Attachment J.2 Tank 3 (Fac 669) Ext '23.pdf

US Army Corps of Engineers Omaha District

API 653 In‐Service Inspection Report

Creech AFB, NV.

Tank‐3 (Facility 669)

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

(USACE POL‐MCX)

5/2/2023

Table of Contents

ACRONYMS AND ABBREVIATIONS

GENERAL SUMMARY

STATE REGULATIONS

PREVIOUS INSPECTION DATES

RECOMMENDED FUTURE INSPECTION DATES

A. GENERAL PROJECT INFORMATION

1. API 653 Inspection

2. Site Information

B. TANK INSPECTION COMMENTS

1. Tank Construction

2. Secondary Containment

3. Tank Foundation

4. Tank Bottom

5. Tank Shell

6. Tank Floating Roof

7. Tank Fixed Roof

8. Tank Appurtenances

9. Tank Piping System

10. Fire Protection System

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, or, Federal, State, and Local Codes

3. RECOMMENDED REPAIRS TO FULLY COMPLY WITH UFC 3‐460‐01, AW 78‐24‐27 Standards or as Part of Regular Maintenance

APPENDIX A: ENGINEERING CALCULATIONS…………………………………………………………………………………A‐1

APPENDIX B: EGINEEERING DATA………………………………………………………….........................................B‐1

APPENDIX C: ENGINEERING DRAWINGS……………………………………………………………………………………… C‐1

APPENDIX D: API 653 CHECKLIST FOR TANK INSPECTIONS ………………………………………………………. D‐1

APPENDIX E: PHOTOGRAPHS………………………………………………………………………………………………………. E‐1

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

Summary of Inspection

An API Standard 653 In‐Service inspection was conducted on Tank‐3 (Facility 669) at Creech AFB, NV.

The tank was originally constructed in 1979 and was reconstructed in 2014. The inspection was completed on May 2, 2023. The overall service life of the tank is estimated to be greater than 20 years.

Significant Findings (overview)

Mandatory None

Required Repairs

1. The secondary containment lacks an intermediate 18” tall berm wall between tanks.

Construction was underway on the secondary berm walls at the time of inspection. Weston Solutions was the prime contractor.

2. The fixed roof lacks installation of API scaffold supports.

3. The foundation‐to‐bottom projection (chime) interface is sealed. There are intermittent areas of failed sealant at the interface (approximately 6 LF = entire perimeter).

4. Shell nozzle I (24” Manway) has a reinforcement plate that was installed in two sections. The left half of the plate does not have a ¼” drilled and tapped tell‐tale hole installed.

Recommended Repairs

1. The roof mounted pan installation hatch does not have a reinforcement pad as required by AW

78‐24‐27 and UFC 3‐46‐01 Table 8‐1.

2. The tank is not equipped with a 4” low suction line in accordance with the standard design and

UFC 3‐460‐01.

3. The tank 6” issue line does not have a dedicated thermal relief system installed.

4. The tank is not equipped with an ENRAF ATG system in accordance with AW 78‐24‐27 Drawing

D.07 Detail 4 and the ATG policy per the letter issued by the Defense Logistics Agency. An 8‐inch aluminum slotted stilling well does exist to facilitate installation of the system.

5. The tank is not equipped with a water probe stilling well (VITO system) to meet the ATG policy per the letter issued by the Defense Logistics Agency.

6. The tank has a grounding cable located around the entire bottom circumference. The cable is exothermically welded at three locations on the shell and is not provided with shell mounted lugs with reinforcement pads per the standard design.

7. The tank fixed roof does not have a safety guardrail around its perimeter. The roof is a cone‐up design with a steep pitch. Roof access presents a safety hazard for routine inspection and maintenance.

8. There is an area of minor shell deflection under Nozzle J (6” Issue). This appears to be caused by no pipe support near the shell nozzle.

9. Minor coating failure and associated minor corrosion exist in the following areas: 4” Tank Receipt (F), 3” Water Draw (G), on the edge of the bottom extension.

Inspection Date: May 2, 2023

Inspection(s) Performed: API‐653 In‐Service (External)

Inspector(s): Richard M. Bailey

STATE REGULATIONS

API‐653 In‐Service Tank Inspections: NA

API‐653 Out‐of‐Service Tank Inspections: NA

NOTE: If there are no state regulations for tank inspections, 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: June 2014

API In‐Service (External) Inspection Date: June 2014

RECOMMENDED FUTURE INSPECTION DATES

API Out‐of‐Service (Internal) Inspection Date: June 2024

API In‐Service (External) Inspection Date: May 2028

Note: In accordance with UFC 3‐460‐03, the Out‐of‐Service inspection interval is every 10 years or as recommended by an appropriately certified tank inspector in the previous API 653 or STI SP001 inspection report.

Signature(s):

Richard M. Bailey, API‐653 # 30241 InterSpec, LLC.

GENERAL TANK INFORMATION

ITEM DESCRIPTION

Owner United States Air Force

Location Creech Air Force Base

Facility Number 669

Tank Number 3

State / Country Nevada, United States

City Indian Springs

Inspection Date May 02, 2023

Tank Manufacturer Brown And Steel

Design Standard API Standard 650 7th Edition

Date of Construction 1979 (Reconstructed in 2014)

Tank Contents Jet‐A (F‐24)

Tank Serial Number NA

Tank Diameter 18’

Shell Height 16’ 0”

Product Height 14’ 0”

Tank Capacity 26,000 Gallons

Foundation Concrete Pad

Construction

Bottom Lap‐Welded

Shell Butt‐Welded (Cylindrical)

Floating Roof Bolted and sealed

Fixed Roof Lap‐Welded

Material

Bottom Carbon Steel Unknown Grade

Shell Carbon Steel Unknown Grade

Floating Roof Aluminum Honey Comb

Fixed Roof Carbon Steel Unknown Grade

Cathodic Protection None

Interior Coating System Epoxy

Exterior Coating System Thin Film Urethane Covered Epoxy

Level Gauging VAREC MTG and Ronan ATG

Overfill Protection Hydraulically operated control valve

Piping

Receipt 4" Coated Carbon Steel

Issue 6" Coated Carbon Steel

Low Suction NA None

Water Draw‐Off 1” Stainless Steel

Level Alarms & Controls

Description RONAN ATG Independent

High‐High Level Alarm: 14’ 00‐00/16” 14’ 00‐00/16”

High‐Level Alarm: 12’ 10‐09/16” 12’ 10‐09/16”

Low‐Level Alarm: 2’ 04‐15/16” 2’ 04‐15/16”

Low‐Low Level Alarm: 1’ 09‐00/16” 1’ 09‐00/16”

High‐Level Control Shut‐off: 12’ 10”

Type of Internal Floating Roof

Aluminum Honeycomb Panel

A. GENERAL PROJECT INFORMATION

1. API 653 Inspection

This project will perform API 653 inspections of various tanks at facilities throughout the

United States. Additional consideration is given to federal, state, and local regulations, as well as applicable military criteria and general industry standards. An API Standard 653 In‐

Service inspection was performed for Tank 3 (Facility 669).

2. Site Information

On May 02, 2023, InterSpec, LLC performed an API 653 In‐Service visual inspection of Tank 3

(Facility 669), located at Creech AFB in Indian Springs NV.

B. TANK INSPECTION COMMENTS

1. Tank Construction

Tank 3 is a nominal 30,000 gallon (700 barrel), 18’ diameter by 16’ 0” tall, F‐24 Jet‐A, aboveground vertical storage tank. The tank was constructed in 1979 and reconstructed by

Weston Solutions in 2014. The tank was constructed to API‐650 7th Edition standards.

2. Secondary Containment

40 CFR 112.7(c) states that the entire secondary containment system, “including walls and floor, must be capable of containing oil and must be constructed so that any discharge from a primary containment system ... will not escape containment before cleanup occurs.” 40

CFR 112.8(c)(2) and 40 CFR 112.12(c)(2) state that diked areas must be “sufficiently impervious to contain oil.” The purpose of the secondary containment requirement is to prevent discharges, as described in 40 CFR 112.1(b); therefore, effective secondary containment methods must be able to contain oil until the oil is cleaned up. The secondary containment area consists of an earthen floor with earthen dike walls and is normally covered with a liner. At the time of inspection, construction was being done to the secondary containment. Tank 4” receipt piping was removed; the liner was removed and reshaping of the earthen berms was underway.

3. Tank Foundation

The tank does not have a cathodic protection system or means of bottom leak detection installed. The tank rests on a concrete pad. A visual evaluation of the concrete pad was conducted during the inspection for broken concrete, spalling, cracks, and vegetation against the bottom of the tank. The foundation has areas of hairline cracking. The tank bottom‐to‐ringwall sealant was evaluated and is deteriorated in many areas. This could allow for water intrusion underneath the bottom plates.

4. Tank Bottom

The bottom was not evaluated during this In‐Service Inspection.

5. Tank Shell

The shell is constructed of carbon steel of unknown material specification. The shell is a cylindrical design, butt‐welded together, consisting of two (2) courses. The shell exterior has a thin film urethane covered epoxy coating system. The coating was inspected for disbonding, adhesion, deterioration, and discoloration; it is in satisfactory condition. The tank appears to be stable and does not appear to be in danger of overturning or buckling due to high winds or seismic conditions. The shell was evaluated for remaining metal thickness utilizing ultrasonic technology. Thickness measurements are listed in the Engineering Data section in Appendix B. A service life evaluation performed shows the shell with > 30 years of remaining life under current conditions. The engineering calculations, as per API‐653, for the service life evaluation are shown in Appendix A under "Service Life Evaluation.” Based on data collected during this inspection, the tank shell is structurally sound.

6. Tank Floating Roof

The tank is equipped with an internal floating roof. The floating roof is an aluminum honeycomb panel type design. The double wiper perimeter roof seals and opening gaskets were not accessible for inspection.

7. Tank Fixed Roof

The fixed roof is a self‐supported cone‐up roof constructed of carbon steel material. The fixed roof is lap‐welded together consisting of 4 plates fillet‐welded to the shell. The fixed roof has a urethane epoxy exterior coating system. The coating was inspected for disbonding, adhesion, deterioration, and discoloration; it is in satisfactory condition.

Identified and evaluated the roof nozzles. Inspected the sample gauge hatch cover and latch and checked for proper seal integrity and cover operation. The fixed roof was evaluated for remaining metal thickness utilizing ultrasonic technology. Thickness measurements are listed in the Engineering Data section in Appendix B.

8. Tank Appurtenances

Note: The following table is an overview of the appurtenance status regarding UFC‐3‐460‐01 and AW 78‐24‐78 standards and does not reflect API standards, federal regulations, state regulations, and/or local regulations.

Overview of Appurtenance

Item Appurtenance

Installed Fully or partially

Meets Current Design

Standards

A. Manhole

1. 36‐inch manhole located above the IFR high leg position. ☐ ☐

2. At least two (2) fixed roof manholes. ☒ ☐

3. At least two (2) 36‐inch shell manholes. ☒ ☐

4. A bolted cover in the fixed roof for installation of IFR. ☒ ☒

B. Inspection Hatches

1. At least of four (4) 18x24‐inch inspection hatches on fixed roof with

IFR (min. spacing 32 feet).

C. Ladder/Stairs

1. Internal ladders with internal floating roofs. ☒ ☒

2. Access to high level shut‐off and alarms. ☒ ☒

D. Level Alarms An individual automatic level alarm system, independent of the gauging device or system. Include high, high‐high, low and low‐low level alarms. On aboveground tanks: provide a means to manually test each alarm sensor to ensure system operability without a full tank; locate level alarm equipment for ready access from ground level, stairway platforms, or roof access.

1. High‐High Level Alarm ☒ ☒

2. High Level Alarm ☒ ☒

3. Low Level Alarm ☒ ☒

4. Low‐Low Level Alarm ☒ ☒

E. Vents

1. Open atmospheric vents with weather hoods and bird screens. ☒ ☒

2. Emergency relief venting (a floating roof or frangible joint may be used to fulfill emergency relief requirements).

F. Gauge/Gauge Hatch/Stilling Wells

1. A mechanical liquid level gauge. ☒ ☒

2. Automatic Tank Gauging (ATG) (ENRAF fuel level & VITO water level systems).

3. One 10‐inch roof flanged nozzle with an 8‐inch aluminum, fully slotted, stilling well for ATG near the edge of the roof near the top of the stairway platform for fuel level ATG.

4. One 8‐inch roof flanged nozzle with a 6‐inch aluminum, fully slotted, stilling well for temperature and water bottom sensor, as close to or in the tank sump as possible for water level ATG.

5. One 10‐inch roof nozzle and an aluminum, slotted stilling well for gauging and sampling.

G. Piping Connection

1. Receipt Line ☒ ☒

Overview of Appurtenance

Item Appurtenance

Installed Fully or partially

Meets Current Design

Standards

2. Low Suction Line ☐ ☐

3. Issue Line. ☒ ☐

H. Overfill Protection

1. Overfill protection with a hydraulically operated diaphragm control valve.

I. Water Draw‐Off

1. Water draw‐off system. ☒ ☒

J. Ball Joints

1. Ball joints on pipes to relieve strain caused by tank settling or seismic activity or other means.

K. Cable Supports

1. On the fixed roof of all tanks, provide two scaffold cable supports ☐ ☐

a. Water Draw‐Off System

1) Water Draw‐Off Line: The water draw‐off piping consists of 1‐inch stainless steel issue and return piping. The line has two 2‐inch double‐block and bleed valves at the shell.

2) Product Saver Tank: The product saver tank (PST) is constructed of stainless steel.

b. Low Suction System

The tank is not equipped with a 4‐inch low suction nozzle and tie‐in to the 6” tank issue piping.

c. Issue Line

The 6‐inch issue line is constructed from coated carbon steel material. The line is not protected from over pressurization with a thermal relief system. The thermal relief system should consist of 1‐inch welded and flanged stainless steel pipe and fittings.

d. Receipt Line

The 4‐inch receipt line is constructed from coated carbon steel material. The line is protected from over pressurization with a thermal relief system. The thermal relief system consists of 1‐inch welded stainless steel and flanged pipe and fittings. The 4” piping was removed prior to the inspection in order to facilitate construction on the secondary containment.

e. Automatic Tank Gauging (Fuel Level)

The tank is equipped with a RONAN ATG system for electronic fuel level gauging. The system is installed in an 8‐inch slotted aluminum stilling well.

f. Automatic Tank Gauging (Water Level)

The tank fixed roof is not equipped with an ENRAF Vito water and temperature probe for electronic water level gauging located near the center of the tank.

g. Mechanical Tank Gauging

The tank is equipped with a Shand & Jurs mechanical tape level gauge for mechanical fuel level gauging.

h. Tank Sampling\Manual Gauging

The tank is equipped with an 8‐inch aluminum slotted stilling well for sampling and manual gauging.

i. Level Alarms\High Level Shut‐Off

The RONAN ATG system provides low, low‐low, high, and high‐high level alarms. The tank is equipped with independent low, low‐low, high, and high‐high level alarms mounted on the shell. The high level alarm assembly and high level shut‐off assembly are accessible from a shell mounted platform. The piping consists of 1‐inch welded/flanged stainless steel pipe and fittings.

j. Ladder and Platforms

The tank’s fixed roof is accessible by a fixed ladder mounted on the shell of the tank.

The ladder also accesses the platform located at the tank level alarms. The floating roof is accessible by an internal ladder located at the fixed roof access hatch.

k. Grounding

The tank has a grounding strap exothermically welded to four (4) equally spaced points around the circumference of the tank.

l. Anchoring

The tank is not anchored to the foundation. Tank anchoring is primarily determined by seismic conditions in the area. Although, some military facilities have experienced flooding in the containment that resulted in tanks being lifted off of their foundations.

9. Tank Piping System

Fuel is received and issued via trucks.

10. Fire Protection System

The fire department provides fire protection. The facility is equipped with two fire hydrants near the tank along the accessway.

C. FINDINGS AND RECOMMENDATIONS

The following information identifies the significant findings found during the tank inspection:

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.

None

2. REQUIRED REPAIRS to Fully Comply with API 653, or, Federal, State, and Local Codes

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. Secondary Berm Walls

OBSERVATION: The secondary containment lacks an intermediate 18” tall berm wall between tanks. Construction was underway on the secondary berm walls at the time of inspection. Weston Solutions was the prime contractor.

CODE REFERENCE: NFPA‐30 Section 22.11.2.6.

RECOMMENDATION: Design and install intermediate berm walls between tanks in order to satisfy the requirements of NFPA. (Quantity: 2 walls)

b. API Scaffold Supports

OBSERVATION: The fixed roof lacks installation of API scaffold supports.

CODE REFERENCE: UFC 3‐460‐01 Table 8‐1, item (jj) and API Standard 650, Section 5.8.8.

RECOMMENDATION: Install two (2) scaffold supports. Note: there are many appurtenances on the roof which might make this installation not practical. (Quantity: 2 supports)

c. Bottom to Foundation Seal

OBSERVATION: The foundation‐to‐bottom projection (chime) interface is sealed. There are intermittent areas of failed sealant at the interface (approximately 6 LF = entire perimeter).

CODE REFERENCE: Seal should be maintained in good working order to prevent corrosion of the underside of the tank bottom (UFC 3‐460‐03 Section 8‐4.1 B) and API Standard 653

Paragraph C.1.2.1 (c).

RECOMMENDATION: Do not caulk the end (side) of the chime. See AW 78‐24‐27 Drawing D.04 Detail 3. Repair the coating on the chime area. (Quantity: 60 LF)

d. Two Section Reinforcement Plate

OBSERVATION: Shell nozzle I (24” Manway) has a reinforcement plate that was installed in two sections. The left half of the plate does not have a ¼” drilled and tapped tell‐tale hole installed.

CODE REFERENCE: API Standard 653 Section 9.7.2.

RECOMMENDATION: Drill and tap a tell‐tale hole in accordance with API 650 Section 5.7.5.1, API 653Para. 9.7.2 and perform pneumatic pressure test on hole by applying 15 PSI in accordance with API 650 Section 7.3.4. (Quantity: 1)

3. RECOMMENDED REPAIRS TO FULLY COMPLY WITH UFC 3‐460‐01, AW 78‐24‐27 Standards or 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.

a. No Reinforcement Pad for the Roof Mounted Pan Installation Hatch

OBSERVATION: The roof mounted pan installation hatch does not have a reinforcement pad as required by AW 78‐24‐27 and UFC 3‐46‐01 Table 8‐1.

CODE REFERENCE: AW 78‐24‐27 Drawing 5.02 Note R and UFC 3‐460‐01 Table 8‐1 Item (g).

RECOMMENDATION: Provide the existing pan installation hatch with a reinforcement pad in accordance with AW 78‐24‐27 and UFC 3 460‐01 requirements. (Quantity: One Pad)

b. Four‐Inch Low Suction Line

OBSERVATION: The tank is not equipped with a 4” low suction line in accordance with the standard design and UFC 3‐460‐01.

CODE REFERENCE: UFC 3‐460‐01 Table 8‐1 item (z) and AW 78‐24‐27 G.05 and Drawing

D.07, Detail 5.

RECOMMENDATION: Install a 4” low suction to meet the requirements of UFC 3‐460‐01 and AW 78‐24‐27 standard design. The system should be installed as close to the 6” issue nozzle as possible. (Quantity: One System)

c. Issue Line Thermal Relief System

OBSERVATION: The tank 6” issue line does not have a dedicated thermal relief system installed.

CODE REFERENCE: UFC 3‐460‐01, Section 9‐2.1 (e) and AW 78‐24‐27 Drawing D.10 Detail 04.

RECOMMENDATION: Provide a thermal relief system on the 6” issue line. (Quantity: 1)

d. ENRAF ATG System

OBSERVATION: The tank is not equipped with an ENRAF ATG system in accordance with AW

78‐24‐27 Drawing D.07 Detail 4 and the ATG policy per the letter issued by the Defense

Logistics Agency. An 8‐inch aluminum slotted stilling well does exist to facilitate installation of the system.

CODE REFERENCE: AW 78‐24‐27 Drawing D.07 Detail 4 and UFC 3‐460‐01 Table 8‐1 item (s).

RECOMMENDATION: Install an automatic tank gauge ENRAF system to meet the ATG policy per the letter issued by the defense Logistics Agency. (Quantity: 1 system)

e. VITO Water and Temperature probe

OBSERVATION: The tank is not equipped with a water probe stilling well (VITO system) to meet the ATG policy per the letter issued by the Defense Logistics Agency.

CODE REFERENCE: AW 78‐24‐27 Drawing D.07 Detail 3 and UFC 3‐460‐01 Table 8‐1 item (s).

RECOMMENDATION: Install an automatic tank gauge water probe (VITO system) to meet the ATG policy per the letter issued by the defense Logistics Agency. (Quantity: 1 system)

f. Tank Grounding

OBSERVATION: The tank has a grounding cable located around the entire bottom circumference. The cable is exothermically welded at three locations on the shell and is not provided with shell mounted lugs with reinforcement pads per the standard design.

CODE REFERENCE: AW 78‐24‐27 Drawing ED.02 Details 1 and 2.

RECOMMENDATION: Reconfigure the tank grounding system to provide lugs for exothermic welded attachments. (Quantity: 1 system)

g. Roof Perimeter Safety Handrail

OBSERVATION: The tank fixed roof does not have a safety guardrail around its perimeter.

The roof is a cone‐up design with a steep pitch. Roof access presents a safety hazard for routine inspection and maintenance.

CODE REFERENCE: AW 78‐24‐27 Drawing D.11 Detail 5.

RECOMMENDATION: Install a safety guardrail around the roof perimeter. (Quantity: 1)

h. Shell Deflection Under Nozzle

OBSERVATION: There is an area of minor shell deflection under Nozzle J (6” Issue). This appears to be caused by no pipe support near the shell nozzle.

CODE REFERENCE: API 653 C.1.3.1 (b).

RECOMMENDATION: Consider adding another pipe support near the 6” nozzle or at a minimum, continue to monitor the area during subsequent inspections. (Quantity: 1)

i. Areas of Minor Coating Failure

OBSERVATION: Minor coating failure and associated minor corrosion exist in the following areas: 4” Tank Receipt (F), 3” Water Draw (G), on the edge of the bottom extension.

CODE REFERENCE: UFGS 09 97.13.27 (Exterior Coating of Steel Structures).

RECOMMENDATION: Perform maintenance touch up coating to affected areas. (Quantity: 25

SF)

Appendix A

Engineering Calculations

1. Shell Service Life Evaluation

2. Shell Settlement Evaluation

Shell Service Life Evaluation

Where:

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

t nom = nominal shell thickness, in inches.

t act = current measured shell thickness, excluding pits and corrosion, in inches.

t prev = previous measured shell thickness, excluding pits and corrosion or t nom , in inches.

D = nominal diameter of the tank, in feet.

H = height from the bottom of the shell course under considerations to the established maximum liquid level, in feet.

H c = calculated safe fill height, in feet, for the current product.

G = specific gravity of the contents.

Y = specified minimum yield strength of the plate; use 30,000 pounds per square inch if not known

(N/A for riveted tanks).

T = smaller of the specified minimum tensile strength of the plate or 80,000 pounds per square inch;

use 55,000 psi if not known (N/A for riveted tanks).

S = The maximum allowable stress, in pounds per square inch. For welded tanks, use the smaller of 0.80Y or 0.429T for the bottom and the second course or the smaller of 0.88Y or 0.472T for all other courses. For riveted tanks, use S =21,000 psi. For elevated temperatures above 200OF, the maximum allowable stress shall be the smaller of 2/3 the minimum yield strength multiplied by the M-factor (M) of API Standard 650 Appendix M or the product design stress value listed in Table M-1a or M-1b of API Standard 650.

E = original joint efficiency for the tank. Use Table 4-2 from API Standard 653 if original E is unknown; E =1.0 when evaluating the retirement thickness in a corroded plate, when away from welds or joints by at least the greater of one inch or twice the plate thickness. For riveted tanks, use E =1.0 for shell plates when greater than 6 inches from rivets; use the value of E from API Standard 653 Table 4-3 when within 6 inches of rivets.

L r = remaining life of the shell, in years.

C r = shell corrosion rate, in inches per year.

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

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

Y = years between the previous measured shell thickness (t prev ) and the current measured shell thickness (t act ), in years.

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

tmin =

2.6(H−1)DG

SE

Lr = tact − tmin

Cr Cr = tprev − tact Y Iut = tact − tmin 2Cr

Iv = tact − tmin

4Cr

1) Minimum Required Thickness

D = 18 feet

G = 0.84

Y = 44 years

Course No.

Plate Specification

Course Height (feet)

Product Height (feet) (H )

Maximum Allowable

Stress (psi) (S )

Joint Efficiency

(E )

Minimum Acceptable Thickness (inches) (t min )

Previous Measured Thickness (inches) (t prev )*

Current Measured Thickness (inches)

(t act )

1 Unknown 8.00 14.00 23,600 1.00 0.100 0.188 0.182 2 Unknown 8.00 6.00 23,600 1.00 0.100 0.188 0.184

*The t prev values were based on t nom .

0.000

0.050

0.100

0.150

0.200

1 2

In ch es

Course

Thickness Graph tprev tact tmin

2) Corrosion Rate, Remaining Life and Inspection Intervals

Course No.

Corrosion Rate

(in./yr) (C r )

Remaining Life

(years) (L r )

Next Visual

Inspection (years)

(I v )

Next Ultrasonic Thickness Inspection

(years) (I ut )

1 0.00013 655 5 15 2 0.00008 1056 5 15

* Let C r =0.0002 inches per year for calculation purposes.

Note: The engineering data used to calculate in-service period of operation (Remaining Life) assumes the tank remains in the same service and all corrosion rates remain constant. The maximum safe fill height for the tank is not limited other than by the established maximum operating liquid level and any other appurtenance such as overflow, vents, or firefighting system.

0.00000

0.00002

0.00004

0.00006

0.00008

0.00010

0.00012

0.00014

1 2

In ch es P er Y ea r

Course

Course Corrosion Rate Graph

Corrosion Rate

3) Projected Thickness Chart and Graph

Course #1:

Year Thickness tmin

2023 0.182 0.1 2028 0.181 0.1 2033 0.181 0.1 2043 0.180 0.1 2053 0.178 0.1

*based on same service and corrosion rates.

Course #2:

Year Thickness tmin

2023 0.184 0.1 2028 0.184 0.1 2033 0.183 0.1 2043 0.182 0.1 2053 0.182 0.1

*based on same service and corrosion rates.

Anticipated Thickness (5 yrs)* Anticipated Thickness (10 yrs)* Anticipated Thickness (20 yrs)* Anticipated Thickness (30 yrs)*

Current Thickness:

Current Thickness:

Anticipated Thickness (5 yrs)* Anticipated Thickness (10 yrs)* Anticipated Thickness (20 yrs)* Anticipated Thickness (30 yrs)*

0.000

0.050

0.100

0.150

0.200

2023 2025 2027 2029 2031 2033 2035 2037 2039 2041 2043 2045 2047 2049 2051 2053

In ch es

Year

Course #1 Projected Thickness Graph

Thickness tmin

0.000

0.050

0.100

0.150

0.200

2023 2025 2027 2029 2031 2033 2035 2037 2039 2041 2043 2045 2047 2049 2051 2053

In ch es

Year

Course #2 Projected Thickness Graph

Thickness tmin

Shell Settlement Evaluation

S max = maximum permissible out-of-plane deflection, in feet.

L = ΠD /N = arc length between measurement points, in feet.

D = tank diameter, in feet N = number of survey points.

Y = yield strength, in pounds per square inch (psi).

E = young's modulus, in pounds per square inch (psi) H = tank height, in feet

D = 18 feet N = 8 L = 3.14(18)/8 = 7.0686 feet Y = 30,000 psi E = 29,000,000 psi H = 60.05 feet

L 2 = 49.9649 square feet

11(49.9649)(30,000) 2(29,000,000)(60.05)

1) Maximum Permissible Out-of-Plane Deflection Calculation

S max = = 0.0047 feet

𝑆𝑚𝑎𝑥 11𝐿 𝑌

2𝐸𝐻

|S i | = U i - (1/2U i-1 + 1/2U i+1 ) Where:

|S i | = magnitude of the calculated out-of-plane deflection, in feet.

U i = Out-of-Plane settlement of point "i ", in feet

(+) when above cosine curve (-) when below cosine curve

Point Actual Curve

Fit U i U i+1 U i-1 S i |S i |

1 0.17708 0.00000 0.17708 0.20450 0.12116 0.12116 0.01425

2 0.15625 0.03509 0.12116 0.17708 -0.09896 -0.09896 0.08210

3 0.02083 0.11979 -0.09896 0.12116 -0.19061 -0.19061 0.06424

4 0.01389 0.20450 -0.19061 -0.09896 -0.23958 -0.23958 0.02134

5 0.00000 0.23958 -0.23958 -0.19061 -0.16804 -0.16804 0.06026

6 0.03646 0.20450 -0.16804 -0.23958 0.06771 0.06771 0.08210

7 0.18750 0.11979 0.06771 -0.16804 0.20450 0.20450 0.04948

8 0.23958 0.03509 0.20450 0.06771 0.17708 0.17708 0.08210

R 2 = 0.87 Note: Settlement evaluation must be done using the arc length method.

1) Out-of-Plane Deflection Calculation

Shell Settlement Graph

0.005 0.01

0.015 0.02

0.025 0.03

0.035 0.04

0.045 0.05

0.055 0.06

0.065 0.07

0.075 0.08

0.085 0.09

0.095 0.1

0.105 0.11

0.115 0.12

0.125 0.13

0.135 0.14

0.145 0.15

0.155 0.16

0.165 0.17

0.175 0.18

0.185 0.19

0.195 0.2

0.205 0.21

0.215 0.22

0.225 0.23

0.235 0.24

0.245 0.25

0.255

4 5 6 7 8 1 2 3 4

E le va ti on s

(f ee t)

Data PointsShell Settlement

Optimum Cosine Curve

Min. Settlement at (Pt 1)

Max. Settlement at (Pt 4)

S arc = settlement arc length between start and end point, in feet.

S i = maximum out-of-plane settlement within the settlement arc length, in inches.

K = factor based on tank roof type (per B.3.2.2).

Roof TypeFixed Roof K = 10.5

Sarc # Start Pt End Pt End Pt Sarc (ft) Si (in) Smax (in)

1 8 8 8 56.5487 0.0000 0.1841 Pass

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

API 653 B.2.2.5 Evaluation by Settlement Arc Length Method (For R 2 less than 0.9)

Si < Smax →

Arc Length Evaluation

𝑆 𝑚𝑖𝑛 𝑘 𝑆 𝐷 𝐻

𝑌 𝐸

, 4.0

3 4

0.25

0.5

0.75

1.25

1.5

1.75

2.25

2.5

2.75

3.25

8 1 2 3 4 5 6 7 8

E le va ti on s

(i nc he s)

Data Points

Appendix B

Engineering Drawings

1. Shell Layout

2. Fixed Roof Layout

3. Containment Layout

Remarks/Legend:

Owner/Operator:

Inspection Firm:

Date: Revision Number: Revision Date:

Drawing Title: Tank Description: Drawing Number:

Creech AFB - Indian Springs, NV

InterSpec, LLC.

05/02/2023 N/A N/A

Tank #3 (Facility 669) S-1Shell Layout [1 of 2]

Tank diameter is 18', and tank height is 16' - 1/2".

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

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

A - 36" Manhole B - 1" High Level Control Assemblies C - 1" High Level Control Assemblies D - 1" Low Level Control Assemblies E - 1" Low Level Control Assemblies F - 4" Receipt Line G - 3" Water Draw-Off H - 2" Water Draw-Off

A

ATG

D

E

C

B

F G H

2-22-1

1-1 1-2

8'-0"

8'-0"

Inspection Firm:

Date: Revision Number: Revision Date:

Drawing Title: Tank Description: Drawing Number:

Creech AFB - Indian Springs, NV

InterSpec, LLC.

05/02/2023 N/A N/A

Tank #3 (Facility 669) S-1Shell Layout [2 of 2]

Tank diameter is 18', and tank height is 16' - 1/2".

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

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

I - 24" Manhole J - 6" Issue Line

I

J

Overflow Vent

1-3

2-32-2

Inspection Firm:

Date: Revision Number: Revision Date:

Drawing Title: Tank Description: Drawing Number:

Creech AFB - Indian Springs, NV

InterSpec, LLC.

05/02/2023 N/A N/A

Tank #3 (Facility 669) R-1Fixed Roof Layout [1 of 1]

Tank diameter is 18', and tank height is 16' - 1/2".

A - 8" Vent B - 8' Blank C - 6" J-Vent D - Roof Circulation Vent/Inspection Hatch

E - 3" ARD

F - 4" Blank G - 10" Electronic Level Indicator H - 10" Sample Gauge I - 24" Manhole J - 6" P/V Vent K - Hatch

A

B

K

E

C

C

E

FD

D

J

H

G I

MTG

Vertical Ladder J

Inspection Firm:

Date: Revision Number: Revision Date:

Drawing Title: Tank Description: Drawing Number:

Creech AFB - Indian Springs, NV

InterSpec, LLC.

05/02/2023 N/A N/A

Tank #3 (Facility 669) C-1Containment Layout [1 of 1]

PRT

Tank #1 (Facility 667)

Tank #3 (Facility 669)

Tank #4 (Facility 663)

4" Receipt Line

6" Issue Line

6" Issue Line

4" Receipt Line

PST

- 6" Issue Line

- 4" Receipt Line

- 4" Receipt Line

Appendix C

Engineering Data

1. Shell Settlement Measurements

2. Tank 360° Thickness Measurements

3. Shell 9’s Thickness Measurements

4. Tank Shell Drop

5. Tank Nozzle and Reinforcement Pad Measurements

6. Tank Fixed Roof Thickness Measurements

7. Tank Accessway Measurements

1 49 3/8 2 51 1/3 3 52 1/4 4 52 1/3 5 52 1/2 6 52 1/16 7 50 1/4 8 49 5/8

NOTE: The Rod Heights are based on the actual height of the transit at the time of the data collection. This data should only be used for this report. Point #1 is located at Vertical Shell Seam #1.

Shell Settlement Measurements

Point No. Rod Height (inches)

Location # 1 is with 2" of Plate 1 - 1

1 0.189 51 0.187 2 0.191 52 0.185 3 0.19 53 0.186 4 0.187 54 0.188 5 0.188 55 0.189 6 0.192 56 0.189 7 0.191 57 0.189 8 0.191 58 0.193 9 0.191 59 0.191

10 0.187 60 0.188 11 0.188 12 0.191 13 0.188 14 0.184 15 0.187 16 0.185 17 0.189 18 0.19 19 0.193 20 0.194 21 0.186 22 0.188 23 0.188 24 0.189 25 0.188 26 0.185 27 0.182 28 0.19 29 0.189 30 0.187 31 0.185 32 0.184 33 0.188 34 0.186 35 0.192 36 0.188 37 0.19 38 0.183 39 0.188 40 0.19 41 0.193 42 0.187 43 0.195 44 0.189 45 0.184 46 0.187 47 0.186 48 0.187 49 0.189 50 0.186

Tank Shell 360 degree Measurement every 1 foot (within 12 inches of chime)

Location # Thickness in inches Location # Thickness in inches

1 2 3 4 5 6 7 8 9

0.19 0.186 0.187 0.189 0.193 0.188 0.192 0.19 0.194

0.187 0.191 0.186 0.188 0.19 0.191 0.191 0.19 0.187

0.187 0.183 0.191 0.185 0.188 0.186 0.192 0.191 0.194

1 - 2

Thickness Measurements (inches) Point Numbers

Shell Plate Thickness Measurements

Plate # 1 - 1

1 - 3

1 4 7

25 5 8

3 6 9

Point No.

Course #1

Course #2

1 0.194 0.191 2 0.189 0.188 3 0.191 0.189 4 0.191 0.185 5 0.193 0.187 6 0.187 0.193 7 0.183 0.195 8 0.189 0.184 9 0.193 0.185

10 0.195 0.193

0.245 measurements are evenly spaced down each course along the path of each drop. The thickness in inches. The lowest UT measurements are in RED, and the highest UT measurements are in shell course.

Shell Drop Thickness Measurements

Nom. 0o 90o 180o 270o

A 36" Manway 0.500 0.507 0.513 0.501 0.503 B 1" High Level Control Assembly NA NA NA NA NA C 1" High Level Control Assembly NA NA NA NA NA D 1" Low Level Control Assembly NA NA NA NA NA E 1" Low Level Control Assembly NA NA NA NA NA F 4" Tank Receipt 0.337 0.338 0.329 0.331 0.327 G 3" Water Draw Off 0.300 0.292 0.284 0.301 0.294 H 2" Return Nozzle 0.154 0.161 0.154 0.148 0.152 I 24" Manway 0.375 0.377 0.374 0.371 0.368 J 6" Tank Issue 0.432 0.431 0.428 0.421 0.440

Nom. 0o 90o 180o 270o

A Circular Pad 0.188 0.184 0.180 0.183 0.187 B Rectangular Insert 0.375 0.377 0.377 0.375 0.374 C Circular Pad 0.188 0.185 0.188 0.190 0.193 D Circular Pad 0.375 0.374 0.375 0.375 0.371 L Circular Pad 0.188 0.187 0.187 0.188 0.189

NOTE: The Sheet Number corresponds to the shell plate in the first shell course. The X-Axis is measured from the Seam #1 in the first shell course to the center of the nozzle. Seam #1 is the first seam left of the first manway left of the stairway in the first shell course viewing from the outside. The Y-Axis is measured from the tank bottom to the center of the nozzle.

Nozzle Reinforcement Measurements

Nozzle Measurements

Shell Nozzle and Nozzle Reinforcement Measurements

Noz Desig. Reinforcement Description

Thickness Measurements (inches)

Thickness Measurements (inches)Noz Desig. Nozzle Description

Fixed Roof Plate Thickness Measurements

1 2 3 4 5 1 0.187 0.191 0.19 0.184 0.181 E 2 0.183 0.188 0.185 0.18 0.179 E 3 0.184 0.191 0.189 0.19 0.188 E 4 0.187 0.185 0.186 0.187 0.189 E

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

Plate

Number Point No. Plate

Type

C-7

Appendix D

API Standard 653 Checklist for Tank Inspections

1. Tank In‐Service Inspection Checklist

Tank In-Service Inspection Checklist

API 653

Reference Item

Completed (X)

C.1.1 FOUNDATION

a) Measure foundation levelness and bottom elevations. ☒

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.

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

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

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

e) Check for settlement around perimeter of tank. ☒

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.

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

C.1.1.3 OILED DIRT OR SAND

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

C.1.1.4 ROCK

a) 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.

C.1.1.5 SITE DRAINAGE

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

b) Check operating condition of the dike drains. ☒

C.1.1.6 HOUSEKEEPING

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

C.1.1.7 CATHODIC PROTECTION

a) Review cathodic protection potential readings. ☐

C.1.2 SHELLS

C.1.2.1 EXTERNAL VISUAL INSPECTION

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

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

c) Inspect the bottom-to-foundation seal, if any. Visually inspect for grooving, corrosion, pitting, and coating failures.

C.1.2.2 INTERNAL (FLOATING ROOF TANK)

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

C.1.2.3 RIVETED SHELL INSPECTION

a) Inspect external surface for rivet and seam leaks. ☐

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

c) Inspect rivets for corrosion loss and wear. ☐

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

Reference Item

Completed (X)

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.

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.

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

c) Note whether supports have reinforcing pads welded to shell. ☐

C.1.3 SHELL APPURTENANCES

C.1.3.1 MANWAYS AND NOZZLES

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

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

c) Inspect for flange leaks and leaks around bolting. ☒

d) Inspect sealing of insulation around manways and nozzles. ☐

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

C.1.3.2 TANK PIPING MANIFOLDS

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

b) Inspect fire-fighting system components. ☒

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

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

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

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

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

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

C.1.3.3 AUTOGAUGE SYSTEM

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

b) Inspect autogauge head for damage. ☒

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

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

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

f) Compare actual product level to the reading on the autogauge (maximum variation is 2 in.).

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

h) Inspect condition of board and legibility of board-type autogauges. ☐

i) Test freedom of movement of marker and float. ☒

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.

b) Check circulation pump for leaks and operating problems. ☐

c) Test bracing and supports for sample lines and equipment. ☐

C.1.3.5 HEATER SHELL MANWAY MOUNTED

a) Inspect condensate drain for presence of oil indicating leakage. ☐

Reference Item

Completed (X)

C.1.3.6 MIXER

a) Inspect for proper mounting flange and support. ☐

b) Inspect for leakage. ☐

c) Inspect condition of power lines and connections to mixer. ☐

C.1.3.7 SWING LINES: WINCH OPERATION

a) Non-floating. Raise, then lower the swing line with the winch, and check for cable tightness to confirm that swing line lowered properly.

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.

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.

C.1.3.8 SWING LINES: EXTERNAL GAUGE SYSTEM

a) Check for leaks at threaded and flanged joints. ☐

C.1.3.9 SWING LINES: IDENTIFY BALLAST VARYING NEED

a) Check for significant difference in stock specific gravity. ☐

C.1.3.10 SWING LINES: CABLE MATERIAL AND CONDITION

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

b) All cable: check for wear or fraying. ☐

C.1.3.11 SWING LINES: PRODUCT SAMPLE COMPARISON

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

C.1.3.12 SWING LINES: TARGET

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.

C.1.4 ROOFS

C.1.4.1 DECK PLATE INTERNAL CORROSION

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

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

C.1.4.2 DECK PLATE EXTERNAL CORROSION

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

C.1.4.3 ROOF DECK DRAINAGES

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

C.1.4.4 LEVEL OF FLOATING ROOFS

a) 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

a) 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.

Reference Item

Completed (X)

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.

b) Inspect for wet insulation under the weather coat. ☐

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

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.

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

d) Inspect fabric for deterioration, holes, tears, and cracks. ☐

e) Inspect visible metallic parts for corrosion and wear. ☐

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

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

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

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. ☐

C.1.5 ROOF APPURTENANCES

C.1.5.1 SAMPLE HATCH

a) Inspect condition and functioning of sample hatch cover. ☒

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

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

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

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

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

g) Test operation of system. ☒

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).

C.1.5.2 GAUGE WELL

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

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

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

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

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

Reference Item

Completed (X)

C.1.5.3 FIXED ROOF SCAFFOLD SUPPORT

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

C.1.5.4 AUTOGAUGE: INSPECT HATCH AND GUIDES

a) Check the hatch for corrosion and missing bolts. ☐

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

C.1.5.5 AUTOGAUGE: FLOAT WELL COVER

a) Inspect for corrosion. ☐

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

C.1.5.6 SAMPLE HATCH (INTERNAL FLOATING ROOF)

a) Check overall conditions. ☒

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

c) When equipped with a recoil reel opening device, check for proper operations. ☐

C.1.5.7 ROOF MOUNTED VENTS INTERNAL FLOATING ROOF

a) Check condition of screens, locking and pivot pins. ☐

C.1.5.8 GAUGING PLAT FORM DRIP RING

a) 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

a) 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.

C.1.5.10 REMOVABLE ROOF LEG RACKS

a) Check for leg racks on roof. ☐

C.1.5.11 VACUUM BREAKERS

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

C.1.5.12 RIM VENTS

a) Check condition of the screen on the rim vent cover. ☐

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

C.1.5.13 PONTOON INSPECTION HATCHES

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

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

c) If pontoon…