates or stage filling requirements for foundation consolidation will be specified by the Purchaser. 9.5.4 The hydrotest shall be conducted with all accessories and appurtenances installed.


DATE: 01 MAY 2003



9.5.5 Tanks constructed of austenitic stainless steel or austenitic stainless clad material shall be hydrotested with potable water only, with maximum chloride content of 250 ppm; no salt, brackish, or raw river water shall be used. Parts of a tank that cannot be completely drained shall be flushed with boiler condensate or demineralized water having a maximum chloride content of 50 ppm. 9.5.6 Unless specified otherwise, the Purchaser will make arrangements for the hydrotest water, including a supply of potable and/or 50 ppm maximum chloride content water if required. 9.5.7 After completion of the hydrotest, the tank manufacturer shall drain the tank and open the tank for inspection. Final cleaning of the tank will be by the Purchaser. 10. MARKING, PAINTING, AND SHIPPING 10.1 Marking 10.1.1 Stamping on all austenitic steel materials and impact tested materials shall be with "low stress" steel stamps having round or "U" shaped cross sections or with "interrupted dot" die stamps. 10.1.2 Marking paint or water insoluble ink for use on austenitic and high nickel alloy steels shall contain no substance (e.g., metallic pigments, sulfur, or chlorides) which would be harmful to these materials at ambient or elevated temperatures. The manufacturer shall submit analysis of marking material to the Purchaser. Submittal shall demonstrate (by chemical analysis and history of use) that the material meets these requirements. 10.1.3 Tank manufacturer shall provide name plate and certificate of compliance in accordance with API 650 Figure 8-1 and Figure 8-2. 10.2 Painting Surface preparation and painting shall be as specified on the tank drawings or data sheets. 10.3 Preparation for Shipment 10.3.1 All machined and threaded surfaces of carbon steel materials shall be coated with one of the following rust preventatives or equal approved by the Purchaser: E. F. Houghton Co. Exxon Chemical Co.

Rust-Veto No. 342 Rust-Ban No. 326

10.3.2 Weld bevels of carbon steel materials shall be coated with a weldable corrosion inhibitor such as one of the following rust preventatives or equal approved by the Purchaser: “Deoxaluminite” manufactured by:

AACCO 5220 N 125th Street Butler, Wisconsin 53007, USA Phone: (414) 781-7160 Fax: (414) 781-3558

“Aluminized Bloxide” manufactured by: Tempil Inc. 2901 Hamilton Blvd. South Plainfield, New Jersey 07080, USA Phone: (908) 757-8300 Fax: (908) 757-9273 10.4 Shipping Requirements and responsibilities for transporting material to the construction site shall be as specified in the Order.

API 650 Storage Tanks

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