Attachment J.2 - DOV-FY20-FAC 757-Tank 757-FINAL.pdf

US Army Corps of Engineers Omaha District

API 653 In-Service Inspection Report

Dover Air Force Base, Delaware Tank Facility 757

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

USACE POL-MCX

29 January 2020

API 653 In-Service Inspection Report Dover AFB, Delaware

Table of Contents

ACRONYMS AND ABBREVIATIONS

EXECUTIVE SUMMARY AND SUITABILITY FOR CONTINUED SERVICE

THIS INSPECTION

PREVIOUS INSPECTION DATES

STATE REGULATIONS

RECOMMENDED FUTURE INSPECTION DATES

A. GENERAL PROJECT INFORMATION

1. SPCC Mandated AST Inspections

2. Site Information

3. Previous Inspection and Repairs

4. Future Projects

B. TANK INSPECTION COMMENTS

1. Tank Construction

2. Tank Foundation

3. Tank Bottom

4. Tank Roof

5. Tank Shell

6. Tank Appurtenances

7. Tank Coating

8. Tank Piping System

9. Fire Protection System

10. Secondary Containment

11. Cathodic Protection

GENERAL TANK INFORMATION

C. FINDINGS AND RECOMMENDATIONS

1. MANDATORY REPAIRS per API 653, NFPA, or CFRs

2. SHORT TERM RECOMMENDATIONS

APPENDIX ‘A’: ENGINEERING CALCULATIONS AND DRAWINGS

SHELL THICKNESS CALCULATIONS

SHELL AND ROOF ULTRASONIC THICKNESS MEASUREMENTS

SHELL SETTLEMENT ANALYSIS

TANK DRAWINGS

OSHA ACCESS STRUCTURE REPORT

APPENDIX ‘B’: API 653 CHECKLISTS FOR TANK INSPECTIONS

APPENDIX ‘C’: PHOTOGRAPHS

ACRONYMS AND ABBREVIATIONS

API American Petroleum Institute

AFFF Aqueous Film Forming Foam

ASME American Society of Mechanical Engineers

ASNT American Society of Non-Destructive Testing

ATG Automatic Tank Gauge

BBL Barrel

CC Carbon Steel

CFR Code of Federal Regulations

CP Cathodic Protection

CS Carbon Steel

DFT Dry Film Thickness

FAC Facility

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

NA Not Applicable

NACE National Association of Corrosion Engineers

NDT Non-Destructive Testing

NFPA National Fire Protection Association

PSI Pounds per Square Inch

PT Penetrant Testing

PTFE Polytetrafluoroethylene (e.g., TEFLON)

P/V Pressure/Vacuum

PST Product Saver Tank

SS Stainless Steel

TRV Thermal Relief Valve

UFC Unified Facilities Criteria

UFGS Unified Facilities Guide Specifications

UG Underground

UT Ultrasonic Testing

EXECUTIVE SUMMARY AND SUITABILITY FOR CONTINUED SERVICE

Austin Brockenbrough & Associates, LLC (Brockenbrough) was retained by Omaha District USACE under Contract

No. W9128F-17-D-0017 Delivery Order W9128F20F0024 to perform SPCC Mandated AST/UST Inspections at various locations. As required by this task, Brockenbrough executed a tank inspection site visit to Dover Air Force

Base, Dover, Delaware. An API 653 In-service (visual external) Inspection was conducted for Facility No. 757, on

January 29, 2020. This inspection was performed in accordance with API Standard 653, “Tank Inspection, Repair, Alteration, and Reconstruction,” and the referenced contract. The inspection included a tank foundation settlement evaluation and UT inspection of the shell and roof. All observations made during this in-service (visual external) inspection were made from the exterior of the tank.

Facility 757 is a 43-foot 6-inch diameter by 42-foot 3-inch tall, single wall, vertical, field-erected tank with a nominal storage capacity of 11,180 barrels (per dataplate) of Jet A (F-24). The tank erector’s nameplate indicates the tank was erected in accordance with API 653 in 1997. A repair organization’s nameplate indicates stilling wells for the ATG, manual gauging well, and water probe were installed in 2017, and that modifications to the water draw off system and other miscellaneous repairs were also made at that time. Photographs included in a February

2015 out-of-service inspection, indicate the liner was placed over the dike area sometime after that inspection.

Details of tank construction and appurtenances are included in the Tank Information Table in Section ‘B’.

This tank was found to be in generally good condition, fully serviceable, no mandatory repairs noted, and suitable for continued service. Additional noted deficiencies are discussed in more detail in Section ‘C’ and should be addressed in a timely manner. Photographs of the tank are included in Appendix ‘C’.

Delaware aboveground storage tank regulations require in-service and out-of-service inspections to be performed at intervals in accordance with API 653. The next API In-service (external) inspection of Tank 757 should be performed by January 2025. The February 2015 out-of-service inspection report recommended an internal inspection to be performed by February 2025. The inspection should include an examination of the tank bottom by magnetic flux leakage (MFL or MFE) technology and a thorough code compliance evaluation. However, it may be advantageous to schedule the external and internal inspections concurrently.

THIS INSPECTION

API In-Service (External) Inspection Date: 29 January 2020

Equipment Used:

Shell Settlement Survey Equipment

Rotary Laser Level: CST/berger Model: ALHV Calibrated: Self -leveling

Ultrasonic Thickness Gauge

Manufacturer: NDT Systems Model Number: Nova TG110-DL Probe: 560P (Thru-paint) Calibration Method: Calibration Block NDT Technician (s): Mike O’Connor

Inspector(s): Mike O’Connor

PREVIOUS INSPECTION DATES

API Out-of-Service (Internal) Inspection Date: February 2015 API In-Service (External) Inspection Date: NA

STATE REGULATIONS

State Regulation for API In-Service Tank Inspections January 2025 State Regulation for API Out-of-Service Tank Inspections February 2025

RECOMMENDED FUTURE INSPECTION DATES

API Out-of-Service (Internal) Inspection Date: February 2025 API Ultrasonic Thickness Inspection of Shell Date: January 2035 API In-Service (External) Inspection Date: January 2025

Mike O’Connor Mechanical Designer API 653 Inspector No. 6230

A. GENERAL PROJECT INFORMATION

1. SPCC Mandated AST Inspections

This project will perform API 653 and STI SP001 inspections of various tanks at facilities throughout the United States. The specific inspection performed is based on available information on the tank type, product being stored, and recommendations from previous inspection reports (if available). Additional consideration is given to federal, state, and local regulations, as well as applicable military criteria and general industry standards.

For this Task Order, Brockenbrough performed Inspection of Facilities 734, 756, and 757 located at

Dover Air Force Base, Delaware. For the Tank Facility 757, an API 653 In-service (external) Tank

Inspection was performed on January 29, 2019. The inspection included a shell settlement survey and a shell UT inspection.

2. Site Information

Dover Air Force Base is located in Dover, Delaware. The 436th Airlift Wing (AW), a subordinate of

Eighteenth Air Force also known as the "Eagle Wing," is the active duty military host unit for the Base.

Eagle Wing consists of operations, maintenance, mission support and medical groups and has more than 4,000 active-duty military and civilian employees. Dover Air Force Base is also home to the Air

Force Reserve’s 512th Airlift Wing, whose mission is to assist with maintenance and operation of the C-

5M and C-17 aircraft assigned to the 436th AW. The 436th and 512th AWs fly hundreds of missions throughout the world, providing movement of outsized cargo and personnel on scheduled, special assignment, exercise, and contingency airlift missions. Together, they account for 20 percent of the nation's strategic outsized airlift capability and fly to more than 100 countries.

3. Previous Inspection and Repairs

A 2015 out-of-service inspection report indicates the tank was internal inspected in February 2015.

Photographs of the bare secondary containment concrete in that report suggest the secondary containment liner was installed over the concrete after that inspection was performed. The original

Allentech aluminum honeycomb internal floating pan, shown in the 2015 report photos, also appears to have been since replaced with a Petrex aluminum honeycomb internal floating pan. A repair nameplate indicates that in 2017, two 8-inch and one 6-inch stilling wells, for the ATG, manual gauging, and water probe, were added. Facility personnel indicated the 2-inch water draw-off and product return nozzles were also added at that time. The independent (shell mounted) level alarms appear to have also been upgraded as part of the 2017 repairs.

4. Future Projects

Facility personnel report there are currently no projects scheduled for execution in the future that affect the operation of the tank.

B. TANK INSPECTION COMMENTS

1. Tank Construction

Tank Facility 757 is an aboveground, vertical, storage tank, measuring 43 feet 6 inches in diameter and

42 feet and 3 inches tall, and with a nominal capacity of 11,180 BBLs (per data plate). The capacity of the tank from the bottom of shell to the overflow is approximately 9,800 BBLs. The tank manufacturer’s nameplate indicates the tank was constructed to API 653 - 9th Edition in 1997.

2. Tank Foundation

The perimeter of the bottom rests on a 38-inch tall concrete ringwall. The foundation was visually evaluated during the inspection for broken concrete, spalling, cracks, and vegetation against the bottom of the tank. The inspection found approximately 70 feet of vertical hairline cracks in the ringwall. A shell settlement survey was performed during the inspection in accordance with Appendix ‘B’ of API

Standard 653. The shell settlement evaluation indicates the settlement of the bottom of the shell and perimeter of the tank bottom is acceptable.

3. Tank Bottom

The previous inspection reports indicate the cone-down bottom is made of 5/16-inch lap-welded plate.

with 5/16-inch annular plates.

4. Tank Roof

The tank roof is a lap-welded cone roof, constructed out of steel plate. The roof is supported by eight rafters spaced approximately 17 feet apart. API 650 requires the rafters to be spaced no further apart than seven feet at the perimeter. As a result of the extreme rafter spacing, there are areas near the perimeter of the roof showing signs of water ponding. Entry to the internal ladder is gained through a

36-inch round roof hatch. The hatch does not have a rain lip and there is corrosion on the mating surfaces of the flange and cover plate. The round hatch does not provide 30 inches of clearance on the climbing side of the ladder as required by OSHA.

5. Tank Shell

The vertical and cylindrical shell consists of five butt welded courses. The ultrasonic thickness measurements of the shell and calculations included in Appendix ‘A’ indicate the shell has more than 30 years of remaining life. API 653 recommends ultrasonic thickness measurements of the shell be taken at least every 15 years. The exterior of the shell was visually inspected and evaluated for peaking and banding. Little peaking and banding of the butt-welded shell seams were observed. The peaking-and-banding appeared to be within limits allowed by API 650.

6. Tank Appurtenances

a. Gauging

The tank’s Honeywell Enraf ATG is installed through an 8‐inch fully slotted aluminum gauge well.

The manual gauge well/sample hatch is fitted with a floating plug retriever. A Vito water probe is installed through a 6-inch well near the center of the tank. The tank also has a Varec autogauge, which is not consistent with the ATG. Contrary to manufacturer’s instructions, the tape is attached directly to the internal floating pan, which often results in damage to the autogauge and inconsistent level readings.

b. Level Alarms

The tank has shell mounted (independent) high, high-high, low, and low-low level alarms. The tank also has redundant ATG alarms.

c. Stairs and Platforms

The tank’s steel cone roof is accessible by a circumferential stairway mounted on the shell of the tank. The circumferential stairway step rise is generally 9 inches continuously from ground level to the top landing. The width of the stair steps is generally 28 inches. The measured height of the stairway handrail is 32 inches. The 2017 repairs appear to have widened the stairway at the new level alarms.

d. Grounding and Bonding

The tank’s eight grounding cables are welded or brazed to the shell and appeared to be in good condition.

7. Tank Coating

The tank’s coatings were evaluated for deterioration. The exterior of the shell and roof show little sign of significant deterioration. However, there is a considerable amount of bird droppings on the roof and roof guardrails, which could accelerate deterioration.

8. Tank Piping System

Facility 757 is a hydrant system tank. Fuel is primarily received from bulk with backup receipt from a truck off-load station located adjacent to the pumphouse. Fuel is issued to the hydrant system, and various truck fillstands. Except for the aluminum level control valve, all of the fuel system piping inside the dike area is aboveground and stainless steel. There appears to be adequate thermal relief throughout the piping system. However, the receipt piping thermal relief valve is set at 50 psi, which may be less than the receipt pressure and could result in slight but continuous bypass filling and premature failure (washout) of the thermal relief valve.

9. Fire Protection System

There are three fire hydrants within 300 feet of the tank.

10. Secondary Containment

Secondary containment consists of an earthen berm with concrete cover and a flexible membrane liner system covering the concrete on the interior of the berms and the secondary containment basin. The secondary containment was evaluated during the inspection. The lack of expansion joins sealants on the concrete covering the exterior of the dike berms has resulted in the widening of the gaps between sections of concreted due to expansion of freezing water. The containment is of sufficient size to contain a total tank loss plus an additional two feet of freeboard.

11. Cathodic Protection

Impressed current cathodic protection anodes are installed in the sand between the FML liner and the tank bottom. The system is combined with the adjacent tank and there is one common rectifier. The remote monitoring unit (RMU) did not appear to be operating. The analogue indicators on the rectifier indicated the rectifier had normal output voltage and current. The December 2019 annual cathodic protection survey report indicated that, except for the remote monitoring unit, which was not working, the cathodic protection system was working properly and that the remote monitoring units was recommended to be replaced at the next annual survey.

GENERAL TANK INFORMATION

ITEM DESCRIPTION

Owner United States Air Force

Location Dover Air Force Base

Facility Number 757

Tank Number Tank 757

State / Country Delaware / U.S.A.

City Dover

Inspection Date January 29, 2020

Tank Manufacturer Matrix Service

Design Standard API 650 – 9th Edition

Date of Construction 1997 (per nameplate)

Tank Contents Jet A (F-24)

Tank Serial Number EC681

Tank Diameter 43’-6”

Shell Height 42’-3”

Overflow Height 36’-11”

Tank Capacity 11,180 BBL nominal (per nameplate), 9.800 BBL (to overflow), 8,400 BBL (LLA to HLA).

Foundation 38” tall concrete ring wall.

Construction and Material

Bottom Lap-welded carbon steel plate (5/16 per 2015 inspection report).

Shell Five courses of butt-welded carbon steel plate.

Floating Roof Petrex internal Floating Pan.

Fixed Roof Lap welded steel cone roof.

Cathodic Protection Impressed Current.

Interior Coating System Epoxy 100% (assumed)

Exterior Coating System Epoxy/epoxy/polyurethane assumed.

Level Gauging Enraf ATG and water probe, manual gauging well, Varec autogauge (mechanical tape level gauge).

Overfill Protection Independent high and high-high level alarms, ATG (redundant) alarms, float operated high level control valve.

Piping Receipt 8” Welded stainless steel

Issue 12” Welded stainless steel

Low Suction 4” Welded stainless steel

Water Draw-off 2” Welded stainless steel

Level Alarms Shell mounted (independent) high, high-high, low, and low-low level alarms;

ATG (redundant) Alarms.

C. FINDINGS AND RECOMMENDATIONS

Tank Facility 757 was found to be in generally good condition. The tank is fully serviceable, with no mandatory deficiencies that would require immediate removal of the tank from service. However, there were a few minor items observed that could be addressed to reduce long term maintenance, improve operability, and more clearly comply with federal, state, and local regulations or military criteria.

1. MANDATORY REPAIRS per API 653, NFPA, or CFRs

Mandatory repairs represent items that require immediate attention in order to prevent imminent risk to system operators, equipment, or the adjacent environment. The tank would have to be taken out-of-service to complete these repairs. No Mandatory Repairs are required to be performed.

2. SHORT TERM RECOMMENDATIONS

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

Term Repairs that directly relate to the long-term preservation of the asset. Short-term 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. Relocate Overflows

OBSERVATION: One of the four shell overflows is near to over the bottom of the stairs and two of the overflows are near to over the receipt and issue nozzle valves.

REFERENCE: API 650 paragraph H.5.3.3 does not allow overflows to be located over stairways or tank nozzle isolation valves. DoD Standard Design shows only one overflow on a 10,000 bbl tank with an 8-inch receipt nozzle, and that overflow is on the side of the tank opposite the product nozzles and the stairway. API 650 paragraph H.5.2.2.1 also requires peripheral circulation vents be spaced not more than 32 feet apart.

RECOMMENDATION: Raise the existing shell overflows, currently located near to over the bottom of the stairway, and tank nozzles repair the shell at that those locations and provide similar sized shell vents above the old locations of the demolished overflows. Provide a shell overflow at the location farthest away from the shell product nozzles and not above stairway. Verify the overflows are sufficient to handle the maximum possible receipt rate.

Overflow

Overflow

Provide additional overflow in this area or expand existing.

b. Reinstall and Recalibrate Autogauge

OBSERVATION: The Varec autogauge tape is connected directly to the floating pan. Constant readjustment of the autogauge is necessary.

REFERENCE: Guidance for new construction, provided in UFC 3-460-01, Table 8-1, Item o, and DoD

Standard Design AW 78-24-27 (2015), includes a mechanical tape level gauge (autogauge).

Manufacturers of mechanical tape level gauges (Varec and Shand and Jurs) recommend attaching the tape to a float in a floating pan penetration well or to a weight resting on top of the pan, but not directly to the pan to avoid damage to the tape or gauge head in the event the pan does not descend smoothly with the fuel, which is a consistent problem with smaller tanks. UFC 3-460-03, Section 8-

9.8.1.1 requires mechanically operated tape gauges to be checked regularly in order to verify accuracy. If the tape is not accurate, UFC 3-460-03 requires calibration.

RECOMMENDATION: Reinstall the autogauge by attaching the tape to a weight resting on top of the pan in accordance with manufacturer’s recommendations and calibrate the autogauge to agree with the Enraf ATG and manual gauging.

c. Provide Valves and Support

OBSERVATION: There is a double-curved (offset) spool piece between the receipt shell nozzle and the isolation valve. The thermal relief piping is connected to the spool piece. There is no isolation valve near to and upstream of the level control valve. The level control valve is made of aluminum.

The piping between the nearest pipe support and the tank includes two ball joints, two spool pieces, a level control valve, a DBB valve, and is not properly supported; as a result, those components and the shell of the tank may be considerably stressed.

REFERENCE: NFPA 30 paragraph 22.13.1 requires tank isolation valves to be located as close to the tank shell as practical. Guidance for new construction, provided in DoD Standard Design AW 78-24-

27, includes tank isolation valves mounted directly on the shell nozzles and the thermal relief piping connected to a dedicated shell nozzle. UFC 3-460-01, paragraph 12-9 and DoD Standard

Design AW 78-24-27 also include an isolation valve near to and upstream of the level control valve.

Guidance for new construction, provided in UFC 3-460-01, paragraph 9-2.1. e) and DoD Standard

Design AW 78-24-27, includes thermal relief around all isolation valves. NFPA 30 paragraph 27.4.3 and UFC 3-460-01, paragraph 3-6.7.1 prohibit valves made of aluminum and other low melting point materials. Guidance for construction of fuel system piping, provided in UFC 3-460-01, paragraph 15-11.5, includes diaphragm control valves made of stainless steel or internally chrome plated steel or internally nickel-plated nodular iron and prohibits aluminum valves. Guidance for new construction, provided in DoD Standard Design AW 78-24-27, includes a pipe support that is mounted on an extension of the tank foundation and located between the level control valve and an upstream isolation valve, which works with the ball joints to eliminate stress on the tank shell.

RECOMMENDATION: Relocate the receipt isolation valve to the shell nozzle. Provide a dedicated shell nozzle for the receipt TRV discharge piping. Provide an isolation valve adjacent to and upstream of the level control valve. Provide receipt thermal relief piping and valves with set-pressures 10 percent above the deadhead pressure of the receipt pump around the isolation valves. Replace the aluminum level control valve with a stainless steel or internally chrome plated steel or internally nickel plated nodular iron level control valve. It should be noted that a steel valve is going to be much heavier than an aluminum valve. And, as there is no foundation extension and it is not practical to add one to support the receipt piping, provide a spring loaded pipe support between the level control valve and the recommended upstream isolation valve, or since tank settlement has long since stabilized and the ball joints are unnecessary for flexibility in this case, eliminate the ball joints in the receipt piping all together, to relieve the stress on the shell and the valves.

d. Provide Issue Pipe Support

OBSERVATION: The piping between the nearest pipe support and the tank issue nozzle includes two ball joints, a double curved (offset) spool piece, a DBB valve, and is not properly supported; as a result, those components and the shell of the tank may be considerably stressed.

REFERENCE: Guidance for new construction, provided in DoD Standard Design AW 78-24-27, includes a pipe support that is mounted on an extension of the tank foundation that works with the ball joints to eliminate stress on the tank shell.

RECOMMENDATION: As it is not practical to add a foundation extension, provide a spring loaded pipe support near the issue isolation valve, or since tank settlement has long since stabilized and the piping configuration is flexibility, eliminate the ball joints in the issue piping all together.

e. Provide Davits

OBSERVATION: The two 36-inch shell manhole covers are hinged. Hinged covers tend to bind and interfere with proper gasket sealing. In addition, failure of the hinge pins hasps may result in injury to personnel.

REFERENCE: Guidance for new construction, provided in UFC 3-460-01, Table 8-1 Item f) and DoD

Standard Design AW 78-24-27, includes 36-inch shell manholes with cover davits.

RECOMMENDATION: Replace the shell manhole cover hinges with davits to support the shell manhole covers.

f. Provide OSHA Compliant Internal Ladder Access Hatch

OBSERVATION: The 36-inch internal ladder access manhole provides approximately only 28 inches of clearance on the climbing side of the ladder. The cover is not bolted and does not have a rain lip.

REFERENCE: OSHA regulation 29 CFR 1910.23 (d) (June 2018) requires 30 inches of clearance (24 inches with a deflector plate) on the climbing side of a ladder including at access hatches. Guidance for new construction, provided in DoD design Standard AW 78-24-27, includes an OSHA compliant internal ladder access hatch with a rain lip.

RECOMMENDATION: Remove the unused well from the internal ladder and provide an OSHA

g. Modify the Roof Support Structure

OBSERVATION: The rafters are spaced every 22 1/2 degrees, approximately 17 feet apart at the perimeter of the roof. At this time, the tank’s steel, lap welded, cone roof shows only minor sign of water ponding around the perimeter. However, this is expected to worsen over time.

REFERENCE: As early as 1996, API 650 required rafter spacing at the perimeter of the tank roof to be no greater than 75 inches apart. Earlier API requirements may have been more stringent. Later editions of API 650, paragraph 5.10.4.4 increased the maximum allowable spacing to 84 inches.

RECOMMENDATION: Modify the roof support structure to eliminate the water ponding and bring the roof rafter spacing into compliance with API 650.

Photo from Cape’s 2015 Internal Inspection

3. LONG-TERM RECOMMENDATIONS

RECOMMENDED REPAIRS as Part of Regular Maintenance Long-term Repairs that directly relate to repair/upgrade of an asset to bring it up to the current standard from the standard at time of construction. Long-term 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.

a. Repair Concrete

OBSERVATION: There are approximately 70 feet of radial and vertical hairline cracks in the ringwall foundation. If precipitation enters the foundation through the cracks, the water could promote corrosion of the reinforcing steel in the concrete, especially if it expanded upon freezing.

Deterioration of the foundation could lead to inadequate support for the tank and loss of secondary containment.

REFERENCE: API 650 paragraph 5.3.1 and API 653 Appendix ‘B’ require foundations to provide adequate support. NFPA 30 paragraph 22.11.2.4 and 40 CFR 112.7(c)(1) require secondary containment to be liquid tight.

RECOMMENDATION: Seal approximately 70 linear feet of cracks in the tank foundation ringwall.

b. Repair Coating

OBSERVATION: There are bird droppings on the roof and roof perimeter guardrails. There is corrosion on the roof manhole flange and cover and roof perimeter vent/inspection hatch hinges.

There is scattered isolated coating failures and corrosion on stairway tread and top platform deck.

REFERENCE: Guidance for new construction, provided in UFC 3-460-01, paragraph 8-3.10, includes coating the exterior. UFC 3-460-01, Appendix F (Monthly Tank Inspection Checklists) requires

Facility personnel to inspect for evidence of corrosion. API 571, paragraph 4.3.2.3.h) reads, “bird turds can also cause accelerated corrosion and unsightly stains.”

RECOMMENDATION: Add regular power washing of the exterior of the roof and lower shell to the regular maintenance schedule. Power wash the exterior of the roof. Provide spot repairs to the coatings on the roof, roof manhole flange and cover, the stairway tread, and top platform

(approximately 100 square feet).

c. Replace Remote Monitoring Unit (RMU)

OBSERVATION: The 2019 CP Survey recommended replacing the cathodic protection rectifier’s remote monitoring unit (RMU) during the next CP survey. The RMU did not appear to be operable during the inspection. The RMU is supposed to provide a continuous readout of the cathodic protection current and voltage in the operators building and the POL office.

REFERENCE: Guidance for new construction, provided in UFC 3-460-and UFC 3-460-01, includes cathodic protection for aboveground storage tanks bottoms. Guidance for maintenance of cathodic protection systems, provided in UFC 30-460-03, paragraph 9-2.2.1, includes inspection of cathodic protection systems by the operator to verify operation at least every two months.

RECOMMENDATION: If the cathodic protection rectifier RMU is not replaced on another contract, replace the cathodic protection rectifier RMU.

d. Repair Roof Inspection Hatch Latches

OBSERVATION: Two of the roof perimeter vent/inspection hatch rotating hasp latch posts are inoperable, which prevented opening those inspection hatches to perform inspection of the IFR.

REFERENCE: API 653, Appendix ‘C’ (Checklist for Out of -service Inspection) item C.1.4.4 includes measuring the level of the internal floating roof (IFR) at several locations to aid in revealing any problems with the IFR. UFC 3-460-03, section 8-9.1.1 requires the facility to occasionally visually inspect the IFR for damage.

RECOMMENDATION: Return the roof perimeter vent inspection hatch latches to operable condition.

e. Provide Expansion Joint Seals

OBSERVATION: The lack of concrete expansion joint seals on the concrete covered dike berms on the outside surface of the dike berms have resulted in plants growing in the joints and water filling the gaps in winter, expanding on freezing and widening the gaps. This may result in eventual collapse of the dike berms.

REFERENCE: NFPA 30 paragraph 22.11.2.4 and 40 CFR 112.7(c)(1) require dikes to be liquid tight.

RECOMMENDATION: Provide expansion joint sealant on the on the outside surface of the dike berms.

f. Remove Old Fuel Stain from Manhole Cover

OBSERVATION: There is fuel stain on the lower manhole cover around the bolting, which indicates prior weeping of the fuel through the manhole gasket.

REFERENCE: UFC 3-460-03 requires the Facility to occasionally check for evidence of leaks.

RECOMMENDATION: Remove the fuel stain and dirt from the shell manhole cover so that the cover may be inspected for active leaks.

g. Modify Secondary Containment or Re-rout Piping

OBSERVATION: The secondary containment liner covered basin is sloped toward the tank on the southwest and under the piping on the east, to a dike drain sump located approximately 40 feet from the tank and 20 feet from the piping on the northeast side. The shell nozzles are on the northwest and northeast sides of the tank. The piping is routed over the north swale.

REFERENCE: NFPA 30 requires secondary containment to be sloped away from the tank for 50 feet or to the dike wall, whichever is less, and away from product piping for a distance of 50 feet.

RECOMMENDATION: Modify the secondary containment to slope way from the tank and the piping per NFPA 30.

Swale

Dike Drain Dike Drain

Piping

APPENDIX ‘A’: ENGINEERING CALCULATIONS AND DRAWINGS

SHELL THICKNESS CALCULATIONS

Job No.: 19-091.03

Job Title: SPCC Tank Inspections - Dover AFB

Subject: Tank Facility 757

By: Mike O'Connor Date: 3/6/20

API-12C

API 653

SHELL CALCULATIONS

Diameter 43.5 feet Wind Velocity 125 mph

Shell Height 42.25 feet

Freeboard 5.16 feet Nom Shell Thk 0.250

Design Fill Height 37.09 feet

Specific Gravity 0.84 API 650 Maximum height of unstiffened shell: 60.2 feet

0.84 API 653

Joint Efficiency 1.00 API 650

Material A36 Mod

Yield Strength 36,000 psi (assumed)

Tensile Strength 58,000 psi (assumed)

Original Design Corrosion Allowance

0.062 in

Required thickness

Lower Upper

Two

CoursesCourses

Allowable Stress 24882 27376

Height Product Required Thickness

Course (feet) Depth 1/4" min

5 10.19 5.07

4 8.02 13.09

3 8.00 21.09

2 8.00 29.09

1 8.00 37.09 min 2020 Corrosion Estimated UTM Visual current net 1997 Rate Service Life Inspection Inspection

Course UTM* thick Thickness * in/yr yrs. Interval Interval

5 0.251 0.251 0.280 0.001 >30 15 5

4 0.259 0.259 0.280 0.001 >30 15 5

3 0.260 0.260 0.280 0.001 >30 15 5

2 0.244 0.244 0.280 0.002 >30 15 5

1 0.301 0.301 0.343 0.002 >30 15 5

* The original thicknesses are assumed based on required design thicknessess, overtolerance and the range of the UTMs.

P.O. Box 4800 4800 W. Hundred Road Chester, Virginia 23831 Phone: 804-748-8746 Fax: 804-748-7849 www.brockenbrough.com

(psi)

2.6(H-1)D

API-650

Original

Hydro

2485723200

API-653

Original

Design

0.100

0.100

2.6HDG

SESESE

0.210

0.177

0.019

0.055

0.138

0.107

2.6(H-1)DG

0.091

0.079

0.128

0.164

0.144

0.112

0.100

SHELL AND ROOF ULTRASONIC THICKNESS MEASUREMENTS

Job No.: 19-091.03

Job Title: SPCC Tank Inspections - Dover AFB

Subject: Tank Facility 757

By: Mike O'Connor Date: 3/6/20

SHELL UTM DATA (0.001 inches)

1 3

2 4

Typical Shell Plate UTMs.

1 2 3 4

1-1 309 311 323 323

1-2 329 329 324 323

1-3a 314 315 315 315

1-3b 321 320 316 315

1-4 310 308 304 301

UTMs Taken From Stairway

1-1 313 314 313

2-3 244 250 248

3-3 261 264 260

4-1 261 264 259

5-1 254 255 251

Roof UTMs

253 253 255 254 258 249 249 289

251 250 249 250 249 250

P.O. Box 4800 4800 W. Hundred Road Chester, Virginia 23831 Phone: 804-748-8746 Fax: 804-748-7849 www.brockenbrough.com

SHELL SETTLEMENT ANALYSIS

Austin Brockenbrough & Associates, L.L.P. Job No. 19-91.03

Location: Dover AFB Date: 3/6/2020

Subject: Tank 757 - Shell Settlement Evaluation By: Mike O'Connor

API 653 Appendix B

Optimum cosine curve, B 2.2.4.e) Z = a + b x cos(theta + c)

Diameter (D) = 43.5 (ft)

Number of equally spaced data points (ft)= 8

L = Arc length between measurement points (ft) = 17.08

Tank Height (H) = 42.25 (ft)

Relative elevation of bottom of shell. (ft)

* Z U S

0 98.542 0.00 0.00 0.00 0.00

1 98.542 0.00 0.00 0.00 0.01

2 98.568 0.03 0.01 -0.01 -0.01

3 98.568 0.03 0.02 0.00 0.01

4 98.583 0.04 0.03 -0.01 -0.02

5 98.552 0.01 0.02 0.01 0.01

6 98.542 0.00 0.01 0.01 0.01

7 98.542 0.00 0.00 0.00 0.00

8 98.542 0.00 0.00 0.00 0.00

Maximum out-of-plane deflection = 0.02

* = measured elevation

*HI (Height of Instrument)

Z = calculated ridged body tilt (in)

U = out-of-plane settlement =

S = out-of-plane deflection z-y

Y = yield sterength of shell material (PSI) = 36,000 (A 36)

E = Youngs modulas of elasticity (lbf/in2) = 29*10^6

S allowable (in) (API 653 B.3.2.1) = (L^2*Y*11)/(2EH) = 0.05 ft

R^2 = (Syy - SSE) / Syy = 0.64 not >=0.9 therefore cosine curve is invalid.

Evaluation by the Arc Length Method described in API 653 B.2.2.5.1 is required.

Austin Brockenbrough & Associates, L.L.P. Job No. 19-91.03

Location: Dover AFB Date: 3/6/2020

Subject: Tank 757 - Shell Settlement Evaluation By: Mike O'Connor

API 653 B.2.2.5.1 Evaluation by Settlement Arc Length Method

* Open top (yes/no) = no Per B.3.2.2, K = 10.5

Settlement arc length (ft), Sarc

Out of plate settlement at Point i (Si)

Allowable settlement at point i (Smax) = MIN[K*Sarc*(D/H)*(Y/E), 4]

Point Sarc (ft) Si (ft) Smax (ft)

3 34.2 0.008 0.04 OK

6 102.5 0.036 0.11 OKSi < Smax →

Evaluation of the settlement by the arc length method indicates the settlement is within acceptable limits.

Si < Smax →

-0.01

0.00

0.01

0.02

0.03

0.04

0.05

0 2 4 6 8 10

Si3 Si6 Measured Elevation (ft)

TANK DRAWINGS

TYN - 757

TANK 757 SHELL LAYOUT

AutoCAD SHX Text

TYNDALL AIR FORCE BASE / USAF

AutoCAD SHX Text 2/21/20

AutoCAD SHX Text 19-091.03

AutoCAD SHX Text

DRAWING TITLE:

AutoCAD SHX Text

PROJECT:

AutoCAD SHX Text

OWNER/CLIENT:

AutoCAD SHX Text

DRAWN BY:

AutoCAD SHX Text

DATE:

AutoCAD SHX Text

JOB N0:

AutoCAD SHX Text

SKETCH NO:

AutoCAD SHX Text

JMD

AutoCAD SHX Text

TYN-757

AutoCAD SHX Text

SPCC MANDATED SHOP-BUILT AST INSPECTIONS

AutoCAD SHX Text

SCALE:

AutoCAD SHX Text

NONE

AutoCAD SHX Text

8" RECEIPT

AutoCAD SHX Text A

AutoCAD SHX Text

36" MANHOLE

AutoCAD SHX Text B

AutoCAD SHX Text

4" LOW SUCTION

AutoCAD SHX Text C

AutoCAD SHX Text

8" ISSUE

AutoCAD SHX Text D

AutoCAD SHX Text

2" WATER DRAW-OFF

AutoCAD SHX Text E

AutoCAD SHX Text

2" PRODUCT RETURN

AutoCAD SHX Text F

AutoCAD SHX Text

1" LOW LEVEL ALARM

AutoCAD SHX Text G

AutoCAD SHX Text

SHELL VENT

AutoCAD SHX Text K

AutoCAD SHX Text M

AutoCAD SHX Text

GROUNDING ROD

AutoCAD SHX Text N

AutoCAD SHX Text

ANCHOR CHAIR

AutoCAD SHX Text

36" UPPER MANHOLE

AutoCAD SHX Text H

AutoCAD SHX Text

HIGH LEVEL ALARM

AutoCAD SHX Text I

AutoCAD SHX Text

OVERFLOW

AutoCAD SHX Text J

AutoCAD SHX Text 1-4

AutoCAD SHX Text 1-3A

AutoCAD SHX Text 1-2

AutoCAD SHX Text A

AutoCAD SHX Text N

AutoCAD SHX Text G

AutoCAD SHX Text

ROOF PERIMETER VENT

AutoCAD SHX Text L

AutoCAD SHX Text

(TYP)

AutoCAD SHX Text 1-1

AutoCAD SHX Text B

AutoCAD SHX Text

VAREC

AutoCAD SHX Text M

AutoCAD SHX Text

(TYP)

AutoCAD SHX Text H

AutoCAD SHX Text M

AutoCAD SHX Text E

AutoCAD SHX Text I

AutoCAD SHX Text L

AutoCAD SHX Text K

AutoCAD SHX Text J

AutoCAD SHX Text

(TYP)

AutoCAD SHX Text

(TYP)

AutoCAD SHX Text

(TYP)

AutoCAD SHX Text 1-3B

AutoCAD SHX Text D

AutoCAD SHX Text C

AutoCAD SHX Text F

TYN - 757R

TANK 757 ROOF LAYOUT

AutoCAD SHX Text

TYNDALL AIR FORCE BASE / USAF

AutoCAD SHX Text 2/21/20

AutoCAD SHX Text 19-091.03

AutoCAD SHX Text

DRAWING TITLE:

AutoCAD SHX Text

PROJECT:

AutoCAD SHX Text

OWNER/CLIENT:

AutoCAD SHX Text

DRAWN BY:

AutoCAD SHX Text

DATE:

AutoCAD SHX Text

JOB N0:

AutoCAD SHX Text

SKETCH NO:

AutoCAD SHX Text

JMD

AutoCAD SHX Text

TYN-757R

AutoCAD SHX Text

SPCC MANDATED SHOP-BUILT AST INSPECTIONS

AutoCAD SHX Text

SCALE:

AutoCAD SHX Text

NONE

AutoCAD SHX Text

26" CENTER ROOF VENT

AutoCAD SHX Text A

AutoCAD SHX Text

SCAFFOLD CABLE SUPPORT

AutoCAD SHX Text B

AutoCAD SHX Text 12"x25" ROOF HATCH

AutoCAD SHX Text C

AutoCAD SHX Text 10"x8" MANUAL GAUGE WELL

AutoCAD SHX Text D

AutoCAD SHX Text 10"x8" ATG WELL

AutoCAD SHX Text E

AutoCAD SHX Text 24"x78" PAN INSTALL HATCH

AutoCAD SHX Text F

AutoCAD SHX Text

10" BLIND

AutoCAD SHX Text G

AutoCAD SHX Text

AUTOGAUGE

AutoCAD SHX Text K

AutoCAD SHX Text

36" MANHOLE

AutoCAD SHX Text H

AutoCAD SHX Text 8"x6" WATER PROBE WELL

AutoCAD SHX Text I

AutoCAD SHX Text

ANTI-ROTATION CABLE

AutoCAD SHX Text J

AutoCAD SHX Text

2" NPT CAP

AutoCAD SHX Text L

AutoCAD SHX Text C

AutoCAD SHX Text C

AutoCAD SHX Text C

AutoCAD SHX Text H

AutoCAD SHX Text F

AutoCAD SHX Text C

AutoCAD SHX Text J

AutoCAD SHX Text D

AutoCAD SHX Text L

AutoCAD SHX Text A

AutoCAD SHX Text L

AutoCAD SHX Text B

AutoCAD SHX Text L

AutoCAD SHX Text I

AutoCAD SHX Text B

AutoCAD SHX Text L

AutoCAD SHX Text G

AutoCAD SHX Text E

AutoCAD SHX Text J

OSHA ACCESS STRUCTURE REPORT

OSHA Circumferential Stairway Data

OSHA Rq’d Actual

(in) min (in) max (in)

Handrail Height 32 OK 30 34 Step Width 28 OK 22 NA

Step Rise 9 OK NA NA Bottom Step Rise 9 OK 8 10

OSHA Approach Steps Data

OSHA Rq’d Actual

(in) min (in) max (in)

Handrail Height 32 OK 30 34 Step Width 43 OK 22 NA

Step Rise 10 1/2 OK 9 1/2 11/1/2 Bottom Step Rise 9 Not OK 9 1/2 11/1/2

BOTTOM STEP

RISE

APPENDIX ‘B’: API 653 CHECKLISTS FOR TANK INSPECTIONS

UL SWRI

API Other

Protected

9.800 BBL (to overflow)

Type: Type:

Size: Date Installed:

stainless steel End Conn: Size: 8" Material: stainless steel End Conn: Size: 12"

Issue To:

2017 (ATG, manual, and water probe wells, water draw-off system)

Release Prevention Barrier

Overfill Protection / Level Alarms:

LL,L,H, and HH and ATG Alarms Level alarms and 8" level control valve

Receipt Piping Configuration Issue Piping Configuration

Tank Piping

Secondary Containment

OOS: Oct 2006 and Feb 2015

Tank Specifications

Previous Tank Inspection Date:

Continuous Release Detection Monitoring

Type:

Date Installed:

Current Product:

43'-6" dia by 42'-3" tall

NA

Inspection Date:

Design Std

Tank Inspector Name:

Inspector Certification Number:

Overfill Protection:

Original

Monitoring well

Original

Useable Capacity:

Tank Construction and Configuration

Insulated

Coated

Plastic / Fiberglass

Other:

Jet-A

11,180 BBL (nameplate)

8,400 BBL (LLA to HLA)

Nominal Capacity:

welded south hydrant system

Liner (assumed)

API 653 EXTERNAL INSPECTION CHECKLIST

POL AreaProject Site:Project Name:

Project Location:

Brockenbrough Job No.:

SPCC AST Inspections

Dover AFB

General Inspection Information

19-091.03

Submitted to:

Contract No.:

USACE Omaha

W9128F-17-D-0017

Tank Facility No.:

Local Tank ID No.:

January 29, 2019

Tank Manufacturer:

Tank Construction Date:

Tank 757 Mike O'Connor

Vertical

Rectangular

Double Wall

Fire Resistant

Closed Top Dike

Change of Service:

Last Repair:

Tank Coatings:

Exterior Coating:

epoxy-polyurethane (assumed)

100% - epoxy (assumed)

Interior Coating:

Double Bottom

Matrix Services

Liner over concrete berms

65" by 134-6" by 134-6"

Level Alarms:

Material:

Tank Outside Dimensions:

Secondary Containment, Overfill, and CRDM welded

Horizontal Single Wall

Open Type Dike

Receipt From: Bulk

API 653 EXTERNAL INSPECTION CHECKLIST

POL AreaProject Site:Project Name: SPCC AST Inspections

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Piping on north and northeast. Dike drain on northeast approximately

40' from tank and 20' from piping. Dike drains toward tank on southwest and under piping on the north.

c)

TASK

Check for:

Tank Settlement

Review cathodic protection potential readings

Check for:

STATUS COMMENTS

Approximately 70' of vertical hairline cracking in ringwall. No expansion joints.

C.1.1.4 Rock

Measure foundation levelness and bottom elevations (See Annex B) a) b)

C.1.1.6 Housekeeping

Build-up of trash, vegetation, and other inflammables

ITEM

C.1.1 Foundation

C.1.1.2 Asphalt

e) Settlement around perimeter of tank

Check for:

d) a) b) a)

35V, 1A

C.1.1.1 Concrete Ring

Leaching of oil which has left rock filler exposed indicating hydrocarbon leakage

Tank settlement into asphalt base

C.1.1.7 Cathodic Protection

Site drainage away from the tank, associated piping, and manifolds

Check for:

Check for:

Presence of crushed rock under the steel bottom which usually results in severe underside corrosion.

Cavities under foundation;

vegetation against bottom of tank

Broken concrete, spalling, and cracks, especially under backup bars used in welding butt-welded annular rings under the shell

Indications of bottom leakage at drain openings in ring, back of water-draw basins, and top surface of ring

Run-off rainwater from shell draining away from the tank

Check for :C.1.1.3 Oiled Dirt or Sand b)

Settlements into the base

C.1.1.5 Site Drainage

Proper operation of dike drains

C.1.2.1 External Visual Inspection

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

C.1.2.3 Riveted Shell Inspection

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

C.1.2.4 Wind Girder (Floating

Roof Tanks) a)

Paint failures, pitting, and corrosion

Rivet and seam leaks on external surface

Check for:

Corrosion and thinning on plate and weld after cleaning the bottom angle area

Full fillet lap-welded vertical seams to increase joint efficiency b) c) c)

Broken welds and corrosion damage

(paint failure, pitting, corrosion, product build-up), especially where it occurs at tack-welded junction d)

ITEM TASK STATUS COMMENTS

Check for:

Grooving, corrosion, pitting, and coating failures b)

Corrosion loss and wear on the rivets

Reinforcing pads welded to shell at supports

Leaks and identify the location by sketch or photo

e) Drawings of riveted seams if available. Otherwise, dimension and sketch (or photograph) the rivet pattern: no. of rows, rivet size, pitch length, butt-riveted or lap-riveted joints a)

Check for:

Pitting on support welds to shell, especially on shell plates a) b)

c) Bottom-to-Foundation Seal

C.1.2. Shells

Check for:

C.1.2.2 Internal (Floating Roof

Tank)

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A Receipt TRV set at 50 psi.

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

ITEM TASK

a) Leaks at piping manifolds, flanges, and valves

C.1.3.3 Autogauge System Check for:

COMMENTS

Shell plate dimpling around nozzles, caused by excessive pipe deflection

Flange leaks and leaks around bolting c)

Check for:

b)

Cracks or signs of leakage on weld joint at nozzles, manholes, and reinforcing plates

Fire fighting system componentsb) c) d) e) f)

C.1.3.1 Manholes and Nozzles

C.1.3.2 Tank Piping Manifolds

C.1.3 Shell Appurtenances

Check for:

Damage on welds on shell-mounted davit clips above valves 6 inches and larger g)

Anchored piping which would be hazardous to the tank shell or bottom connections during earth movement

Adequate thermal pressure relief of piping to the tank

Proper operation of regulators for tanks with purge gas systems

Leaks at sample connections and proper valve operation

Damage and test the accuracy of temperature indicators h)

Sealing of insulation around manholes and nozzles

e) Adequate manholes flange and cover thickness on mixer manholes d) a)

STATUS

a) Leaks on autogauge tape guide and lower sheave housing (floating swings)

b) Damage on autogauge head

Pass Fail N/A

Pass Fail N/A Attached to pan.

Autogauge: 26'-8 3/16" ATG: 26'-8 3/16"

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

c) Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

h) Condition of board and legibility of board-type autogauges

Freedom of movement of marker and float

C.1.3.3 Autogauge System c) d)

C.1.3.4 Shell-mounted Sample

Station a) b)

Check for:

Function of valves and plugging in sample lines, including drain or return-to-tank line

Leaks in circulation pump and operating problems

Inspect condensate drain for presence of oil indicating leakage C.1.3.5 Heater (Shell Manhole

Mounted)

C.1.3.6 Mixer Check for:

c) Condition of power lines and connections to mixer

Bracing and supports for sample lines and equipment a) i) b)

Proper mounting flange and support

Leakage e) f) g)

Proper movement of tape by bumping the checker on autogauge head

Size and construction material of the autogauge tape guide and make note (floating roof tanks)

Proper movement of tape. Ask the operator if the tape tends to hang up during tank roof movement (floating roof tanks).

Actual product level compared to the reading on the autogauge. Make note. (max. variation is 2 in.)

No more than 2 feet of tape are exposed at the end of the tape guide when the roof is in lowest position

(floating roof tanks)

ITEM TASK STATUS COMMENTS

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

b) Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

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

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

ITEM TASK

Non-floating: Raise, then lower the swing line with the winch and check for cable lightness to confirm the swing line lowered properly

STATUS COMMENTS

C.1.3.7 Swing Lines: Winch a)

Operation

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 b) c)

C.1.3.8 Swing Lines: External

Guide System

Check for leaks at threaded and flanged joints

C.1.3.9 Swing Lines: Identify

Ballast Varying Need

Check for significant difference in stock specific gravity

Check for:C.1.3.10 Swing Lines: Cable

Material and Condition a) Corrosion over entire length, for non-stainless steel cable

Wear or fraying on all types of cable

C.1.3.11 Swing Lines: Product

Sample Comparison

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

C.1.3.12 Swing Lines: Target

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A Unable to open two of the perimeter vent inspection hatches.

Pass Fail N/A No detectable odor at 24 def F in high wind.

Bird droppings on roof and guardrails.

Small indications of standing water between rafters around perimeter.

Roof has only eight rafters.

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.)

ITEM TASK

C.1.4.2 Deck Plate External

Corrosion

STATUS

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

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.)

COMMENTS

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.

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

STATUS COMMENTS

C.1.4.6 Roof Insulation Check for:

a) b) c)

Crack and leaks in the insulation weather coat where runoff rain water could penetrate the insulation

C.1.4.7 Floating Roof Seal a)

Systems

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).

TASK

Wet insulation under the weather coat

Corrosion on the roof plate and holes near the edge of the insulated area by removing small test sections of insulation

ITEM

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.

1) ____________Opposite Pair 1; 2) ____________Opposite Pair 2 c) d) e) f) g)

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

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

Inspect visible metallic parts for corrosion and wear.

Inspect for openings in seals that would permit vapor emissions.

Inspect for protruding bolt or rivet heads against the shell.

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Check for:

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A

Pass Fail N/A Aluminum

ITEM TASK STATUS COMMENTS

C.1.4.7 Floating Roof Seal h)

Systems i) j)

Pull both primary and secondary seal systems back all around the shell to check…