ERPT_VAMED_Tank1_Final_7-28-06.pdf

EXECUTIVE SUMMARY

An API Standard 653 Out-of-Service Inspection of Tank #1 was completed on July 19, 2006. The purpose of this inspection was to collect data and establish a data base for present and future inspections and evaluations. A shell settlement survey was performed, and is beyond acceptable limits as set forth in API Standard 653 Appendix B. A shell service life evaluation performed on all shell courses shows that the shell has a remaining life of 495 years under current conditions, thereby, the next external visual inspection should be accomplished by a Certified Inspector prior to July 2011, and the next external ultrasonic thickness measurement inspection should be accomplished by a Certified Inspector prior to July 2021 in accordance with API Standard 653. A bottom service life evaluation shows that the out-of-service interval of operation (years to next internal inspection) to be 11 years under current conditions, thereby, the next internal inspection should be accomplished by a Certified Inspector prior to July 2017 in accordance with API Standard 653 unless repairs are made to increase the life of the bottom as recommended in Section 5.0. The fixed roof support columns do not have reinforcement plates.

Inspection Results are listed in 4.0. Recommendations for Compliance with API Standard 653 are made in 5.0, and Other Recommendations are made in 6.0.

ER-VAMED-TANK1

ii

TABLE OF CONTENTS

Section Page

Signature Page ............................................................................................................. i Executive Summary ................................................................................................... ii List of Appendices .................................................................................................... v List of Acronyms and Abbreviations ....................................................................... v

1.0 Introduction

1.1 Purpose

2.0 References

2.1 American Petroleum Institute

2.2 American Society of Mechanical Engineers

2.3 Code of Federal Regulations

2.4 National Association of Corrosion Engineers

2.5 National Fire Protection Association

3.0 Tank Description

4.0 Inspection Results

4.1 Containment

4.2 Foundation

4.3 Bottom

4.4 Shell

4.5 Shell Appurtenances

4.6 Accessways

4.7 Fixed Roof

5.0 Recommendations for Compliance with API Standard 653

5.1 Containment

5.2 Foundation

5.3 Bottom

5.4 Shell

5.5 Shell Appurtenances

5.6 Accessways

5.7 Fixed Roof

iii

TABLE OF CONTENTS (Continued)

Section Page

6.0 Other Recommendations

6.1 Containment

6.2 Foundation

6.3 Bottom

6.4 Shell

6.5 Shell Appurtenances

6.6 Accessways

6.7 Fixed Roof

7.0 Serviceability

LIST OF APPENDICES

Appendix A Engineering Calculations Appendix B Engineering Drawings Appendix C Engineering Data Appendix D API Standard 653 Checklists for Tank Inspection Appendix E Photographs iv

LIST OF ACRONYMS AND ABBREVIATIONS

API American Petroleum Institute ASME American Society of Mechanical Engineers

CFR Code of Federal Regulations CP Cathodic Protection

ETI Environmental Technology, Incorporated

MFL Magnetic Flux Leakage MT Magnetic Particle Testing

NACE National Association of Corrosion Engineers NDT Non-Destructive Testing NFPA National Fire Protection Association

PSI Pounds Per Square Inch PT Penetrant Testing

RP Recommended Practice RT Radiography Testing

UT Ultrasonic Testing

VT Visual Testing v

1.0 INTRODUCTION

1.1 Purpose:

1.1.1 This report provides an engineering evaluation of Tank #1 located at the Veterans Administration Medical Center facility in Martinsburg, West Virginia. This report summarizes the results of an API Standard 653 Out-of-Service Inspection conducted by Environmental Technology, Inc., Project Number 10399. This inspection was completed on July 19, 2006. Our policy is: "Provide to the storage tank owner and/or manager the most precise and complete inspection and report possible."

2.0 REFERENCES

2.1 American Petroleum Institute:

2.1.1 API Recommended Practice 574, Inspection Practices for Piping System Components.

2.1.2 API Recommended Practice 575, Inspection of Atmospheric and Low-Pressure Storage Tanks.

2.1.3 API Standard 650, Welded Steel Tanks for Oil Storage.

2.1.4 API Recommended Practice 651, Cathodic Protection of Aboveground Petroleum Storage Tanks.

2.1.5 API Recommended Practice 652, Lining of Aboveground Petroleum Storage Tank Bottoms.

2.1.6 API Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction.

2.2 American Society of Mechanical Engineers Codes:

2.2.1 ASME Boiler and Pressure Vessel Code; Section V, Non-Destructive Examination.

2.2.2 ASME Boiler and Pressure Vessel Code; Section IX, Welding and Brazing Qualifications.

2.2.3 ASME Boiler and Pressure Vessel Code; Section VIII, Division 1, Rules for Construction of Pressure Vessels.

2.3 Code of Federal Regulations:

2.3.1 29 CFR 1910, Permit-Required Confined Spaces for General Industry.

2.3.2 40 CFR 112, Oil Pollution Prevention.

2.4 National Association of Corrosion Engineers:

2.4.1 NACE Recommended Practice, RP0184-91, Repair of Lining Systems.

2.4.2 NACE Recommended Practice, RP0193-93, External Cathodic Protection of On-Grade Metallic Storage Tank Bottoms.

2.4.3 NACE Recommended Practice, RP0288-94, Inspection of Linings on Steel and Concrete.

2.5 National Fire Protection Association:

2.5.1 NFPA-30, Flammable and Combustible Liquids Code.

3.0 TANK DESCRIPTION

3.1 Tank Description:

Owner/Operator: Veterans Administration Medical Center Location: Martinsburg, West Virginia Tank Number: 1 Service: #2 Fuel Oil Specific Gravity: 0.87 Diameter: 23.5 feet Shell Height: 23.2 feet Maximum Level: 23.2 feet Capacity: 75,000 gallons; 1,800 barrels Configuration: Vertical Foundation: Concrete Ringwall Construction: Bottom: Lap-Welded

Shell: Course #1: Butt-Welded Course #2: Butt-Welded Course #3: Butt-Welded

Fixed Roof: Lap-Welded Material: Bottom: Carbon Steel, Unknown Grade

Shell: Course #1: Unknown Course #2: Unknown Course #3: Unknown

Fixed Roof: Carbon Steel, Unknown Grade Built: 1972 Age: 34 years Operating Limits: Minimum Metal Temperature: 10oF

Maximum Metal Temperature: Ambient Minimum Pressure: Atmospheric (no vacuum) Maximum Pressure: Product

Seismic Zone: 1 Construction Code: API Standard 650 Inspection Type: Out-of-Service Inspection Inspection Date: July 19, 2006 Last External Visual Inspection Year:

Last External Ultrasonic Thickness Inspection Year: 1972 Last Out-of-Service Inspection Year:

4.0 INSPECTION RESULTS

4.1 Containment: The secondary containment area is concrete. The secondary containment appears to be properly graded to drain water away from the tank bottom in accordance with NFPA 30-2.3.4.3(a). The secondary containment area has a dike drain and is in satisfactory condition. The secondary containment area volume appears to be sufficient to contain the stored product and to be impervious to the stored product. Overall, the secondary containment is in satisfactory condition.

4.2 Foundation: The foundation consists of a concrete ringwall. The bottom-to-foundation sealant is in satisfactory condition with minor gaps between the ringwall and floor extension.

The foundation was evaluated for shell settlement and is beyond acceptable limits as set forth in API Standard 653 Appendix B. Overall, the foundation is in satisfactory condition.

4.3 Bottom: The tank has a lap-welded cone up bottom. The nominal thickness of the bottom is 0.25 inches. The bottom was scanned (approximately 95%) for underside corrosion using Magnetic Flux Leakage (MFL) technology. Three (3) areas of underside corrosion were located with the thinnest area having 0.147 inches of metal remaining. Areas of underside corrosion are shown on the Bottom Layout drawing in Appendix B and are listed in the Bottom Plate Flaw Measurements table in Appendix C. The bottom was examined visually with the aid of a light held parallel to the bottom plates, which illuminates pitting and other discrepancies. The bottom has several areas of widely scattered stockside pitting with a maximum pit depth of 0.03 inches.

There is an indentation on Plate #2 that is approximately two inches (2") in diameter, the source of this indentation is unknown.The indentation is shown on the Bottom Layout drawing in Appendix B. Random thickness measurements of the bottom plates range from a minimum of

0.234 inches to a maximum of 0.260 inches, excluding the underside corrosion indications located by the MFL scan. Random thickness measurements are listed in the Bottom Plate Thickness Measurements table in Appendix C. A bottom service life evaluation shows that the in-service interval of operation (years to next internal inspection) to be 11 years under current conditions, thereby, the next internal inspection should be accomplished by a Certified Inspector prior to July 2017 in accordance with API Standard 653 unless repairs are made to increase the life of the bottom as recommended in 5.0. The bottom service life evaluation is shown in Appendix A. The bottom lap welds were tested with a vacuum box and are in satisfactory condition. The shell-to-bottom weld was tested with a right angle vacuum box and is in satisfactory condition. The fixed roof support columns do not have reinforcement plates installed between the columns and bottom plates as required by API Standard 653 Section 9.10.2.1.7 and item C.2.6.2.c of the Out-of-Service Checklist in Appendix D.

4.4 Shell: The tank consists of three (3) butt-welded courses. The exterior of the shell has a thin coating system ranging between 7.5 and 11.8 mils in thickness. The exterior coating of the shell is in satisfactory condition with spotted coating breaks and surface rust. The shell was evaluated for remaining metal thickness using ultrasonic technology. Thickness measurements are listed in the Shell Plate Thickness Measurements table in Appendix C. A shell service life evaluation performed on all shell courses shows that the shell has a remaining life of 495 years under current conditions, thereby, the next external visual inspection should be accomplished by a Certified Inspector prior to July 2011, and the next external ultrasonic thickness measurement inspection should be accomplished by a Certified Inspector prior to July 2021 in accordance with API Standard 653. The shell service life evaluation is shown in the Shell Service Life Evaluation table in Appendix A. Roundness, plumbness, peaking, and banding of the shell are within the allowable tolerances of API Standard 653. The shell is in satisfactory condition.

4.5 Shell Appurtenances: The nozzles and reinforcement plates were evaluated in accordance with API Standards 650 and 653 and are in satisfactory condition. The product level is monitored by a standard ATG and by an electronic level indicator. The ATG accuracy was tested against actual soundings and is within the two (2) inch tolerance of API Standard 653. The ATG system is in satisfactory condition.

4.6 Accessways: The fixed roof is accessible via a spiral stairway The fixed roof accessway has diamond tread with a 2 inch angle handrails. The fixed roof accessway is welded directly to the shell as opposed to reinforcement pads as required by API Standard 653. The accessway has coating failure and surface rust. The accessway is not anchored to the containment floor.

Overall, the accessway is in satisfactory condition.

4.7 Fixed Roof: The fixed roof is a supported cone roof. The coating system has minor breaks with surface and active corrosion. The nominal thickness of the fixed roof is 0.1875 inches. The fixed roof was evaluated for remaining metal thickness using ultrasonic technology. The fixed roof thickness ranges from a minimum of 0.162 inches to a maximum of 0.191 inches.

Thickness measurements are listed in the Fixed Roof Plate Thickness Measurements table in Appendix C. The fixed roof has minor debris (copper tubing) laying on top, this could be a potential tripping hazard. Overall, the fixed roof is in satisfactory condition.

5.0 RECOMMENDATIONS FOR COMPLIANCE

WITH API STANDARD 653

5.1 Containment: None.

5.2 Foundation: Re-seal any breeches in the foundation to floor sealant.

5.3 Bottom: Install 1/4inch lap-welded reinforcement plates between the fixed roof support column base and the bottom plates. Install patch plates over three (3) areas of underside corrosion. All reinforcement and patch plates should be installed per API Standard 653.

5.4 Shell: None.

5.5 Shell Appurtenances: None.

5.6 Accessways: None.

5.7 Fixed Roof: Remove debris (copper tubing) from atop the fixed roof.

6.0 OTHER RECOMMENDATIONS

6.1 Containment: None.

6.2 Foundation: None.

6.3 Bottom: Remove internal indentation from plate #2 and install 1/4" patch plate.

6.4 Shell: Recoat spot areas of coating breaks and surface rust.

6.5 Shell Appurtenances: None.

6.6 Accessways: Recoat spot areas of coating breaks, active corrosion and/or surface rust.

7.0 SERVICEABILITY

7.1 Upon completion of the repairs to Tank #1 described in 5.0, the tank will be in compliance with the requirements of API Standard 653, and the following schedule may be implemented:

7.1.1 The next external visual inspection should be accomplished by a Certified Inspector prior to July 2011 in accordance with API Standard 653.

7.1.2 The next external ultrasonic thickness measurement inspection should be accomplished by a Certified Inspector prior to July 2021 in accordance with API Standard 653.

7.1.3 The next internal inspection should be accomplished by a Certified Inspector prior to July 2026 in accordance with API Standard 653 only if repairs are made to increase the life of the bottom as outlined in 5.3. Otherwise the next internal inspection should be accomplished by a Certified Inspector prior to July 2017 in accordance with API Standard 653.

Appendix A

Engineering Calculations

1.

2.

3.

Bottom Service Life Evaluation Internal Shell Settlement Evaluation Shell Service Life Evaluation

ER-VAMED-TANK#1

A-1

MRTbc = RTbc - Orbc(StPr + UPr)

MRTip = RTip - Orip(StPr + UPr)

Orbc = RTbc - MRTbc

(StPr + UPr)

Orip = RTip - MRTip

(StPr + UPr)

Where:

MRTbc or MRTip = Minimum remaining thickness at the end of the in-service period of operation, in inches.

Or or Orbc or Orip = In-service interval of operation (years to next internal inspection), in years; however, Or shall not exceed 20 years.

RTbc = Minimum remaining thickness from bottom side corrosion after repairs, in inches.

RTip = Minimum remaining thickness from internal corrosion after repairs, in inches.

StPr = Maximum rate of corrosion not repaired on the top side, in inches per year. StPr = 0 for coated areas of the bottom. The expected service life of the coating must equal or exceed Orip to use StPr = 0.

UPr = Maximum rate of corrosion on the bottom, in inches per year. To calculate the corrosion rate, use the minimum remaining thicknesses after repairs. Assume a linear rate based on the age of the tanks.

UPr = 0 for areas that have effective cathodic protection.

Note: For areas of a bottom that have been scanned by the magnetic flux leakage (or exclusion) process, and do not have effective cathodic protection, the thickness used for calculating UPr must be the lesser of the MFL threshold or the minimum thickness of corrosion areas that are not repaired. The MFL threshold is defined as the minimum remaining thickness to be detected in the areas inspected. The MFL unit used for scanning the bottom does not have a threshold set point. This unit visually displays all anomalies. The confidence level of this unit diminishes greatly for underside pitting/corrosion that is less than 0.04 inches in depth, based on company experience.

Areas of bottom side corrosion that are repaired should be evaluated with the corrosion rate for the repaired area unless the cause of corrosion has been removed. The evaluation is done by using the corrosion rate of the repaired area for UPr, and adding the patch plate (if used) thickness to the term "minimum of RTbc or RTip".

NOTE: The engineering data used to calculate the in-service interval of operation (Or) assumes the tank remains in the same service and all corrosion rates remain constant.

ER-VAMED-TANK#1

Bottom Service Life Evaluation

A-2

Present Condition: The tank bottom does not have a lining system. The tank bottom does not have a cathodic protection system. The tank bottom does not have leak detection or secondary containment under the tank bottom.

MRTbc or MRTip RTip RTbc StPr UPr

0.1 inches

0.21 inches

0.147 inches

0.0012 inches/year

0.003 inches/year

Orbc = RTbc - MRTbc = (0.147 - 0.1) = 11 years(StPr + UPr) (0.0012 + 0.003)

Orip = RTip - MRTip = (0.21 - 0.1) = 26 years(StPr + UPr) (0.0012 + 0.003)

Therefore, the in-service interval of operation (years to next internal inspection) is:

Or = 11 years

ER-VAMED-TANK#1

A-3

Repair Option #1 for the Repaired Areas: Repair all underside corroded areas that measure less than 0.147 inches of remaining metal with 1/4 inch patch plates.

MRTbc or MRTip RTip RTbc StPr UPr

0.1 inches

0.46 inches

0.397 inches

0.0012 inches/year

0.003 inches/year

Orbc = RTbc - MRTbc = (0.397 - 0.1) = 70 years(StPr + UPr) (0.0012 + 0.003)

Orip = RTip - MRTip = (0.46 - 0.1) = 85 years(StPr + UPr) (0.0012 + 0.003)

Therefore, the in-service interval of operation (years to next internal inspection) for the repaired areas is:

Or = 20 years

ER-VAMED-TANK#1

A-4

Repair Option #1 for the Unrepaired Areas: Repair all underside corroded areas that measure less than 0.147 inches of remaining metal with 1/4 inch patch plates.

MRTbc or MRTip RTip RTbc StPr UPr

0.1 inches

0.21 inches

0.147 inches

0.0012 inches/year

0.003 inches/year

Orbc = RTbc - MRTbc = (0.147 - 0.1) = 11 years(StPr + UPr) (0.0012 + 0.003)

Orip = RTip - MRTip = (0.21 - 0.1) = 26 years(StPr + UPr) (0.0012 + 0.003)

Therefore, the in-service interval of operation (years to next internal inspection) for the unrepaired areas is:

Or = 11 years

ER-VAMED-TANK#1

A-5

Maximum Permissible Out-of-Plane Deflection

| S | < 11L2Y

2EH

Where:

S L Y E H

Maximum permissible out-of-plane deflection, in feet.

Arc length between measurement points, in feet Yield strength, in pounds per square inch (psi) Young's modulus, in pounds per square inch (psi) Tank height, in feet

L Y E H S

9.23 feet 30,000 psi 29,000,000 psi

23.2 feet

0.0209 feet

ER-VAMED-TANK#1

Internal Shell Settlement Evaluation

A-6

Out-of-Plane Deflection

Si = Ui - (1/2Ui-1 + 1/2Ui+1) Where:

S U

Calculated out-of-plane deflection, in feet.

Out-of-Plane settlement of point "i", in feet (+) when above cosine curve (-) when below cosine curve

U1 U2 U3 U4 U5 U6 U7 U8

0.0003 0.0000

-0.0098 0.0250 0.0298 0.0000 0.0198 0.0050 feet feet feet feet feet feet feet feet

S1 S2 S3 S4 S5 S6 S7 S8

-0.0023 0.0048

-0.0223 0.0150 0.0173

-0.0248 0.0173

-0.0050 feet feet feet ** feet feet feet ** feet feet

** NOTE: The out-of-plane deflection is unsatisfactory since the magnitude of the highest calculated Si out-of-plane deflection, 0.0248 feet, exceeds the maximum permissible out-of-plane deflection, 0.0209 feet. However, based on past performance of 34 years and a minimum out-of-plane deflection of 0.3 inches, no repairs are recommended at this time.

ER-VAMED-TANK#1

Internal Shell Settlement Evaluation

A-7

Remarks/Legend:

Owner/Operator:

Inspection Firm:

Date: Revision Number: Revision Date:

Drawing Title: Tank Description: Drawing Number:

Veterans Administration Medical Center

Environmental Technology Inc.

07/24/06 N/A N/A

Tank #1 SS-1Internal Shell Settlement Evaluation

Point #1 is at Seam #1 and each point is 45 degrees apart to the left viewing from the inside.

Seam #1 is the first seam right of the first manway right of the ladder in the first shell course viewing from the inside.

Out-of-Plane Settlement

Shell Settlement

Cosine Function Curve

Feet

Points 6 7 8 1 2 3 4 5 6

3.98

3.99

4.00

4.01

4.02

4.03

4.04

4.05

A -8

The maximum inspection intervals are determined by the most restrictive shell course in regard to the remaining life and the corrosion rate calculations for each shell course using the following formulas:

tmin=

2.6(H-1)DG

SE

Lr= tact - tmin Cr= tprev - tact Iut= tact - tmin Iv= tact - tmin

Cr Y 2Cr 4Cr

Where:

tmin = The minimum acceptable shell thickness for each course, in inches; however, tmin shall not be less than 0.1 inch for any tank course.

tnorm = The nominal shell thickness, in inches.

tact = The current measured shell thickness, excluding pits and corrosion, in inches.

tprev = The previous measured shell thickness, excluding pits and corrosion or tnorm, in inches.

D = The nominal diameter of the tank, in feet.

H = The height from the bottom of each shell course to the maximum liquid level, in feet.

Hc = The calculated safe fill height, in feet, for the current product.

G = The highest specific gravity of the contents.

Y = Specified minimum yield strength of the plate; use 30,000 pounds per square inch if not known (N/A for riveted tanks).

T = The smaller of the specified minimum tensile strength of the plate or 80,000 pounds per square inch; use 55,000 psi if not known (N/A for riveted tanks).

S = The maximum allowable stress, in pounds per square inch. For welded tanks, use the smaller of 0.80Y or 0.429T for the bottom and the second course or the smaller of 0.88Y or 0.472T for all other courses. For riveted tanks, use S=21,000 psi. For elevated temperatures above 200OF, the maximum allowable stress shall be the smaller of 2/3 the minimum yield strength multiplied by the M-factor (M) of API-650 Appendix M or the product design stress value listed in Table 3-2 of API-650.

E = The original joint efficiency for the tank. Use Table 2-1 from API Standard 653 if original E is unknown; E=1.0 when evaluating the retirement thickness in a corroded plate, when away from welds or joints by at least the greater of one inch or twice the plate thickness. For riveted tanks, use E=1.0 for shell plates when greater than 6 inches from rivets; use the value of E from API-653 Table 2-1 when within 6 inches of rivets.

Lr = The remaining life of the shell, in years.

Cr = The shell corrosion rate, in inches per year.

Iut = The inspection interval for the next ultrasonic inspection, in years (not to exceed 15 years).

Iv = The inspection interval for the next visual external inspection, in years (not to exceed 5 years).

Y = The years between the previous measured shell thickness (tprev) and the current measured shell thickness (tact), in years.

ER-VAMED-TANK#1

Shell Service Life Evaluation

A-9

Present Condition:

Plate Material: Carbon Steel, Unknown Grade

D H G Y

23.5 feet

23.2 feet 0.87 34 years

Course No.

Course Height (feet)

Maximum Allowable

Stress (psi) (S)

Joint Efficiency

(E)

Previous Measured Thickness (inches)

(tprev)

Current Measured Thickness (inches)

(tact)

Minimum Acceptable Thickness (inches)

(tmin)

Corrosion Rate

(in./yr) (Cr)

Remaining Life

(years) (Lr)

Next Visual

Inspection (years)

(Iv)

Next Ultrasonic Thickness Inspection

(years) (Iut)

1 7.7 23,595 1.00 0.2500 0.247 0.1 0.000088 1,670 5 15 2 7.7 23,595 1.00 0.1875 0.204 0.1 0.0002* 520 5 15 3 7.7 25,960 1.00 0.1875 0.199 0.1 0.0002* 495 5 15

* Let Cr=0.0002 inches per year for calculation purposes.

The current measured thickness is based on the lowest ultrasonic thickness measurement for that course. The remaining life of the shell is 495 years under present conditions. The current maximum operating level of 23.2 feet is satisfactory. The next external visual inspection should be accomplished by a Certified Inspector prior to July 2011 in accordance with API Standard 653. The next external ultrasonic thickness measurement inspection should be accomplished by a Certified Inspector prior to July 2021 in accordance with API Standard 653.

ER-VAMED-TANK#1

Shell Service Life Evaluation

A-10

Appendix B

Engineering Drawings

1.

2.

3.

Bottom Layout Shell Layout Fixed Roof Layout

B-1

Inspection Firm:

Date: Revision Number: Revision Date:

Drawing Title: Tank Description: Drawing Number:

Veterans Administration Medical Center

Environmental Technology Inc.

07/24/06 N/A N/A

Tank #1 B-1Bottom Layout

Measured Inside Diameter is 23.2 feet.

Tank bottom has 9 plates.

GRAPHIC SCALE:

Dimensions are in feet.

y x NW y x

NE

y x

SEy x

SW

XY Orientation

XY Orientation is in reference to Plan North

4 5 6

7 8 9 Underside Corrosion

See Bottom Plate Flaw Measurements table for detailed measurements.

Manway

Roof Support Column

ATG Float

- Patch Plates

Internal Indentation

Inspection Firm:

Date: Revision Number: Revision Date:

Drawing Title: Tank Description: Drawing Number:

Veterans Administration Medical Center

Environmental Technology Inc.

07/24/06 N/A N/A

Tank #1 S-1Shell Layout

Seam #1 is the first seam left of the first manway left of the ladder in the first shell course viewing from the outside.

The number in the upper left corner of each plate identifies the plate by the course and position of the plate in that course.

10540

GRAPHIC SCALE:

Dimensions are in feet.

1-1

A B

C

2-1

3-1

1-2

D

ATG

2-2

3-2

1 2 3

A - 2" Product B - 1.5" Product C - 20" Manway D - 2" Drain

Inspection Firm:

Date: Revision Number: Revision Date:

Drawing Title: Tank Description: Drawing Number:

Veterans Administration Medical Center

Environmental Technology Inc.

07/24/06 N/A N/A

Tank #1 S-2Shell Layout

Seam #1 is the first seam left of the first manway left of the ladder in the first shell course viewing from the outside.

The number in the upper left corner of each plate identifies the plate by the course and position of the plate in that course.

10540

GRAPHIC SCALE:

Dimensions are in feet.

1-3

E

2-3

3-3

3 1

E - 3" Product

Inspection Firm:

Date: Revision Number: Revision Date:

Drawing Title: Tank Description: Drawing Number:

Veterans Administration Medical Center

Environmental Technology Inc.

07/24/06 N/A N/A

Tank #1 R-1Fixed Roof Layout

Measured Diameter is 23.3 feet.

Fixed roof has 16 plates.

GRAPHIC SCALE:

Dimensions are in feet.

y x NW y x

NE

y x

SEy x

SW

XY Orientation

XY Orientation is in reference to Plan North

4 5 6

7 8 9 10

11 12 13

14 15 16

A

B

C

D

E

A - 20" Manway B - 8" Gaugewell C - 1-1/2" Auto Tank Gauge D - 20" Auto Tank Gauge Hatch E - 8" Vent

Appendix C

Engineering Data

1.

2.

3.

4.

5.

6.

Bottom Plate Thickness Measurements Bottom Plate Flaw Measurements Shell Settlement Measurements Shell Plate Thickness Measurements Shell Nozzle and Nozzle Reinforcement Measurements Fixed Roof Plate Thickness Measurements

C-1

1 23

TYPE C

1 2

TYPE E

TYPE BTYPE A

TYPE D

Plate Number

Thickness Measurements (in inches)

Plate Type

Point Numbers

1 2 3 4 5

1 0.241 0.246 0.244 NA NA A

2 0.239 0.247 0.238 0.252 0.240 E

3 0.240 0.245 0.250 NA NA B

4 0.234 0.240 0.249 0.238 0.248 E

5 0.246 0.243 0.256 0.239 0.252 E

6 0.238 0.240 0.241 0.242 0.260 E

7 0.241 0.260 0.255 NA NA C

8 0.242 0.256 0.248 0.255 0.246 E

9 0.239 0.250 0.241 NA NA D

NOTE: The lowest UT measurements are in RED, and the highest UT measurements are in GREEN.

ER-VAMED-TANK#1

Bottom Plate Thickness Measurements

C-2

X Y

Y X

X

X

Y

Y

NW

SW

NE

SE

Reference Corner XY Orientation

Underside Corrosion Plate No.

Flaw No.

Remaining Metal (in inches)

Reference Corner

X-Coordinate (in inches)

Y-Coordinate (in inches)

5 1 0.155 SE 7.1 0.9

5 2 0.182 SE 7.1 3

7 3 0.147 NE 2.1 3.1

ER-VAMED-TANK#1

Bottom Plate Flaw Measurements

C-3

Internal Shell Settlement Point Number 1 2 3 4 5 6 7 8 Rod Height 4.04 4.05 4.03 4.04 4.02 3.98 4.01 4.02

NOTE: The Rod Height measurements are in feet. The Rod Heights are based on the actual height of the transit at the time of the data collection. This data should be only be used for this report. Shell Settlement Point #1 is at Vertical Shell Seam #1. The shell settlement points are numbered to the right as viewed facing the tank externally.

ER-VAMED-TANK#1

Shell Settlement Measurements

C-4

1 2 3

4 5 6

7 -----------------------------through----------------------------- Last

Point

(Typical)

Course #1 Point No.

Plate 1-1

Plate 1-2

Plate 1-3

1 0.262 0.259 0.261

2 0.259 0.247 0.263

3 0.258 0.261 0.264

4 0.268 0.266 0.261

5 0.261 0.257 0.269

6 0.249 0.261 0.261

7 0.266 0.270 0.264

8 0.261 0.268 0.260

9 0.252 0.271 0.272

10 0.259 0.269 0.269

11 0.261 0.268 0.261

12 0.266 0.264 0.251

13 0.268 0.265 0.261

14 0.252 0.261 0.266

NOTE: Thickness measurements are evenly spaced across the bottom of each plate. The thickness measurements are in inches. The lowest UT measurements are in RED, and the highest UT measurements are in GREEN for each shell course.

ER-VAMED-TANK#1

Shell Plate Thickness Measurements

C-5

Spiral Stairway (Drop #1) Point No.

Course #3

Course #2

Course #1

1 0.206 0.205 0.261

2 0.205 0.211 0.264

3 0.205 0.207 0.266

4 0.199 0.212 0.259

5 0.201 0.204 0.270

NOTE: Thickness measurements are evenly spaced down each course along the path of each drop. Each shell course starts with Point #1 at the top of the course and ends with the last point at the bottom of the course. Thickness measurements are in inches. The lowest UT measurements are in RED, and the highest UT measurements are in GREEN for each shell course.

ER-VAMED-TANK#1

Shell Plate Thickness Measurements

C-6

Nozzle Measurements Nozzle Desig.

Sheet Number Description

X-Coord (feet)

Y-Coord (feet)

Thickness Measurements (inches)

Nominal 0O 90O 180O 270O

A 1 2" Product 6.3 2.5 0.1540 0.150 0.147 0.153 0.151

B 1 1.5" Product 9.3 2.5 0.1450 0.145 0.139 0.138 0.141

C 1 20" Manway 18.5 2.5 0.3750 0.378 0.378 0.379 0.377

D 2 2" Drain 1.8 0.5 0.2180 0.259 0.256 0.249 0.249

E 3 3" Product 12.3 1 0.300 0.300 0.315 0.299 0.301

Nozzle Reinforcement Measurements Nozzle Desig.

Sheet Number Description

Width (inches)

Length (inches)

Thickness Measurements (inches)

Nominal 0O 90O 180O 270O

C 1 Diamond with Round Corners 66 55 0.250 0.249 0.248 0.250 0.251

E 3 Diamond with Round Corners 14 12 0.250 0.249 0.250 0.260 0.251

NOTE: The Sheet Number corresponds to the shell plate in the first shell course. The X-Coord is measured from the first seam left of the nozzle in the first shell course to the center of the nozzle. The Y-Coord is measured from the tank bottom to the center of the nozzle.

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Shell Nozzle and Nozzle Reinforcement Measurements

C-7

1 23

TYPE C

1 2

TYPE E

TYPE BTYPE A

TYPE D

Plate Number

Thickness Measurements (in inches)

Plate Type

Point Numbers

1 2 3 4 5

1 0.170 0.164 0.181 NA NA A

2 0.173 0.172 0.188 0.173 0.168 E

3 0.172 0.179 0.186 NA NA B

4 0.164 0.170 0.190 0.168 0.170 E

5 0.162 0.181 0.176 0.173 0.165 E

6 0.169 0.166 0.172 0.160 0.172 E

7 0.168 0.172 0.164 0.179 0.177 E

8 0.171 0.168 0.169 0.169 0.180 E

9 0.188 0.164 0.172 0.173 0.172 E

10 0.180 0.165 0.168 0.170 0.179 E

11 0.182 0.172 0.170 0.174 0.166 E

12 0.164 0.169 0.171 0.163 0.168 E

13 0.191 0.188 0.186 0.170 0.175 E

14 0.182 0.169 0.177 NA NA C

15 0.180 0.186 0.181 0.172 0.184 E

16 0.179 0.190 0.176 NA NA D

NOTE: The lowest UT measurements are in RED, and the highest UT measurements are in GREEN.

ER-VAMED-TANK#1

Fixed Roof Plate Thickness Measurements

C-8

Appendix D

API Standard 653 Checklist for

Tank Inspection

1.

2.

Tank In-Service Inspection Checklist Tank Out-of-Service Inspection Checklist

Checklist Legend:

- Item was satisfactory.

X - Item has comment (see section 4.0).

NA - Item was not applicable to this tank.

D-1

1.1 FOUNDATION

a. X Measure foundation levelness and bottom elevations.

1.1.1 Concrete Ring

a. Inspect for broken concrete, spalling and cracks, particularly under backup bars used in welding butt welded annular rings under the shell.

b. NA Inspect drain openings in ring, back of waterdraw basins and top surface of ring for indications of bottom leakage.

c. Inspect for cavities under foundation and vegetation against bottom of tank.

d. Check that runoff rainwater from the shell drains away from the tank.

e. X Check for settlement around perimeter of tank.

1.1.2 Asphalt

a. NA Check for settling of tank into asphalt base which would direct runoff rain water under the tank instead of away from it.

b. NA Look for areas where leaching of oil has left rock filler exposed, which indicates hydrocarbon leakage.

1.1.3 Oiled Dirt or Sand

a. NA Check for settlement into the base which would direct runoff rain water under the tank rather than away from it.

1.1.4 Rock

a. NA Presence of crushed rock under the steel bottom usually results in severe underside corrosion. Make a note to do additional bottom plate examination (ultrasonic, hammer testing or turning of coupons) when the tank is out of service.

1.1.5 Site Drainage

a. NA Check site for drainage away from the tank and associated piping and manifolds.

b. NA Check operating condition of dike drains.

1.1.6 Housekeeping

a. NA Inspect the area for buildup of trash, vegetation, and other inflammables buildup.

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Tank In-Service Inspection Checklist

D-2

1.2 SHELLS

1.2.1 External Visual Inspection

a. Visually inspect for paint failures, pitting, and corrosion.

b. Clean off the bottom angle area and inspect for corrosion and thinning on plate and weld.

c. Inspect the bottom-to-foundation seal.

1.2.2 Internal (Floating Roof Tank)

a. NA Visually inspect for grooving, corrosion, pitting, and coating failures.

1.2.3 Riveted Shell Inspection

a. NA Inspect external surface for rivet and seam leaks.

b. NA Locate leaks by sketch or photo (location will be lost when shell is abrasively cleaned for painting).

c. NA Inspect rivets for corrosion loss and wear.

d. NA Inspect vertical seams to see if they have been full fillet lap welded to increase joint efficiency.

e. NA If no record exists of vertical riveted seams, dimension and sketch (or photograph) the rivet pattern: number of rows, rivet size, pitch length, and note whether the joint is butt riveted or lap riveted.

1.2.4 Wind Girder (Floating Roof Tanks)

a. NA Inspect wind girder and handrail for corrosion damage (paint failure, pitting, corrosion product buildup), especially where it occurs at tack welded junctions, and for broken welds.

b. NA Check support welds to shell for pitting, especially on shell plates.

c. NA Note whether supports have reinforcing pads welded to shell.

1.3 SHELL APPURTENANCES

1.3.1 Manways and Nozzles

a. Inspect for cracks or signs of leakage on weld joints at nozzles, manways, and reinforcing plates.

b. Inspect for shell plate dimpling around nozzles, caused by excessive pipe deflection.

c. Inspect for flange leaks and leaks around bolting.

d. NA Inspect sealing of insulation around manways and nozzles.

e. NA Check for inadequate manway flange and cover thickness on mixer manways.

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D-3

1.3.2 Tank Piping Manifolds

a. Inspect manifold piping, flanges, and valves for leaks.

b. Inspect fire fighting system components.

c. Check for anchored piping which would be hazardous to the tank shell or bottom connections during earth movement.

d. Check for adequate thermal pressure relief of piping to the tank.

e. NA Check operation of regulators for tanks with purge gas systems.

f. Check sample connections for leaks and for proper valve operation.

g. Check for damage and test the accuracy of temperature indicators.

h. Check welds on shell-mounted davit clips above valves 6 inches and larger.

1.3.3 Autogauge System

a. NA Inspect autogauge tape guide and lower sheave housing (floating swings) for leaks.

b. Inspect autogauge head for damage.

c. Bump the checker on autogauge head for proper movement of tape.

d. Identify size and construction material of autogauge tape guide (floating roof tanks).

e. NA Ask operator if tape tends to hang up during tank roof movement (floating roof tanks).

f. Compare actual product level to the reading on the autogauge (maximum variation is

2 inches).

g. NA On floating roof tanks, when the roof is in the lowest position, check that no more than two feet of tape are exposed at the end of the tape guide.

h. NA Inspect condition of board and legibility of board-type autogauges.

i. Test freedom of movement of marker and float.

1.3.4 Shell-Mounted Sample Station

a. Inspect sample lines for function of valves and plugging of lines, including drain or return-to-tank line.

b. NA Check circulation pump for leaks and operating problems.

c. NA Test bracing and supports of sample system lines and equipment.

1.3.5 Heater (Shell Manway Mounted)

a. NA Inspect condensate drain for presence of oil indicating leakage.

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D-4

1.3.6 Mixer

a. NA Inspect for proper mounting flange and support.

b. NA Inspect for leakage.

c. NA Inspect condition of power lines and connections to mixer.

1.3.7 Swing Lines: Winch Operation

a. NA Nonfloating. Raise, then lower the swing line with the winch, and check for cable tightness to confirm that swing line lowered properly.

b. NA Floating. With tank half full or more, lower the swing line, then let out cable and check if swing has pulled cable tight, indicating that the winch is operating properly.

c. NA Indicator. Check that the indicator moves in the proper direction: Floating swing line indicators show a lower level as cable is wound up on the winch. Non-floating swing line indicators show the opposite.

1.3.8 Swing Lines: External Guide System

a. NA Check for leaks at threaded and flanged joints.

1.3.9 Swing Lines: Identify Ballast Varying Need

a. NA Check for significant difference in stock specific gravity.

1.3.10 Swing Lines: Cable Material and Condition

a. NA For non-stainless steel cable, check for corrosion over entire length.

b. NA All cable: check for wear or fraying.

1.3.11 Swing Lines: Product Sample Comparison

a. NA Check for water or gravity differences that would indicate a leaking swing joint.

1.3.12 Swing Lines: Target

a. NA Target should indicate direction of swing opening (up or down) and height above bottom where suction will be lost with swing on bottom support.

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D-5

1.4 ROOFS

1.4.1 Deck Plate Internal Corrosion

a. For safety, before accessing the roof, check with ultrasonic instrument or lightly use a ball peen hammer to test the deck plate near the edge of the roof for thinning.

(Corrosion normally attacks the deck plate at the edge of a fixed roof and at the rafters in the center of the roof first.)

1.4.2 Deck Plate External Corrosion

a. Visually inspect for paint failure, holes, pitting, and corrosion product on the roof deck.

1.4.3 Roof Deck Drainage

a. Look for indication of standing water. (Significant sagging of fixed roof deck indicates potential rafter failure. Large standing water areas on a floating roof indicate inadequate drainage design or, if to one side, an unlevel roof with possible leaking pontoons).

1.4.4 Level of Floating Roof

a. NA At several locations, measure distance from roof rim to a horizontal weld seam above the roof. A variance in the readings indicates a nonlevel roof with possible shell out-of-round, out-of-plumb, leaking pontoons or hangup. On small diameter tanks, an unlevel condition can indicate unequal loading at that level.

1.4.5 Gas Test Internal Floating Roof

a. NA Test for explosive gas on top of the internal floating roof. Readings could indicate a leaking roof, leaking seal system or inadequate ventilation of the area above the internal floating roof.

1.4.6 Roof Insulation

a. NA Visually inspect for cracks or leaks in the insulation weather coat where runoff rain water could penetrate the insulation.

b. NA Inspect for wet insulation under the weather coat.

c. NA Remove small test sections of insulation and check roof deck for corrosion and holes near the edge of the insulated area.

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D-6

1.4.7 Floating Roof Seal Systems

a. NA Measure and record maximum seal-to-shell gaps:

at low pump out at midshell at high liquid level

b. NA Measure and record annular space at 30 foot spacing (minimum of 4 quadrants) around roof and record. Measurements should be taken in directly opposite pairs.

c. NA Check if seal fabric on primary shoe seals is pulling shoes away from shell (fabric not wide enough).

d. NA Inspect fabric for deterioration, holes, tears, and cracks.

e. NA Inspect visible metallic parts for corrosion and wear.

f. NA Inspect for openings in seals that would permit vapor emissions.

g. NA Inspect for protruding bolt or rivet heads against the shell.

h. NA Pull both primary and secondary seal systems back all around the shell to check their operation.

i. NA Inspect secondary seals for signs of buckling or indications that their angle with the shell is too shallow.

j. NA Inspect wedge-type wiper seals for flexibility, resilience, cracks and tears.

1.5 ROOF APPURTENANCES

1.5.1 Sample Hatch

a. Inspect condition and functioning of sample hatch cover.

b. On tanks governed by Air Quality Monitoring District rules, check for the condition of seal inside hatch cover.

c. NA Check for corrosion and plugging on thief and gauge hatch cover.

d. Where sample hatch is used to reel gauge stock level, check for marker and tab stating hold off distance.

e. NA Check for reinforcing pad where sample hatch pipe penetrates the roof deck.

f. NA On floating roof sample hatch and recoil systems, inspect operation of recoil reel and condition of rope.

g. NA Test operation of system.

h. NA On ultra clean stocks such as JP4, check for presence and condition of protective coating or liner inside sample hatch (preventing rust from pipe getting into sample).

1.5.2 Gauge Well

a. Inspect visible portion of the gauge well for thinning, size of slots, and cover condition.

b. NA Check for a hold off distance marker and tab with hold off distance (legible).

c. NA On floating roofs, inspect condition of roof guide for gauge well, particularly the condition of the rollers for grooving.

ER-VAMED-TANK#1

D-7

d. If accessible, check the distance from the gauge well pipe to the tank shell at different levels.

e. If tank has a gauge well washer, check valve for leakage and for presence of a bull plug or blind flange.

1.5.3 Fixed Roof Scaffold Support

a. Inspect scaffold support for corrosion, wear, and structural soundness.

1.5.4 Autogauge: Inspection Hatch and Guides (Fixed Roof)

a. Check the hatch for corrosion and missing bolts.

b. Look for corrosion on the tape guide's and float guide's wire anchors.

1.5.5 Autogage: Float Well Cover

a. Inspect for corrosion.

b. Check tape cable for wear or fraying caused by rubbing on the cover.

1.5.6 Sample Hatch (Internal Floating Roof)

a. NA Check overall conditions.

b. NA When equipped with a fabric seal, check for automatic sealing after sampling.

c. NA When equipped with a recoil reel opening device, check for proper operation.

1.5.7 Roof-Mounted Vents (Internal Floating Roof)

a. NA Check condition of screens, locking and pivot pins.

1.5.8 Gauging Platform Drip Ring

a. NA On fixed roof tanks with drip rings under the gauging platform or sampling area, inspect for plugged drain return to the tank.

1.5.9 Emergency Roof Drains

a. NA Inspect vapor plugs for emergency drain: that seal fabric discs are slightly smaller than the pipe ID and that fabric seal is above the liquid level.

1.5.10 Removable Roof Leg Racks

a. NA Check for leg racks on roof.

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D-8

1.5.11 Vacuum Breakers

a. NA Report size, number and type of vacuum breakers. Inspect vacuum breakers. If high legs are set, check for setting of mechanical vacuum breaker in high leg position.

1.5.12 Rim Vents

a. NA Check condition of the screen on the rim vent cover.

b. NA Check for plating off or removal of rim vents where jurisdictional rules do not permit removal.

1.5.13 Pontoon Inspection Hatches

a. NA Open pontoon inspection hatch covers and visually check inside for pontoon leakage.

b. NA Test for explosive gas (an indicator of vapor space leaks).

c. NA If pontoon hatches are equipped with locked down covers, check for vent tubes.

Check that vent tubes are not plugged up. Inspect lock down devices for condition and operation.

1.6 ACCESSWAYS

1.6.1 Handrails

a. Identify and report type (steel pipe, galvanized pipe, square tube, angle) and size of handrails.

b. Inspect for pitting and holes, paint failure.

c. Inspect attachment welds.

d. Identify cold joints and sharp edges. Inspect the handrails and midrails.

e. NA Inspect safety drop bar (or safety chain) for corrosion, functioning and length.

f. NA Inspect the handrail between the rolling ladder and the gauging platform for a hazardous opening when the floating roof is at its lowest level.

1.6.2 Platform Frame

a. Inspect frame for corrosion and paint failure.

b. Inspect the attachment of frame to supports and supports to tank for corrosion and weld failure.

c. NA Check reinforcing pads where supports are attached to shell or roof.

d. Inspect the surface that deck plate or grating rests on for thinning and holes.

e. Check that flat-surface to flat-surface junctures are seal welded.

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D-9

1.6.3 Deck Plate and Grating

a. Inspect deck plate for corrosion-caused thinning or holes (not drain holes) and paint failure.

b. Inspect plate-to-frame weld for rust scale buildup.

c. Inspect grating for corrosion-caused thinning of bars and failure of welds.

d. Check grating tie down clips. Where grating has been retrofitted to replace plate, measure the rise of the step below and above the grating surface and compare with other risers on the stairway.

1.6.4 Stairway Stringers

a. Inspect spiral stairway stringers for corrosion, paint failure and weld failure. Inspect attachment of stairway treads to stringer.

b. Inspect stairway supports to shell welds and reinforcing pads.

c. X Inspect steel support attachment to concrete base for corrosion.

1.6.5 Rolling Ladder

a. NA Inspect rolling ladder stringers for corrosion.

b. NA Identify and inspect ladder fixed rungs (square bar, round bar, angles) for weld attachment to stringers and corrosion, particularly where angle rungs are welded to stringers.

c. NA Check for wear and corrosion where rolling ladder attaches to gauging platform.

d. NA Inspect pivot bar for wear and secureness.

e. NA Inspect operation of self-leveling stairway treads.

f. NA Inspect for corrosion and wear on moving parts.

g. NA Inspect rolling ladder wheels for freedom of movement, flat spots and wear on axle.

h. NA Inspect alignment of rolling ladder with roof rack.

i. NA Inspect top surface of rolling ladder track for wear by wheels to assure at least 18 inches of unworn track (track long enough).

j. NA Inspect rolling ladder track welds for corrosion.

k. NA Inspect track supports on roof for reinforcing pads seal welded to deck plate.

l. NA Check by dimensioning, the maximum angle of the rolling ladder when the roof is on low legs.

Maximum angle.

m. NA If rolling ladder track extends to within five feet of the edge of the roof on the far side, check for a handrail on the top of the shell on that side.

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D-10

2.1 OVERVIEW

a. Check that tank has been cleaned, is gas free, and safe for entry.

b. Check that the tank is completely isolated from product lines, all electrical power, and steam lines.

c. Check that roof is adequately supported, including fixed roof structure and floating roof legs.

d. Check for presence of falling object hazards, such as corroded-through roof rafters, asphalt stalactites, and trapped hydrocarbons in unopened or plugged equipment or appurtenances, ledges, etc.

e. Inspect for slipping hazards on the bottom and roof decks.

f. Inspect structural welds on accessways and clips.

g. Check surfaces needing inspection for a heavy-scale buildup and check weld seams and oily surfaces where welding is to be done. Note areas needing more cleaning, including blasting.

2.2 TANK EXTERIOR

a. Inspect appurtenances opened during cleaning such as lower floating swing sheave assemblies, nozzle interiors (after removal of valves).

b. Hammer test or ultrasonically test the roof.

c. NA Enter and inspect the floating roof pontoon compartments.

2.3 BOTTOM INTERIOR SURFACE

a. Using a flashlight held close to and parallel to the bottom plates, and using the bottom plate layout as a guide, visually inspect and hammer test the entire bottom.

b. Measure the depth of pitting and describe the pitting appearance (sharp edged, lake type, dense, scattered, etc).

c. Mark areas requiring patching or further inspection.

d. Mark locations for turning coupons for inspection.

e. Inspect all welds for corrosion and leaks, particularly the shell-to-bottom weld.

f. Inspect sketch plates for corrosion.

g. Locate and mark voids under the bottom.

h. Record bottom data on a layout sketch using the existing bottom plates as a grid.

List the number and sizes of patches required.

i. Vacuum test the bottom lap welds.

j. Hammer test or ultrasonically examine any slightly discolored spots or damp areas.

k. X Check for reinforcing pads under all bottom attached clips, brackets, and supports.

l. NA Inspect floating roof leg pads for pitting or cutting, and excessive dimpling

(indicating excessive loading).

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Tank Out-of-Service Inspection Checklist

D-11

m. X Check the column bases of fixed roof supports for adequate pads and restraining clips.

n. In earthquake zones 3 and 4, check that roof supports are not welded down to the tank bottom, but are only restrained from horizontal movement.

o. NA Check area beneath swing line cable for indications of cable cutting or dragging.

p. NA Mark old oil and air test connections for removal and patching.

q. Identify and report low areas on the bottom that do not drain adequately.

r. NA Inspect coating for holes, disbonding, deterioration, and discolorization.

2.4 SHELL SEAMS AND PLATE

a. On cone up bottoms, closely inspect and gauge the depth of metal loss on the lower 2 to 4 inches of the shell (area of standing liquid).

b. Measure the depth of pitting on each course.

c. NA Inspect and estimate the amount of metal loss on the heads of rivets and bolts.

d. NA Inspect shell-to-bottom riveted lap joints.

e. NA Inspect for vertical grooving damage from seal assembly protrusions.

f. NA Inspect existing protective coatings for damage, deterioration, and disbonding.

g. NA Check for areas of rubbing (indicating too much pressure by the seal assembly shoes or inadequate annular space).

h. Visually inspect the shell plates and seams for indications of leakage.

i. NA If the shell has riveted or bolted seams, record the leak locations by film or chart in case the locations are lost during surface preparation for painting.

j. NA Measure annular space at 40-foot intervals.

k. Survey the shell to check for roundness and plumb.

2.5 SHELL-MOUNTED OVERFLOWS

a. NA Inspect overflow for corrosion and adequate screening.

b. NA Check location of overflow that it is not above any tank valves or equipment.

2.6 ROOF INTERIOR SURFACE

2.6.1 General

a. Visually inspect the underside surface of the roof plates for holes, scale buildup and pitting.

b. Hammer test or ultrasonically examine to check for thin areas, particularly in the vapor space of floating roofs and at the edge of the roof on cone roof tank.

c. Check all clips, brackets, braces, etc., welded to the…