Attachment J Fac 90198 FINAL-2019.pdf

US Army Corps of Engineers Omaha District

API 653 Out-of-Service Inspection Report

Robert Gray AAF, Texas Facility Number 90198

East Tank

US Army Corps of Engineers Center of Expertise for Petroleum, Oils and Lubricants

(USACE POL-MCX)

19 April 2019

API 653 Out-of-Service Inspection Report Robert Gray AAF, TX

Table of Contents

ACRONYMS AND ABBREVIATIONS

GENERAL SUMMARY

INSPECTION DATE

STATE REGULATIONS

PREVIOUS INSPECTION DATES

RECOMMENDED FUTURE INSPECTION DATES (CALCULATIONS SHALL BE PROVIDED)

GENERAL TANK INFORMATION

A. GENERAL PROJECT INFORMATION

1. API 653 Inspection

2. Site Information

B. TANK INSPECTION COMMENTS

1. Tank Construction

2. Tank Foundation

3. Tank Bottom

4. Tank Shell

5. Tank Appurtenances

6. Tank Coating

7. Tank Piping System

8. Fire Protection System

9. Secondary Containment

10. Cathodic Protection

C. FINDINGS AND RECOMMENDATIONS

1. MANDATORY REPAIRS per API 653, UFC 3-460-01, or AW 78-24-27 Standards

2. REQUIRED REPAIRS to Fully Comply with API 653, UFC 3-460-01, or AW 78-24-27 Standards

3. RECOMMENDED REPAIRS as Part of Regular Maintenance

APPENDIX A: ENGINEERING CALCULATIONS AND DRAWINGS

SHELL SETTLEMENT SURVEY

SHELL THICKNESS CALCULATION

SHELL UT MEASUREMENTS

FOOR THICKNESS CALCULATION

FLOOR UT MEASUREMENTS

ROOF THICKNESS CALCULATION

ROOF UT MEASUREMENTS

SHELL NOZZLE THICKNESS CALCULATION

SHELL NOZZLE UT MEASUREMENTS

CRITICAL ZONE SHELL THICKNESS

SHELL LAYOUT DRAWING

ROOF LAYOUT DRAWING

FLOOR LAYOUT DRAWING

NEXT INSPECTION

OSHA ACCESS STRUCTURE REPORT

APPENDIX B: 3-D DOCUMENTATION AND ANALYSIS

OUT OF PLUMBNESS (VERTICALLY)

ISOLATED SHELL DISTORTION

OUT-OF-ROUNDNESS

APPENDIX D: API 653 CHECKLISTS FOR TANK INSPECTIONS

APPENDIX E: PHOTOGRAPHS

API STANDARD 653

recommends that this document containing valuable historical information be retained

For the life of this tank.

ACRONYMS AND ABBREVIATIONS

API American Petroleum Institute

ASME American Society of Mechanical Engineers

ASNT American Society of Non-Destructive Testing

ATG Automatic Tank Gauge

BBL Barrel

CFR Code of Federal Regulations

CP Cathodic Protection

DFT Dry Film Thickness

HLA High Level Alarm

HLCS High Level Control Shutoff

HHLA High-High Level Alarm

LLA Low Level Alarm

LLLA Low-Low Level Alarm

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

P/V Pressure/Vacuum

RP Recommended Practice

PST Product Saver Tank

RT Radiography Testing

TML Thickness Measurement Location

TRV Thermal Relief Valve

UFC Unified Facilities Criteria

UFGS Unified Facilities Guide Specifications

ULS Ultra Low Sulfur

UT Ultrasonic Testing

VT Visual Testing

GENERAL SUMMARY

Tank 90198 is located at Robert Gray AAF, Killeen, Texas and is a welded, steel, vertical aboveground jet fuel (F‐24) storage tank. The tank was built per API 650 9th edition in 1984 and the manufactured by Chicago Bridge & Iron. Tank 90198 is 48'‐0" in diameter and has a maximum liquid level of 39'‐4" high per the certified strapping chart. The out of‐service inspection was performed April 19, 2019, and the results of this inspection will provide recommendations for repairs and upgrades which are required to comply with applicable industry and military standards. The testing and inspection was performed in accordance with the applicable sections of the Fifth Edition of API 653. Contained in this report is a detailed account of the tank inspection, a summary of the non‐destructive testing, and the conclusions derived from the inspection and testing.

INSPECTION DATE

API Out-of-Service (Internal) Inspection Date: 19 April 2019

Equipment Used:

Manufacturer: Dakota Ultrasonic’s Model Number: CMX DL Calibration Method: Zeroing Procedure, Multi-step Thickness gauge

Manufacturer: MFE Enterprises Tank Floor Scanner Model Number: MFE 2412 Mark III Calibration Method: Calibration Plate with Known Defects

Inspectors:

John Hester API 653 NDE Level II

STATE REGULATIONS

State Regulation for API In-Service Tank Inspections N/A State Regulation for API Out-of-Service Tank Inspections N/A

NOTE: If there are no state regulations for tank inspections then N/A shall reside in-place of the number of years between inspections. If state regulations reside, the recommended future inspections dates shall be based on whichever is more stringent between the API inspector’s calculations and the State regulations.

PREVIOUS INSPECTION DATES

API Out-of-Service (Internal) Inspection Date: 11 April 2008 API In-Service (External) Inspection Date: 5 May 2016

RECOMMENDED FUTURE INSPECTION DATES (CALCULATIONS SHALL BE PROVIDED)

API Out-of-Service (Internal) Inspection Date: 19 April 2039 API In-Service (External) Inspection Date: 19 April 2024 Ultrasonic Thickness Testing (UT) 19 April 2034

John Hester Hasan Daysal, P.E.

Project Manager/Inspector Engineer Robert and Company Robert and Company API 653 No. 88616 API 653 No. 27811 STI/SP001 No. AST-2092 ASNT NDT Level II No. 164397

GENERAL TANK INFORMATION

ITEM DESCRIPTION

Owner U.S. ARMY

Location Robert Gray AAF

Facility Number 90198

Tank Number East

State / Country Texas

City Killeen

Inspection Date 19 April 2019

Tank Manufacturer Chicago Bridge and Iron ( per previous report)

Design Standard API 650

Date of Construction 1984 (per previous report)

Tank Contents Jet Fuel/F-24

Tank Serial Number N/A

Tank Diameter 48’

Shell Height 42’

Product Height 39’ 4”

Tank Capacity 13,399 BBL (per previous report)

Foundation Concrete ringwall

Construction

Bottom Cone down lap welded plates

Shell Butt welded steel plates

Floating Roof Aluminum floating pan

Fixed Roof Lap welded steel plates

Material

Bottom Unknown Carbon steel

Shell A 283C

Floating Roof Aluminum

Fixed Roof Unknown Carbon steel

Cathodic Protection Impressed Current

Interior Coating System Appears to be standard 3-coat epoxy bottom and 4 feet up interior shell

Exterior Coating System Appears to be standard epoxy-polyurethane 100% of exterior

Surfaces.

Level Gauging Mechanical tape gauge, ENRAF.

Overfill Protection HLA, HLCV

Piping Receipt 8” Carbon Steel

Issue 10” Carbon Steel

Low Suction 3” Carbon Steel

Water Draw-Off ¾” Carbon Steel

Level Alarms High Level Alarm (HLA) / Low Level Alarm(LLA)

Type of Internal Floating Roof

Aluminum Honeycomb with a Double wiper seal

A. GENERAL PROJECT INFORMATION

1. API 653 Inspection

An OOS API 653 inspection was performed 19 April 2019 on Tank 90198 (East Tank). Results of this inspection identified recommended repairs and upgrades required to comply with API 650/653, UFC 3-460-01, 3-460-03, AW 78-24-27 and industry standards.

2. Site Information

Robert Gray Army Airfield is a military joint-use airport that operates alongside Killeen–Fort Hood

Regional Airport. The airport is based inside the south end of the Fort Hood Military Reservation

(known as East Fort Hood). The base was named after a Killeen native who was a pilot of a B-25 bomber on the famous Doolittle Raid on Tokyo in 1942. He was killed later in World War II flying combat missions.

B. TANK INSPECTION COMMENTS

1. Tank Construction

Tank 90198 is located at Robert Gray AAF, Killeen, Texas and is a welded, steel, vertical aboveground jet fuel (F‐24) storage tank. The tank was built per API 650 in 1984 and the manufactured by Chicago Bridge and Iron. Tank 90198 is 48'‐0" in diameter and has a maximum liquid level of 39'‐4" high per the certified strapping chart.

2. Tank Foundation

The tank is supported on a 6” Concrete ringwall. The ringwall has underside leak detection “telltales” in its perimeter, Conduit penetrating ringwall indicates that cathodic protection was installed for the new tank bottom. The tank is not anchored to the ringwall. The bottom-to-ringwall seal is in a minor state of deterioration. A settlement evaluation was performed during the inspection. No signs of settlement were noted. See Appendix A for settlement results.

3. Tank Bottom

The tank bottom is of cone-down construction with a 48’ diameter. The tank bottom was examined using a magnetic flux leakage (MFL) bottom scan, ultrasonic thickness testing (UTT), and visual testing (VT) methods. The MFL bottom scan yielded no soil-side or top-side indications. Five

(5) UTT measurements were taken on each bottom plate. UTT measurements yielded no significant metal loss on bottom plates. VT was performed on the bottom plate lap-welds and the bottom-to-shell weld. No visual surface defects or indications were found. The tank has leak detection and secondary containment under the bottom.

https://en.wikipedia.org/wiki/Killeen%E2%80%93Fort_Hood_Regional_Airport https://en.wikipedia.org/wiki/Killeen%E2%80%93Fort_Hood_Regional_Airport https://en.wikipedia.org/wiki/Fort_Hood https://en.wikipedia.org/wiki/Doolittle_Raid

4. Tank Shell

The tank shell is equipped with five eight foot courses and one two foot top course butt-welded steel shell courses. Shell plates were examined using UTT and VT methods. Nine (9) UTT measurements were taken on each plate of the 1st shell course. Eight (8) UTT measurements were taken on the remaining shell courses using the spiral staircase for access. UTT measurements indicated no significant metal loss on shell plates.

5. Tank Appurtenances

a. Internal Floating Roof

The floating roof consists of aluminum honeycomb sandwich panels. The maximum seal-to-shell gap measured 0.0 inches. The annular space between the floating roof and the shell measured between 5 and 6 inches. A new double wiper seal system was installed on the floating roof. Additional aluminum honeycomb sandwich panels were added to the underside of the floating roof to provide extra flotation

b. Geodesic Dome Roof

N/A

c. Gauging

The tank is provided with an ENRAF gauging system, 8” gauging hatch for manual gauging, Varec model 2500 tape gauge for monitoring liquid level from the ground.

d. Level Alarms

The tank is provided with independent shell mounted High-Level alarm (HLA) and an independent low level alarm (LLA).

Stairs and Platforms

The tank is provided with a spiral staircase with an upper platform for roof access. The spiral staircase is not provided with a maintenance platform for Level alarm testing the access around the Level alarms is 17 inches and does not meet the minimum OSHA clearance of 22 inches.

e. Grounding and Bonding

The tank is equipped with two (2) grounding lugs. One cable is in good overall condition with no signs of damage or detachment, second cable is attached to tank using a “C” clamp.

6. Tank Coating

The exterior coating of the shell is in satisfactory condition. The interior of the shell has a thin coating system on the tank floor and four feet up the tank interior shell.

7. Tank Piping System

All nozzles are adequately reinforced. ¾ " Water Draw/Product Recovery, 8" Receipt, 10" Product Issue, 3" Stripper Line/By-Pass.

8. Fire Protection System

Full contact Internal Floating Roof

9. Secondary Containment

Tank 90198 is located within a concrete containment dike with an HTP Liner installed. No tears or holes were noted in the liner; however some areas appear delaminated during the inspection. A leak test was performed on the containment dike drainage system. The leak test revealed that the drainage system is liquid-tight with no indications of seepage. Secondary containment exceeds the requirements of UFC 3-460-01.

𝑠𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦 𝑐𝑜𝑛𝑡𝑎𝑖𝑛𝑚𝑒𝑛𝑡 = 165′ 𝜋 × 6′ = 128,229 𝑓𝑡3 = 22,851 𝑏𝑎𝑟𝑟𝑒𝑙𝑠

1 𝑓𝑜𝑜𝑡 𝑟𝑒𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑜𝑓 𝑤𝑎𝑙𝑙 = 165′ 𝜋 × 5′ = 106,858𝑓𝑡3 = 19,032 𝑏𝑎𝑟𝑟𝑙𝑒𝑠

10. Cathodic Protection

The tank has an impressed current cathodic protection system installed.

C. FINDINGS AND RECOMMENDATIONS

1. MANDATORY REPAIRS per API 653, UFC 3-460-01, or AW 78-24-27 Standards

Mandatory repairs represent items that require immediate attention, in order to prevent imminent risk to system operators, equipment integrity, or the adjacent environment. The tank should remain out of service until these repairs are completed.

No mandatory repairs are required for continued service.

2. REQUIRED REPAIRS to Fully Comply with API 653, UFC 3-460-01, or AW 78-24-27 Standards

Recommended repairs represent items that should be addressed in a timely manner in order to prevent future potential risks to system operators, equipment integrity, or the adjacent environment. These items may be required by Federal, State and Local Codes or by Military Criteria.

a. Title: Remove and install new stairs

OBSERVATION: TANK 90198 STAIRS DO NOT MEET OSHA REQUIREMENTS FOR ACCESS AROUND THE

LEVEL ALARMS AND STAIR TREADS ARE WELDED DIRECTLY TO THE TANK SHELL WELD SEAMS

REFERENCE: 29 CFR 1910.24(D)(H), AW – 78-24-27

RECOMMENDATION: BUILD NEW STAIRS TO ADD A MAINTENANCE PLATFORM

b. Title Install 2 inch DBB valve on product recovery tank and replace galvanized line with carbon steel or stainless steel

OBSERVATION: WATER DRAW OFF DOES NOT HAVE THE REQUIRED TWO INCH DOUBLE BLOCK AND BLEED

VALVE AND HAS GALVANIZED LINE INSTALLED

REFERENCE: AW-78-24-28

RECOMMENDATION: REMOVE ¾ INCH VALVE AND INSTALL A TWO INCH DOUBLE BLOCK AND BLEED PLUG

VALVE AND NEW PIPING TO THE PRODUCT RECOVERY TANK

c. Title: Receipt Line Remove sight glass and install test T section

OBSERVATION: THERMAL RELIEF DOES NOT HAVE A TEST T SECTION INSTALLED ON THE RECEIPT LINE, SIGHT GLASS INSTALLED

REFERENCE: AW-78-24-28

RECOMMENDATION: INSTALL THERMAL RELIEF TEST T SECTION AND REMOVE SIGHT GLASS.

d. Title: Issue Line Re-install Thermal Reliefs and add test T sections

OBSERVATION: THERMAL RELIEFS INSTALLED HORIZONTALLY, NO TEST T SECTIONS INSTALLED ON THE

ISSUE LINE

REFERENCE: AW-78-24-28

RECOMMENDATION: INSTALL THERMAL RELIEFS IN THE CORRECT VERTICAL POSITION AND TEST T

SECTIONS.

e. Title: Add NFPA Label

OBSERVATION: TANK 90198 DOES NOT HAVE THE REQUIRED NFPA LABEL

REFERENCE: AW-78-24-28, UFC 3-460-01

RECOMMENDATION: INSTALL NFPA LABEL

f. Title: Add Teflon pads and Teflon coated U Bolts

OBSERVATION: TANK 90198 DOES NOT HAVE THE REQUIRED TEFLON INSERTS OR COATED U-BOLTS ON

THE INTERNAL PIPE SUPPORTS

RECOMMENDATION: INSTALL TEFLON INSERTS AND COATED U-BOLTS ON THE INTERNAL PIPE SUPPORTS

g. Title: Install four perimeter roof vents/inspection hatches

OBSERVATION: TANK 90198 DOES NOT HAVE THE REQUIRED PERIMETER ROOF VENTS/INSPECTION

HATCHES INSTALLED PER THE STANDARD DESIGN

RECOMMENDATION: INSTALL THE REQUIRED PERIMETER ROOF VENTS/INSPECTION HATCHES

h. Title: Remove Internal roof corrosion

OBSERVATION: TANK 90198 ROOF INTERNAL CORROSION

RECOMMENDATION: BLAST AND COAT INTERNAL ROOF

i. Title: Install perimeter tank safety railing

OBSERVATION: TANK 90198 ONLY HAS A SAFETY RAILING INSTALLED FROM THE TANK STAIRS ACROSS

THE TANK TO THE ROOF ACCESS.

RECOMMENDATION: INSTALL NEW SAFETY RAILING AROUND THE PERIMETER OF THE TANK

j. Title: Grounding Lug

OBSERVATION: GROUND IS NOT PERMANENTLY ATTACHED TO TANK

REFERENCE: AW-78-24-28, API 650

RECOMMENDATION: ATTACH TO TANK WITH PROPER HARDWARE

k. Title: Floating pan support legs

OBSERVATION: SUPPORT LEGS DON’T HAVE TEFLON INSERTS CAUSING COATING FAILURE.

RECOMMENDATION: INSTALL TEFLON INSERTS

l. Title: Install High-High and Low-Low level alarms

OBSERVATION: TANK 90198 IS NOT EQUIPPED WITH A HIGH-HIGH AND LOW-LOW LEVEL ALARMS

RECOMMENDATION: INSTALL NEW HIGH-HIGH AND LOW-LOW LEVEL ALARMS

m. Title: 36” Manways

OBSERVATION: TANK 90198 DOESN’T HAVE 36” MANWAYS

RECOMMENDATION: INSTALL 36” MANWAYS

n. Title: Install Bolted Flanges to ¾ inch water draw line and Receipt Line

OBSERVATION: TANK 90198 WATER DRAW AND RECEIPT LINE DO NOT HAVE THE REQUIRED INTERNAL

TANK FLANGES.

RECOMMENDATION: INSTALL THE REQUIRED INTERNAL TANK FLANGES PER THE STANDARD DESIGN.

3. RECOMMENDED REPAIRS as Part of Regular Maintenance

Recommended repairs represent items that should be addressed in a timely manner in order to prevent future potential risks to system operators, equipment integrity, or the adjacent environment.

o. Title: Remove Valve Corrosion

OBSERVATION: TANK ISSUE VALVE CORROSION

REFERENCE: UFC 3-460-01

RECOMMENDATION: REMOVE CORROSION AND COAT

p. Title: Remove platform Corrosion

OBSERVATION: TANK PLATFORM CORROSION

REFERENCE: UFC 3-460-01

RECOMMENDATION: REMOVE CORROSION AND COAT

APPENDIX A: ENGINEERING CALCULATIONS AND DRAWINGS

SHELL SETTLEMENT SURVEY

SHELL THICKNESS CALCULATION

SHELL UT MEASUREMENTS

API 6

FOO

653 Out-of-S

R THICKNES

ervice Inspe

SS CALCULA

ction Report

ATION

t

Robert

Gray AAF, TX

X

FLOOR UT MEASUREMENTS

API 6

ROO

653 Out-of-S

OF THICKNES

ervice Inspe

SS CALCULA

ction Report

ATION

t

Robert

Gray AAF, TX

ROOF UT MEASUREMENTS

SHELL NOZZLE THICKNESS CALCULATION

SHELL NOZZLE UT MEASUREMENTS

CRITICAL ZONE SHELL THICKNESS

See course 1 thickness readings for critical zone.

SHELL LAYOUT DRAWING

ROOF LAYOUT DRAWING

FLOOR LAYOUT DRAWING

NEXT INSPECTION

OSHA ACCESS STRUCTURE REPORT

APPENDIX B: 3-D DOCUMENTATION AND ANALYSIS

OUT OF PLUMBNESS (VERTICALLY)

The tank was checked by using laser measurements taken from fixed locations at 8 points around tank from chime weld to the roof weld. The Tank’s plumbness is in satisfactory condition at this time.

ISOLATED SHELL DISTORTION

There was no significant shell distortion noted at this time.

OUT-OF-ROUNDNESS

APPENDIX D: API 653 CHECKLISTS FOR TANK INSPECTIONS

Tank In-Service Inspection Checklist

Item Completed

X

C.1.1 Foundation

Measure foundation levelness and bottom elevations (see Annex B for extent of measurements). X

C.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.

X b Inspect drain openings in ring, back of water draw basins and top surface of ring for indications of bottom leakage.

X c Inspect for cavities under foundation and vegetation against bottom of tank. X d Check that runoff rainwater from the shell drains away from tank. X e Check for settlement around perimeter of tank. X

C.1.1.2 Asphalt a Check for settling of tank into asphalt base which would direct runoff rain water under the tank instead of away from it.

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

C.1.1.3 Oiled Dirt or Sand

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

N/A

C.1.1.4 Rock

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.

N/A

C.1.1.5 Site Drainage a Check site for drainage away from the tank and associated piping and manifolds. X b Check operating condition of the dike drains. X

C.1.1.6 Housekeeping

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

C.1.1.7 Cathodic Protection

Review cathodic protection potential readings. X

C.1.2 Shells

C.1.2.1 External Visual Inspection a Visually inspect for paint failures, pitting, and corrosion. X b Clean off the bottom angle area and inspect for corrosion and thinning on plate and weld. X c Inspect the bottom-to-foundation seal, if any. X

C.1.2.2 Internal (Floating Roof Tank)

Visually inspect for grooving, corrosion, pitting, and coating failures. X

C.1.2.3 Riveted Shell Inspection a Inspect external surface for rivet and seam leaks. N/A b Locate leaks by sketch or photo (location will be lost when shell is abrasive cleaned for painting). N/A c Inspect rivets for corrosion loss and wear. N/A

Tank In-Service Inspection Checklist Continued

Item Completed

X d Inspect vertical seams to see if they have been full fillet lap-welded to increase joint efficiency. N/A e 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.

N/A

C.1.2.4 Wind Girder (Floating Roof Tanks) a Inspect wind girder and handrail for corrosion damage (paint failure, pitting, corrosion product buildup), especially where it occurs at tack-welded junction, and for broken welds.

N/A b Check support welds to shell for pitting, especially on shell plates. N/A c Note whether supports have reinforcing pads welded to shell. N/A

C.1.3 Shell Appurtenances

C.1.3.1 Manways and Nozzles a Inspect for cracks or signs of leakage on weld joint at nozzles, manways, and reinforcing plates. X b Inspect for shell plate dimpling around nozzles, caused by excessive pipe deflection. X c Inspect for flange leaks and leaks around bolting. X d Inspect sealing of insulation around manways and nozzles. X e Check for inadequate manway flange and cover thickness on mixer manways. X

C.1.3.2 Tank Piping Manifolds a Inspect manifold piping, flanges, and valves for leaks. X b Inspect fire fighting system components. X c Check for anchored piping which would be hazardous to the tank shell or bottom connections during earth movement.

X d Check for adequate thermal pressure relief of piping to the tank. X e Check operation of regulators for tanks with purge gas systems. X f Check sample connections for leaks and for proper valve operation. X g Check for damage and test the accuracy of temperature indicators. X h Check welds on shell-mounted davit clips above valves 6 in. and larger. X

C.1.3.3 Autogauge System a Inspect autogauge tape guide and lower sheave housing (floating swings) for leaks. X b Inspect autogauge head for damage. X c Bump the checker on autogauge head for proper movement of tape. X d Identify size and construction material of autogauge tape guide (floating roof tanks). X e Ask operator if tape tends to hang up during tank roof movement (floating roof tanks). X f Compare actual product level to the reading on the autogauge (maximum variation is 2 in.). X g On floating roof tanks, when the roof is in the lowest position, check that no more than two ft of tape are exposed at the end of the tape guide.

X h Inspect condition of board and legibility of board-type autogauges. X i Test freedom of movement of marker and float. X

C.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.

N/A b Check circulation pump for leaks and operating problems. N/A

Tank In-Service Inspection Checklist Continued

Item Completed

X c Test bracing and supports for sample lines and equipment. N/A

C.1.3.5 Heater (Shell Manway Mounted)

Inspect condensate drain for presence of oil indicating leakage. N/A

C.1.3.6 Mixer a Inspect for proper mounting flange and support. N/A b Inspect for leakage. N/A c Inspect condition of power lines and connections to mixer. N/A

C.1.3.7 Swing Lines: Winch Operation a Nonfloating. Raise, then lower the swing line with the winch, and check for cable tightness to confirm that swing line lowered properly.

N/A b 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.

N/A c 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.

N/A

C.1.3.8 Swing Lines: External Guide System

Check for leaks at threaded and flanged joints. N/A

C.1.3.9 Swing Lines: Identify Ballast Varying Need

Check for significant difference in stock specific gravity. N/A

C.1.3.10 Swing Lines: Cable Material and Condition a For non stainless steel cable, check for corrosion over entire length. N/A b All cable: check for wear or fraying. N/A

C.1.3.11 Swing Lines: Product Sample Comparison

Check for water or gravity differences that would indicate a leaking swing joint. N/A

C.1.3.12 Swing Lines: Target

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

N/A

C.1.4 Roofs

C.1.4.1 Deck Plate Internal Corrosion

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.)

X

C.1.4.2 Deck Plate External Corrosion

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

C.1.4.3 Roof Deck Drainage

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, a nonlevel roof with possible leaking pontoons.)

Tank In-Service Inspection Checklist Continued

Item Completed

C.1.4.4 Level of Floating Roof

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 hang-up. On small diameter tanks, an unlevel condition can indicate unequal loading at that level.

C.1.4.5 Gas Test Internal Floating Roof

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.

N/A

C.1.4.6 Roof Insulation a Visually inspect for cracks or leaks in the insulation weather coat where runoff rain water could penetrate the insulation.

N/A b Inspect for wet insulation under the weather coat. N/A c Remove small test sections of insulation and check roof deck for corrosion and holes near the edge of the insulated area.

N/A

C.1.4.7 Floating Roof Seal Systems a Inspect the condition of the seal, measure and record maximum rim spaces and seal to- shell gaps around the full roof circumference at the level of inspection.

NOTE Inspection of the seal and measurement of the rim spaces and seal-to-shell gaps at more than one level may be necessary to more fully determine if any problems exist at other levels of tank operation).

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

N/A

1) _______ _______ Opposite pair 1. N/A

2) _______ _______ Opposite pair 2. N/A c Check if seal fabric on primary shoe seals is pulling shoes away from shell (fabric not wide enough). N/A d Inspect fabric for deterioration, holes, tears, and cracks. N/A e Inspect visible metallic parts for corrosion and wear. X f Inspect for openings in seals that would permit vapor emissions. X g Inspect for protruding bolt or rivet heads against the shell. X h Pull both primary and secondary seal systems back all around the shell to check their operation. X i Inspect secondary seals for signs of buckling or indications that their angle with the shell is too shallow.

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

C.1.5 Roof Appurtenances

C.1.5.1 Sample Hatch a Inspect condition and functioning of sample hatch cover. X b On tanks governed by Air Quality Monitoring District rules, check for the condition of seal inside hatch cover.

X c Check for corrosion and plugging on thief and gauge hatch cover. X d Where sample hatch is used to reel gauge stock level, check for marker and tab stating hold-off distance.

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

Completed

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

N/A g Test operation of system. N/A h 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).

N/A

C.1.5.2 Gauge Well a Inspect visible portion of the gauge well for thinning, size of slots, and cover condition. X b Check for a hold-off distance marker and tab with hold-off distance (legible). X c On floating roofs, inspect condition of roof guide for gauge well, particularly the condition of the rollers for grooving.

N/A d If accessible, check the distance from the gauge well pipe to the tank shell at different levels. N/A e If tank has a gauge well washer, check valve for leakage and for presence of a bull plug or blind flange.

N/A

C.1.5.3 Fixed Roof Scaffold Support

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

C.1.5.4 Autogauge: Inspection Hatch and Guides (Fixed Roof) a Check the hatch for corrosion and missing bolts. X b Look for corrosion on the tape guide’s and float guide’s wire anchors. X

C.1.5.5 Autogauge: Float Well Cover a Inspect for corrosion. X b Check tape cable for wear or fraying caused by rubbing on the cover. X

C.1.5.6 Sample Hatch (Internal Floating Roof) a Check overall conditions. X b When equipped with a fabric seal, check for automatic sealing after sampling. N/A c When equipped with a recoil reel opening device, check for proper operations. N/A

C.1.5.7 Roof-mounted Vents (Internal Floating Roof)

Check condition of screens, locking and pivot pins. X

C.1.5.8 Gauging Platform Drip Ring

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

C.1.5.9 Emergency Roof Drains

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.

N/A

C.1.5.10 Removable Roof Leg Racks

Check for leg racks on roof. N/A

C.1.5.11 Vacuum Breakers

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

X

C.1.5.12 Rim Vents a Check condition of the screen on the rim vent cover. X

Completed

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

C.1.5.13 Pontoon Inspection Hatches a Open pontoon inspection hatch covers and visually check inside for pontoon leakage. N/A b Test for explosive gas (an indicator of vapor space leaks). N/A c If pontoon hatches are equipped with locked down coves, check for vent tubes. Check that vent tubes are not plugged up. Inspect lock-down devices for condition and operation.

N/A

C.1.6.1 Access ways

See Tank Out-of-service Inspection Checklist, Item C.2.12. X

NOTES:

Tank Out-of-Service Inspection Checklist

Completed

X

C.2.1 Overview a Check that tank has been cleaned, is gas free, and safe for entry. X b Check that the tank is completely isolated from product lines, all electrical power, and steam lines. X c Check that roof is adequately supported, including fixed roof structure and floating roof legs. X 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.

X e Inspect for slipping hazards on the bottom and roof decks. X f Inspect structural welds on access ways and clips. X 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.

X h Review cathodic protection potential readings. X

C.2.2 Tank Exterior a Inspect appurtenances opened during cleaning such as lower floating swing sheave assemblies, nozzle interiors (after removal of valves).

X b Hammer test or ultrasonically test the roof. X c Enter and inspect the floating roof pontoon compartments. X

C.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.

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

X c Mark areas requiring patching or further inspection. X d Mark locations for turning coupons for inspection. X e Inspect all welds for corrosion and leaks, particularly the shell-to-bottom weld. X f Inspect sketch plates for corrosion. X g Check condition of internal sump, if applicable. Standing liquid should be removed from the sump to allow for complete inspection and vacuum testing of weld seams as appropriate. Sump bottom and sidewall plate and seams need to be evaluated for both product-side and soil-side corrosion.

X h Locate and mark voids under the bottom. X i Record bottom data on a layout sketch using the existing bottom plates as a grid. List the number and sizes of patches required. X j Vacuum test the bottom lap welds. N/A k Hammer test or ultrasonically examine any slightly discolored spots or damp areas. X l Check for reinforcing pads under all bottom attached clips, brackets, and supports. X m Inspect floating roof leg pads for pitting or cutting, and excessive dimpling (indicating excessive loading).

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

X

Tank Out-of-Service Inspection Checklist Continued

Item Completed

X p Check area beneath swing line cable for indications of cable cutting or dragging. N/A q Mark old oil and air test connection for removal and patching. N/A r Identify and report low areas on the bottom that do not drain adequately. X s Inspect coating for holes, disbonding, deterioration, and discoloration. X

C.2.4 Shell Seams and Plate a On cone up bottoms, closely inspect and gauge the depth of metal loss on the lower 2 in. to 4 in. of the shell (area of standing water).

X b Measure the depth of pitting on each course. X c Inspect and estimate the amount of metal loss on the heads of rivets and bolts. X d Inspect shell-to-bottom riveted lap joints. X e Inspect for vertical grooving damage from seal assembly protrusions. X f Inspect existing protective coatings for damage, deterioration, and disbonding. X g Check for areas of rubbing (indicating too much pressure by the seal assembly shoes or inadequate annular space).

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

X j Measure annular space at 40-ft intervals. X k Survey the shell to check for roundness and plumb. X

C.2.5 Shell-mounted Overflows a Inspect overflow for corrosion and adequate screening. X b Check location of overflow that it is not above any tank valves or equipment. X

C.2.6 Roof Interior Surface

C.2.6.1 General a Visually inspect the underside surface of the roof plates for holes, scale buildup, and pitting. X b Hammer test or ultrasonically examine to check for thin areas, particularly in the vapor space of floating roofs and at edge of roof on cone roof tank.

X c Check all clips, brackets, braces, etc., welded to the roof deck plate for welded reinforcing pads and see that they have not broken free.

X d If no pad is present, penetrant test for cracking of the weld or deck plate. X e Inspect for protective coating for breaks, disbondment, and deterioration. X f Spark test the interior surface coating if recoating is not planned. N/A

C.2.6.2 Fixed Roof Support Structure a Inspect the support columns for thinning in the upper 2 ft. X b On API columns (two channels welded together) check for corrosion scale breaking the tack welds, unless the joint between the channels is completely seal welded.

X c Check that the reinforcing pad on the bottom is seal-welded to the tank bottom with horizontal movement restraining clips welded to the pad.

X d Determine if pipe column supports are concrete filled or open pipe. If open pipe, check for a drain opening in the bottom of the pipe.

X

Tank Out-of-Service Inspection Checklist Continued

Item Completed

X e Inspect and gauge rafters for thinning, particularly near the center of the roof. Report metal loss. X f Check for loose or twisted rafters. X g Inspect girders for thinning and check that they are attached securely to the top of the columns. X h Report if the columns have cross bracing in the area between the low pump out of the top of the shell (for future internal floating roof installation).

X i Inspect and report presence of any roof-mounted swing line bumpers. X j Photograph the roof structure if no rafter layout drawing exists. X

C.2.7 Fixed Roof Appurtenances

C.2.7.1 Inspection and Light Hatches a Inspect the hatches for corrosion, paint and coating failures, holes, and cover sealing. X b On loose covers, check for a safety chain in good condition. X c On light hatches over 30 in. across, check for safety rods. X d Inspect the condition of the gaskets on bold or latched down hatch covers. X

C.2.7.2 Staging Support Connection

Inspect the condition of the staging support for corrosion. N/A

C.2.7.3 Breathers and Vents a Inspect and service the breather. X b Inspect screens on vents and breathers. X

C.2.7.4 Emergency P/V Hatches a Inspect and service pressure/vacuum hatches. (Setting should be high enough to prevent chattering of breather during normal operation. See breather manufacturer’s guide.)

N/A b Inspect liquid seal hatches for corrosion and proper liquid level in the seal. N/A

C.2.7.5 Sample Hatch a Inspect sample hatch for corrosion. X b Check that the cover operates properly. X c If the tank has no gauge well, check for a hold-off distance marker and check measurement. X

C.2.8 Floating Roof

C.2.8.1 Roof Deck a Hammer test the area between roof rim and shell. (If access for hammer testing is inadequate, measure the distance from the bottom edge of the roof to the corroded area and then hammer test from inside the pontoon.)

N/A b In sour water service, clean and test all deck plate weld seams for cracking unless the lower laps have been seal-welded.

N/A c Check that either the roof drain is open or the drain plug in the roof is open in case of unexpected rain.

N/A d On flat bottomed and cone bottom roof decks, check for a vapor dam around the periphery of the roof. The dam should be continuous without break to prevent escape of vapors to the seal area from under the center of the roof.

N/A

C.2.8.2 Floating Roof Pontoons a Visually inspect each pontoon for liquid leakage. N/A

Tank Out-of-Service Inspection Checklist Continued

Item Completed

X b Run a light wire through the gooseneck vents on locked down inspection hatch covers to make sure they are open.

N/A c Inspect lockdown latches on each cover. N/A d Check and report if each pontoon is: N/A

1) vapor tight (bulkhead seal welded on one side on bottom, sides, and top), N/A

2) liquid tight (seal-welded on bottom and sides only), or N/A

3) Unacceptable (minimum acceptable condition is liquid tight). N/A

C.2.8.3 Floating Roof Cutouts a Inspect underside of cutouts for mechanical damage. N/A b Inspect welds for cracks. N/A c Inspect plate for thinning, pitting, and erosion. N/A d Measure mixer cutouts and record plate thickness for future mixer installation or replacement. N/A

Plate thickness ______ .

C.2.8.4 Floating Roof Supports a Inspect fixed low and removable high floating roof legs for thinning. X b Inspect for notching at bottom of legs for drainage. X c Inspect for leg buckling or felling at bottom. X d Inspect pin hole in roof guide for tears. X e Check plumb of all legs. X f Inspect for adequate reinforcing gussets on all legs through a single portion of the roof. X g Inspect the area around the roof legs for cracking if there is no internal reinforcing pad or if the topside pad is not welded to the deck plate on the underside.

X h Inspect the sealing system on the two-position legs and the vapor plugs in the fixed low leg for deterioration of the gaskets.

X i On shell-mounted roof supports, check for adequate clearance based on the maximum floating roof movement as determined by the position of the roof relative to the gauge well and/or counter-rotational device.

X

C.2.9 Floating Roof Seal Assemblies

C.2.9.1 Primary Shoe Assembly a Remove four sections of foam log (foam-filled seals) for inspection on 90° locations. N/A b Inspect hanger attachment to roof rim for thinning, bending, broken welds, and wear of pin holes. N/A c Inspect clips welded to roof rim for thinning. N/A d Shoes—inspect for thinning and holes in shoes. N/A e Inspect for bit-metal bolts, clips, and attachments. N/A f Seal fabric—inspect for deterioration, stiffening, holes, and tears in fabric. N/A g Measure length of fabric from top of shoe to roof rim, and check against maximum anticipated annular space as roof operates.

N/A h Inspect any modification of shoes over shell nozzles, mixers, etc., for clearance. N/A i Inspect shoes for damage caused by striking shell nozzles, mixers, etc. N/A

Tank Out-of-Service Inspection Checklist Continued

Item Completed

C.2.9.2 Primary Toroidal Assembly a Inspect seal fabric for wear, deterioration, holes, and tears. N/A b Inspect hold-down system for buckling or bending. N/A c Inspect foam for liquid absorption and deterioration. N/A

C.2.9.3 Rim-Mounted Secondaries a Inspect the rim-mounted bolting bar for corrosion and broken welds. N/A b Measure and chart seal-to-shell gaps. N/A c Visually inspect seam from below, looking for holes as evidenced by light. N/A d Inspect fabric for deterioration and stiffness. N/A e Inspect for mechanical damage, corrosion, and wear on tip in contact with shell. N/A f Inspect for contact with obstructions above top of shell. N/A

C.2.10 Floating Roof Appurtenances

C.2.10.1 Roof Manways a Inspect walls of manways for pitting and thinning. X b On tanks with interface autogauges, check seal around gauge tape cable and guide wires through manway cover.

X c Inspect cover gasket and bolts. X

C.2.10.2 Rim Vent a Check rim vent for pitting and holes. X b Check vent for condition of screen. X c On floating roof tanks where the environmental rules require closing off the vent, check the vent pipe for corrosion at the pipe-to-rim joint and check that the blinding is adequate.

X

C.2.10.3 Vacuum Breaker, Breather Type a Service and check operation of breather valve. X b Check that nozzle pipe projects no more than 1/2 in. below roof deck. N/A

C.2.10.4 Vacuum Breaker, Mechanical Type

Inspect the stem for thinning. Measure how far the vacuum breaker cover is raised off the pipe when the roof is resting on high or low legs.

N/A a On high legs: _________ . N/A b On low legs: _________ . N/A

C.2.10.5 Roof Drains: Open Systems, Including Emergency Drains a Check liquid level inside open roof drains for adequate freeboard. Report if there is insufficient distance between liquid level and top of drain.

N/A b If tank comes under Air Quality Monitoring District rules, inspect the roof drain vapor plug. N/A c If emergency drain is not at the center of the roof, check that there are at least three emergency drains.

C.2.10.6 Closed Drain Systems: Drain Basins a Inspect for thinning and pitting. N/A b Inspect protective coating (topside). N/A c Inspect basin cover or screen for corrosion. N/A

Tank Out-of-Service Inspection Checklist Continued

Item Completed

X d Test operation of check valve. N/A e Check for presence of check valve where bottom of basin is below product level. N/A f Inspect drain basin(s) to roof deck welds for cracking. N/A g Check drain basin(s) outlet pipe for adequate reinforcement to roof deck (including reinforcing pad).

N/A

C.2.10.7 Closed Drain Systems: Fixed Drain Line on Tank Bottom a Hammer test fixed drain line on tank bottom for thinning and scale/debris plugging. N/A b Inspect supports and reinforcing pads for weld failures and corrosion. X c Check that pipe is guided, not rigidly locked to support, to avoid tearing of tank bottom plate. X

C.2.10.8 Closed Drain Systems: Flexible Pipe Drain a Inspect for damage to exterior of pipe. N/A b Check for obstructions that pipe could catch on. N/A c Inspect shields to protect pipe from snagging. N/A d Inspect results of hydrostatic test on flexible roof drain system. N/A

C.2.10.9 Closed Drain Systems: Articulated Joint Drain a Hammer test rigid pipe in flexible joint systems for thinning and scale/debris plugging. N/A b Inspect system for signs of bending or strain. N/A c Inspect results of system hydrostatic test. N/A d Inspect landing leg and pad. N/A

C.2.10.10 Autogauge System and Alarms a Check freedom of movement of tape through autogauge tape guide. X b Inspect sheaves for freedom of movement. X c Test operation checker. X d Inspect tape and tape cable for twisting and fraying. X e Test the tape’s freedom of movement through guide sheaves and tape guide pipe. X f On open-top tanks, check that gate tapes with cables have no more than one foot of tape exposed with float at lowest point.

X g Check float for leakage. X h Test float guide wire anchors for spring action by pulling on wire and releasing. N/A i Inspect float wells in floating roofs for thinning and pitting of walls just above the liquid level. X j Check that the autogauge tape is firmly attached to the float. X k Inspect the tape cable and float guide wire fabric seals through the float well cover. N/A l Inspect the bottom guide wire attachment clip: inspect for a temporary weighted bar instead of a permanent welded down clip.

X m Inspect board-type autogauge indicators for legibility and freedom of movement of indicator. X n Measure and record these distances to determine if seal damage will occur if tank is run over from: X

1) Shell top angle to underside of tape guide system. X

2) Liquid level on floating top to top of secondary seal. X o Identify floating roofs where the tape is connected directly to the roof. X p Overfill alarm: Inspect tank overfill prevention alarm switches for proper operation. X

Tank Out-of-Service Inspection Checklist Continued

Item Completed

X

C.2.11 Common Tank Appurtenances

C.2.11.1 Gauge Well a Inspect gate well pipe for thinning at about two-thirds distance above the bottom: look for thinning at the edge of the slots.

X b Check for corrosion on the pipe joint. Check that sample cords, weights, thermometers, etc., have been removed from the pipe.

X c Check for cone at bottom end of pipe about one foot above the bottom. X d Check condition of well washer pipe and that its flared end is directed at the near side of the hold off pad.

X e Check that supports for gauge well are welded to pad or to shell and not directly to bottom plate. X f Check operation of gauge well cover. X g Check presence of a hold-off distance marker in well pipe and record hold-off distance. X

Hold-off distance _________ .

h Identify and report size and pipe schedule, and whether pipe is solid or slotted. Report slot size. X i Check that the hold-off distance plate is seal-welded to the bottom and that any gauge well supports are welded to the plate and not directly to the bottom.

X j Inspect vapor control float and cable. X k Check for presence and condition of gauge well washer. X l Check for bull plug or plate blind on gauge well washer valve. X m Inspect gauge well guide in floating roof for pitting and thinning. X n Inspect the guide rollers and sliding plates for freedom of movement. X o Inspect condition of gauge well pipe seal system. X p On black oil and diesel services: if gauge well is also used for sampling, check for presence of a thief- and gauge-type hatch to avoid spillage.

q Visually inspect inside of pipe for pipe weld protrusions which could catch or damage vapor control float.

X

C.2.11.2 Sampling Systems: Roof Sample Hatches a Inspect roof-mounted sample hatches for reinforcing pads and cracking. X b Inspect cover for operation. X c For tanks complying with Air Quality Monitoring District rules, inspect sample hatch covers for adequate sealing.

X d Check horizontal alignment of internal floating roof sample hatches under fixed roof hatches. X e Inspect the sealing system on the internal floating roof sample hatch cover. X f Inspect floating roof sample hatch cover recoil reel and rope. N/A

C.2.11.3 Shell Nozzles a Inspect shell nozzles for thinning and pitting. X b Inspect hot tap nozzles for trimming of holes. X c Identify type of shell nozzles. X d Identify and describe internal piping, including elbow-up and elbow-down types. X

Completed

X

C.2.11.4 For Nozzles Extended Into the Tank a Inspect pipe support pads welded to tank bottom. X b Inspect to see that pipe is free to move along support without strain or tearing action on bottom plate.

X c Inspect nozzle valves for packing leaks and damaged flange faces. X d Inspect heater stream nozzle flanges and valves for wire cutting. N/A e Report which nozzles have thermal pressure relief bosses and valves. X f In internal elbow-down fill line nozzles, inspect the wear plate on the tank bottom. X g On elbow-up fill lines in floating roof tanks, check that opening is directed against underside of roof, not against vapor space. Inspect impact are for erosion.

X

C.2.11.5 Diffusers and Air Rolling Systems a Inspect diffuser pipe for erosion and thinning. X b Check holes in diffuser for excessive wear and enlargement. X c Inspect diffuser supports for damage and corrosion. X d Check that diffuser supports restrain, not anchor, longitudinal line movement. X e Inspect air spiders on bottom of lube oil tanks for plugging and damaged or broken threaded joints.

C.2.11.6 Swing Lines a Inspect flexible joint for cracks and leaks. N/A b Scribe the flexible joint across the two moving faces and raise end of swing line to check the joint’s freedom of movement, indicated by separation of scribe marks.

N/A c Check that flexible joints over 6 in. are supported. N/A d Inspect the swing pipe for deep pitting and weld corrosion. N/A e Loosen the vent plugs in the pontoons and listen for a vacuum. Lack of a vacuum indicates a leaking pontoon.

N/A f Check the results of air test on pontoons during repairs. N/A g Inspect the pontoons for pitting. N/A h Inspect the pull-down cable connections to the swing. N/A i Inspect the condition of the bottom-mounted support, fixed roof limiting bumper, or shell-mounted limiting bumper for wood condition, weld and bolt corrosion, and seal welding to bottom or shell.

N/A j Inspect safety hold-down chain for corrosion and weak links. N/A k Check that there is a welded reinforcing pad where the chain connects to the bottom. N/A l

If the floating swing in a floating or internal floating roof tank does not have a limiting device preventing the swing from exceeding 60…