Attachment K.5 FAC 50302 Inspection Report 2017.pdf
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US Army Corps of Engineers Omaha District
API 653 In-Service Final Inspection Report
Fort Rucker, Alabama Facility 50302
Tank 1
US Army Corps of Engineers Center of Expertise for Petroleum, Oils and Lubricants
USACE POL-TCX
05 September 2017
API 653 In-Service Inspection Report Fort Rucker, Alabama
TABLE OF CONTENTS
ACRONYMS AND ABBREVIATIONS
GENERAL SUMMARY
THIS INSPECTION
PREVIOUS INSPECTION DATES
RECOMMENDED FUTURE INSPECTION DATES
GENERAL TANK INFORMATION
A. GENERAL PROJECT INFORMATION
1. API 653 Inspection
2. Site Information
B. TANK INSPECTION COMMENTS
1. Tank Construction
2. Tank Foundation
3. Tank Shell
4. Tank Appurtenances
5. Tank Coating
6. Tank Piping System
7. Fire Protection System
8. Secondary Containment
C. FINDINGS AND RECOMMENDATIONS
1. Mandatory Repairs per API 653, UFC 3-460-01, or AW 78-24-27 Standards
2. Significant Findings per API 653, UFC 3-460-01, or AW 78-24-27 Standards
3. Repairs to Fully Comply with API 653, UFC 3-460-01, or AW 78-24-27 Standards
4. Recommended Repairs as Part of Regular Maintenance
APPENDIX A: ENGINEERING CALCULATIONS AND DRAWINGS
SHELL SETTLEMENT SURVEY
SHELL THICKNESS CALCULATIONS
SHELL/ROOF ULTRASONIC THICKNESS MEASUREMENTS
TANK DRAWINGS
OSHA ACCESS STRUCTURE REPORT
APPENDIX B: API 653 CHECKLISTS FOR TANK INSPECTIONS
APPENDIX C: PHOTOGRAPHS
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
FAC Facility
HLA High Level Alarm
HLCV High Level Control Valve
HHLA High-High Level Alarm
LLA Low Level Alarm
LLLA Low-Low Level Alarm
MFL Magnetic Flux Leakage
MFE Magnetic Flux Exclusion
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
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
UT Ultrasonic Testing
VT Visual Testing
GENERAL SUMMARY
Austin Brockenbrough & Associates, LLP (Brockenbrough) was retained by Omaha District USACE under Contract No. W9128F-12-D-0006 Delivery Order No. 0023 to perform API Standard 653 In-Service Inspections. As required by this task, Brockenbrough executed a tank inspection site visit to Fort Rucker, Hanchey Army Heliport, located in Dale County, Alabama. An API 653 In-Service (visual external) Inspection was conducted for Tank Facility No.
50302 (Tank 1) on June 20, 2017. This inspection was performed in accordance with API Standard 653, “Tank Inspection, Repair, Alteration, and Reconstruction,” and the referenced contract. The confined space between the internal floating roof and the fixed roof was not entered during the inspection. All observations made during this in-service (visual external) inspection were made from the exterior of the tank.
Tank Facility 50302 is a 21’-3” diameter by 17’-6” tall, single wall, vertical, field erected tank with a nominal storage capacity of 1,000 barrels of jet fuel (F-24). Based on the nameplate data the tank was fabricated by Chicago Bridge & Iron Company in 1967. Secondary containment is provided by a concrete containment area with vertical concrete dike walls shared by adjacent Tank Facility 50305 (Tank 2), 50304 (Tank 3), and 50303 (Tank 4). The tank is built on a concrete slab on grade. Since there are no as-built drawings of the tank available at this time, the presence of a release prevention barrier could not be confirmed. The tank appears to be equipped with a sacrificial anode cathodic protection system. Details of the tank construction and appurtenances are included in Section ‘B’.
There are no mandatory repairs noted that need immediate attention. 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’.
There is a current work order to provide new coatings on the tank and associated piping.
The next API Standard 653 In-Service (visual external) Inspection should be performed by an API 653 Inspector by June 2022. The last out-of-service inspection was performed in 2011. The inspection schedule indicated herein is based on the 2011 report. The next ultrasonic thickness inspection of the shell should be performed by February 2026. While the current version of UFC 3-460-03 requires the next out-of-service inspection occur after 10 years, an upcoming revision allows the frequency to be extended as determined by a certified API 653 tank inspector. As the tank was inspected in 2011, and there are some concerns with foundation settlement, we recommend the next API Standard 653 Out-Of-Service (internal and external) Inspection should be performed by 2026. This inspection should include an external and internal inspection and include an examination of the tank bottom by magnetic flux leakage (MFL or MFE) technology and an ultrasonic thickness inspection of the tank shell. This inspection should include a thorough code compliance evaluation as well.
GENERAL TANK INFORMATION
ITEM DESCRIPTION
Owner U.S. Army
Location Fort Rucker
Facility Number Facility 50302
Tank Number Tank 1
State / Country Alabama / U.S.A.
City Daleville
Inspection Date June 20, 2017
Tank Manufacturer Chicago Bridge and Iron Company
Design Standard API Std 650
Date of Construction 1967
Tank Contents Jet Fuel (F-24)
Tank Serial Number Unknown
Tank Diameter 21’-3”
Shell Height 17’-6”
Product Height 12’ – 1 10/16” (ATG Reading at the Time of Inspection)
Tank Capacity 1,000 barrels (Nominal Capacity)
Foundation Concrete Slab (per previous tank inspection report)
Construction
Bottom Lap-welded cone down bottom (Per previous tank inspection report)
Shell (2) butt-welded shell courses
Floating Roof Lap welded steel pan (Per previous tank inspection report)
Fixed Roof Self-supported, lap-welded, domed
Material
Bottom Carbon steel (Per previous tank inspection report)
Shell Carbon steel (Per previous tank inspection report)
Floating Roof Carbon steel (Per previous tank inspection report)
Fixed Roof Carbon steel (Per previous tank inspection report)
Cathodic Protection Sacrificial Anode Cathodic Protection System
Interior Coating System
Epoxy-Epoxy-Epoxy (assumed)
Exterior Coating System
Epoxy-Epoxy-Polyurethane (assumed)
Level Gauging Varec Tape Level Gauge; Enraf Automatic Tank Gauge (ATG)
Overfill Protection High Level Control Valve; Independent shell mounted High-high, High, and Low Level Alarms; a roof mounted High Level Alarm
Piping Receipt 6” nozzle (4” pipe) Stainless Steel
Issue 6” nozzle (4” pipe) Stainless Steel
Low Suction 3” Stainless Steel
Water Draw-Off 1” Stainless Steel
Level Alarms Independent shell mounted High-high, High, and Low Level Alarms; Roof mounted High Level Alarm
Type of Internal Floating Roof
Lap welded steel pan (Per previous tank inspection report)
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.
For Facility 50302, an API Standard 653 In‐service (visual external) Inspection was performed. This inspection also included a foundation settlement survey.
2. Site Information
On June 20, 2017 Brockenbrough performed an API 653 In‐Service (visual external) Inspection of Tank
Facility 50302 (Tank 1) located at Fort Rucker. Fort Rucker is a located in Dale County, Alabama, and is surrounded by the neighboring cities of Daleville, Ozark and Enterprise. Fort Rucker is a primary flight training base for Army Aviation and is home to the United States Army Aviation Center of Excellence
(USAACE) and the United States Army Aviation Museum.
B. TANK INSPECTION COMMENTS
1. Tank Construction
Tank Facility 50302 is a nominal 1,000-barrel, 21’-3” diameter by 17’-6” tall, F-24, aboveground vertical storage tank. Per the previous tank inspection report, the tank was constructed by Chicago
Bridge & Iron Company to API 650 design standard in 1967. Base personnel have strapping tables for determining tank volume.
2. Tank Foundation
The tank rests on a 6-inch high concrete slab. Since there were no as-built drawings of the tank available at the time of this inspection, the presence of a release prevention barrier could not be determined. The foundation was visually evaluated during the inspection for broken concrete, spalling, cracks, and vegetation against the bottom of the tank. The concrete slab was found to be in good condition with only a few minor hairline cracks. The bottom-to-foundation seal appears to have failed in several areas around the circumference of the tank bottom. A shell settlement survey was performed during the inspection in accordance with Appendix B of API Standard 653 and the tank was found to exceed the allowable limits. Settlement results are listed in Appendix A.
3. Tank Shell
The vertical and cylindrical shell consists of two butt‐welded courses. The exterior of the shell was visually inspected and evaluated for plumbness, roundness, peaking and banding. The coating was also evaluated for deterioration.
4. Tank Appurtenances
a. Tank Roof
The tank is constructed with a self-supported lap-welded domed roof. Isolated areas of coating failure and corrosion were observed on the roof, center vent, flanges, manholes, nozzles and nozzle reinforcing pads, nuts, and bolts. There was excessive mold and algae growth on the tank roof and roof appurtenances.
https://en.wikipedia.org/wiki/United_States_Army_Aviation_Branch https://en.wikipedia.org/wiki/United_States_Army_Aviation_Center_of_Excellence https://en.wikipedia.org/wiki/United_States_Army_Aviation_Museum
b. Venting
This tank features a roof center vent and five shell mounted perimeter circulation vent/overflows.
These vents provide adequate venting capacity based on the size of the tank.
c. Gauging
The tank’s Enraf ATG is installed through an 8-inch roof nozzle. The tank also has a Varec tape level gauge whose reading does not align with the Enraf ATG reading. There is a dedicated 8-inch sample gauging hatch with plug and reel mounted on the roof.
d. Level Alarms
The low and high level alarm chambers are mounted on the exterior of the tank shell, and there is an additional roof mounted high level alarm. The tank is equipped with low, high and high-high level alarms independent of the tank gauging system. An independent low-low level alarm is not present as is required by military criteria.
e. Stairs and Platforms
The tank’s steel roof is accessible by a circumferential stairway mounted on the shell of the tank.
The circumferential stairway is directly welded to the shell. The width and rise of the stairway steps and the height of the handrails appear to be in general compliance with OSHA criteria.
However, the bottom circumferential step is approximately 16 inches above the dike basin, and all the other step risers are approximately 9 inches. OSHA requires that the step risers be consistent.
f. Grounding and Bonding
There are two grounding cables connected to ground lugs welded to the tank shell.
5. Tank Coating
The interior coating system of the tank is assumed to be epoxy-epoxy-epoxy. The external coating system appeared to be a standard military coating system (epoxy-epoxy-polyurethane). Coating failure and corrosion were observed in multiple locations on the tank shell, tank bottom extension, tank roof, shell manhole covers, and bolts. There was extensive mold and algae growth observed on the tank roof, handrails, and the shell. As the tank is used to store oil and the interior is coated with epoxy, deterioration of the interior of the shell since the previous inspection was performed is extremely unlikely.
6. Tank Piping System
Fuel is received through a 6-inch nozzle and 4‐inch stainless steel piping from an adjacent Truck Off-load Station and is issued through a 6-inch nozzle and 4-inch stainless steel piping to the adjacent
Truck Fillstands.
7. Fire Protection System
There are several fire hydrants noted within 300 feet of this tank.
8. Secondary Containment
Secondary containment is provided by a concrete containment area with concrete curbs between 6 and
12 inches tall shared by adjacent Tank Facility 50305 (Tank 2), 50304 (Tank 3), and 50303 (Tank 4).
There are no intermediate dike walls present between the tank containment areas. The secondary containment was visually evaluated during the inspection. The containment is of sufficient size to contain a total tank loss plus one foot of freeboard.
C. FINDINGS AND RECOMMENDATIONS
Tank Facility 50302 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 several items observed that are not in full compliance with federal, state, and local codes or military criteria.
1. MANDATORY REPAIRS per API 653, UFC 3-460-01, or AW 78-24-27 Standards
Mandatory repairs represent items that require immediate attention, in order to prevent imminent risk to system operators, equipment integrity, or the adjacent environment. The tank should remain out of service until these repairs are completed. No mandatory repairs are required to be performed.
2. SIGNIFICANT FINDINGS per API 653, UFC 3-460-01, or AW 78-24-27 Standards
The following information identifies the significant findings found during the tank inspection.
a. Repair Coating System on Tank and Tank Appurtenances
OBSERVATION: Extensive coating failure and minor corrosion were observed at multiple locations on the tank shell, tank roof, roof appurtenances, roof guardrail (at the base), deck platform and grating, circumferential stairway, tank bottom extension, and manhole covers and bolts.
CODE REFERENCE: UFC 3-460-01, Section 8-3.10, requires the exterior of fuel storage tanks and appurtenances to be coated.
RECOMMENDATION: Perform already scheduled repairs to repaint all tanks and piping under Work
Order RCK-H51-362.
b. Repair the Tank Bottom Extension and Bottom-to-Foundation Seal
OBSERVATION: The tank bottom-to-foundation seal has deteriorated and systematically failed.
Evidence of minor corrosion and coating failure at the tank bottom extension was observed. Some vegetation and organic growth was also observed at the sealant.
CODE REFERENCE: UFC 3-460-03, Section 8-4.10 B, requires the seal to be maintained in good working order to prevent corrosion of the underside of the tank bottom.
RECOMMENDATION: Remove the bottom-to-foundation seal. Prep and coat the tank bottom extension per AST standards and replace the tank bottom-to-foundation seal.
c. Repair Weep Holes on Shell Reinforcement Pads
OBSERVATION: The tell-tale holes on the shell reinforcement pads around the tank nozzles are plugged with a grease plug.
CODE REFERENCE: API 650, sections 5.7.5.1 and 5.7.6.1 require tell-tales on all shell reinforcement pads for leak detection around the nozzles to be open to the atmosphere.
RECOMMENDATION: Remove the grease plugs from the tell-tale holes in the reinforcement pads.
Install elbowed drain plug for leak detection.
d. Replace Tape Level Gauge System
OBSERVATION: The tape level gauge read 39 feet and 1 inches, while the ATG read 12 feet and 1
10/16 inches. The tape level gauge was inoperable.
CODE REFERENCE: API 653 External Inspection Checklist Item C.1.3.3.f) requires a maximum of
2 inches of variation between the actual product level compared to the reading on the autogauge.
RECOMMENDATION: Replace the tape level gauge system. Ensure new tape is attached to a weight resting on top of the floating pan and not directly attached to the pan or as recommended by the manufacturer.
e. Replace Level Control Valve
OBSERVATION: The 4-inch level control valve is constructed out of aluminum.
CODE REFERENCE: NFPA 30 paragraph 27.4.3 does not allow valves made of low melting point materials to be used within secondary containment areas. UFC 3-460-01 paragraph 3-6.7 prohibits use of aluminum valves in DoD Fuel Systems.
RECOMMENDATION: Replace the 4-inch aluminum control valve with a steel or ductile iron level control valve.
f. Provide Hold-Off Distance Marker at Sampling/Gauging Hatch
OBSERVATION: There are no hold-off distances painted or stenciled on or adjacent to the sampling/gauging hatches.
CODE REFERENCE: API 653 In-Service Checklist, C1.5.2b.
RECOMMENDATION: Provide a stencil indicating the hold-off distance and marking adjacent to or directly on the sample/gauging hatches.
g. Modify Bottom Stairway Steps
OBSERVATION: The circumferential stairway step rise is generally 9 inches. However, the bottom circumferential stairway step is approximately 16 inches above the dike basin.
CODE REFERENCE: OSHA 29 CFR 1910.24 (f) requires the rise of stairway steps to be uniform throughout its entire length, including at its foundation.
RECOMMENDATION: Provide a dike basin mounted step with a landing 9 inches below the bottom shell mounted stairway step.
3. REPAIRS to Fully Comply with API 653, UFC 3-460-01, or AW 78-24-27 Standards
These items represent repairs and/or upgrades that could be performed to bring the tank into full compliance with current standards, but that do not represent potential risks to system operators, equipment integrity, or the adjacent environment. Our recommendations to perform or not to perform these repairs and/or upgrades take into consideration the cost of the repair, the operational benefit of the repairs, the age of the tank/system, operator safety, environmental risks, and equipment integrity.
a. Shell Settlement
OBSERVATION: Per API 653 Appendix B calculations for shell settlement, the tank exceeds the allowable limits. See Appendix A of this report for the calculations.
CODE REFERENCE: API 653 Appendix B.
RECOMMENDATION: Current data and calculations show that the tank settlement exceeds the applicable limits described in API 653. Generally, the tank settlement differential is a good indicator of settlement related to foundation problems. Since this tank is built on a concrete slab and due to the small diameter of the tank, the allowable construction tolerances, and no signs of damage due to settlement, we do not recommend any modifications at this time. However, Brockenbrough recommends that the shell settlement be monitored at all subsequent inspections to detect any future changes.
b. Upgrade Thermal Relief System
OBSERVATION: The existing thermal relief valve piping on the tank receipt and issue piping have sight flow indicators and there are no testing tees present.
CODE REFERENCE: UFC 3-460-01, Section 9-3.5.1 does not allow sight flow indicators in thermal relief piping.
RECOMMENDATION: Modify and upgrade thermal relief piping to remove sight flow indicators and provide testing tees.
c. Provide Scaffold Supports
OBSERVATION: There are no scaffold cable supports present on the tank roof.
CODE REFERENCE: UFC 3-460-01, Table 8-1, Item ff requires two scaffold cable supports on the fixed roof in accordance with API 650.
RECOMMENDATION: Provide two scaffold cable supports in accordance with API 650.
d. Provide Low-low Level Alarm
OBSERVATION: The tank has low, high, and high-high levels switches, but does not have a low-low level switch.
CODE REFERENCE: UFC 3-460-01, Table 8-1, Item l requires independent high-high, high, low, and low-low level alarms.
RECOMMENDATION: Modify low level alarm shell mounted chamber and provide low-low level alarm.
e. Provide Intermediate Containment Between Tanks
OBSERVATION: There is no intermediate containment between the four tanks – Facilities 50303, 50304, 50305 and 50302. The existing dike wall heights are between 6” and 12” high.
CODE REFERENCE: NFPA 30 Section 22.11.2.6 requires that each diked area containing two or more tanks shall be subdivided, preferably by drainage channels or at least by intermediate dikes, in order to prevent minor spills from a tank from endangering adjacent tanks within the diked area.
Intermediate dike walls are required to be a minimum of 18” high.
RECOMMENDATION: An 18” intermediate dike wall is not feasible due to the short height of the existing dike walls. Provide an intermediate drainage channel separating Tanks 3 and 4 from Tanks
1 and 2. An intermediate dike wall
f. Provide Circumferential Stair Landing
OBSERVATION: There is no circumferential stairway landing for maintaining the high-level alarm chamber.
CODE REFERENCE: DoD Standard Design AW 78-24-27 requires new storage tank designs to include a circumferential stairway landing for maintaining shell-mounted level alarms.
RECOMMENDATION: Provide a circumferential stairway landing for maintaining the shell-mounted level alarms.
g. Upgrade Low Suction Piping
OBSERVATION: The low suction piping has a ball valve at the tank skin and is not hard piped to the main suction.
CODE REFERENCE: UFC 3-460-01, Paragraph 4-6.8.4 requires double block and bleed type valves on all tank shell connections. DOD Standard Design AW 78-24-27 requires the low suction line to be connected to the issue line for complete draining of the tank contents via the same pumps used to issue product.
RECOMMENDATION: Provide a double block and bleed isolation valve at the skin of the tank per DOD
Standard Design AW 78-24-27. However, due to the location of the low suction nozzle relative to the main suction and the proper functionality of the tank operations, we do not recommend any piping modifications at this time.
h. Upgrade Water Draw-off Piping
OBSERVATION: The water draw-off nozzle is one inch and has a ball valve at the tank skin.
CODE REFERENCE: UFC 3-460-01, Paragraph 4-6.8.4 requires double block and bleed type valves on all tank shell connections. DOD Standard Design AW 78-24-27 requires the water draw-off nozzle to be two inches in diameter so that a double block and bleed valve can be installed.
RECOMMENDATION: Replace the one inch diameter Water Draw-off nozzle with a two inch nozzle and provide a two inch double block and bleed at the tank skin per DOD Standard Design AW 78-
24-27.
4. RECOMMENDED REPAIRS as Part of Regular Maintenance
Recommended repairs represent items that should be addressed in a timely manner in order to prevent future potential risks to system operators, equipment integrity, or the adjacent environment.
a. Remove Mold and Algae
OBSERVATION: There is mold and algae growing on the tank roof, shell, and appurtenances. The mold and algae growth may cause and/or accelerate degradation of the exterior coating system.
CODE REFERENCE: UFC 3-460-01 paragraph 8-3.10 requires the exterior of the tank to be coated.
RECOMMENDATION: Power wash the exterior of the tank and apply an algae and mold inhibitor on a regular basis.
b. Provide NFPA Hazard Label
OBSERVATION: The tank is not labeled with a NFPA hazard warning label.
CODE REFERENCE: NFPA 30, paragraph 21.7.2.1 requires ASTs to be labeled in accordance with
NFPA 704.
RECOMMENDATION: Provide a new NFPA hazard warning label in accordance with NFPA 704.
c. Remove Debris within the Dike Area
OBSERVATION: There is buildup of organic debris in the containment dike area which may lead to deterioration of the containment area and coating system over time.
CODE REFERENCE: API 653 In-Service Inspection Checklist, C.1.1.6 requires all containment areas to be free of trash, vegetation, and inflammables.
RECOMMENDATION: Remove debris and perform regular maintenance to prevent deterioration of the containment slab.
APPENDIX A: ENGINEERING CALCULATIONS AND DRAWINGS
SHELL SETTLEMENT SURVEY
Austin Brockenbrough & Associates, L.L.P.
Job No. 16-088.01 Location: Fort Rucker
Date: 07/11/2017 Subject: Tank 50302 Shell Settlement Evaluation By: Jed Caldwell
API 653 Appendix B Optimum cosine curve, B 2.2.4.e)
Z = a + b x cos(theta + c)
Diameter (D) = 21.25 (ft)
Number of equally spaced data points (ft)= 8 L = Arc length between measurement points (ft) = 8.34 Tank Height (H) = 17.50 (ft)
Height of
Weld * Z U S
0 -47.125 0.00 0.13 0.13 0.15
1 -46.875 0.25 0.23 -0.02 -0.01
2 -46.500 0.63 0.47 -0.16 -0.13
3 -46.375 0.75 0.70 -0.05 -0.12
4 -46.625 0.50 0.80 0.30 0.35
5 -46.375 0.75 0.70 -0.05 -0.06
6 -46.375 0.75 0.47 -0.28 -0.25
7 -46.875 0.25 0.23 -0.02 0.06
8 -47.125 0.00 0.13 0.13 0.13
Maximum out-of-plane deflection = 0.35
* = measured elevation *HI (Height of Instrument) Z = calculated rigid body tilt (in)
U = out-of-plane settlement = S = out-of-plane deflection = z-y
Y = yield strength of shell material (PSI) = 30,000 E = Youngs modulus of elasticity (lbf/in2) = 2.90E+07 S allowable (in) (API 653 B.3.2.1) = (L^2*Y*11)/(2EH)*12 = 0.27 in
R^2 =(Syy - SSE)/Syy = 0.70 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. 16-088.01 Location: Fort Rucker
Date: 07/11/2017 Subject: Tank 50302 Shell Settlement Evaluation By: Jed Caldwell
API 653 B.2.2.5.1 Evaluation by Settlement Arc Length Method
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 (in) Smax
0 41.7 0.750 0.55 Si < Smax → NOT OKAY
4 16.7 0.250 0.22 Si < Smax → NOT OKAY
Evaluation of the settlement by the arc length method indicates the settlement exceeds the applicable limits described in API 653 B.3.2.2.
0.00
0.20
0.40
0.60
0.80
1.00
0 2 4 6 8 10
Measured Elevation (in)
Si7 Si3
SHELL THICKNESS CALCULATIONS
The following shell thickness analysis is taken from a previous API 653 Internal Inspection Report prepared by
HMT Inspection in February of 2006. The analysis is included as a reference and should be used for informational purposes only.
SHELL THICKNESS EVALUATION
Shell Plate Thickness and Safe Fill Height Calculations The following calculations determine the minimum acceptable shell plate thickness (tmin) and safe fill heights (product and water) for tanks equal to or less than 200 feet in diameter in accordance with Section 4 of API 653.
Minimum Acceptable Shell Plate Thickness (tmin) tmin = 2.6 D (H - 1) G Where:
S E tmin = Minimum acceptable shell plate thickness (in.)
D = Tank Diameter (ft.)
H = Height from bottom of the shell course under consideration to the maximum liquid level (ft.)
G = Specific Gravity of product S = Allowable stress from API 653 (lbf/in2) E = Joint Efficiency CA = Corrosion Allowance (in.)
Variables
Tank Height (ft): 17.25
D (ft): 21.25
G (Water): 1.00
G (Product): 0.82
Course
Height (ft) H (ft) Allowable Stress
S (Psi) Joint Efficiency
E CA (in) Shell
Height (ft)
1 9.00 17.25 23,600 0.85 0.010 9.00
2 8.25 8.25 23,600 0.85 0.010 17.25
The following table shows the checks required for tmin:
Check No.
Measured Thickness* Check Calculated Thickness Limit
1 tave > = t(LV) = t(min) + CA
2 t1 > = t(LV) = t(min) + CA
3 t2 > = t(LV) = 0.6 x t(min) + CA
4 tp > = t(LV) = 0.5 x t(min) tave = average UT readings in uncorroded areas t1 = lowest average thickness in “pitted area” t2 = minimum thickness in “pitted area” tp = remaining shell thickness at an isolated pit
* All tanks will have a tave for each course, but many tanks will have no other measurements for t1, t2, or tp if no corrosion or pitting exists in that course.
Using above formula/variables, the following table shows the checks required for tmin:
Check #1 Check #2 Check #3 Check #4 t(ave) t(LV)* ** t1 t(LV)* ** t2 t(LV)* ** tp t(LV)* **
Course (in) (in) P/F (in) (in) P/F (in) (in) P/F (in) (in) P/F
1 0.183 0.110 P N/A N/A -- N/A N/A -- N/A N/A --
2 0.187 0.110 P N/A N/A -- N/A N/A -- N/A N/A --tave = average UT readings on shell of tank. Use smallest average on a shell course or vertical drop less the average coating thickness.
t(LV) = calculated limited thickness value P/F indicates shell course passes or fails calculation/checks.
Checks 2, 3, and 4 are not applicable because there were no areas of corrosion or pitting on the shell courses.
Safe Fill Height
Controlling Safe Fill Height
Fluid Height (ft)
Water No Restriction
Product No Restriction
Shell Service Life Evaluation and Corrosion Rates
Shell
Nominal Thickness
(in.)
Current Thickness
(in.)
Years since Construction
N Min
Thickness (in.)
RCA
Next
External (years)
Next
UTM
(years)
1 0.250 0.183 44 0.0015 0.110 48 5 15
2 0.250 0.187 44 0.0014 0.110 54 5 15
N = Corrosion rate, if N is 0 then use the N of the next lower shell course
RCA = Remaining Corrosion Allowance
Interval to next formal external inspection = RCA/4 or 5 years maximum
Interval to next Ultrasonic Thickness Measurements = RCA/2 or 15 years maximum
SHELL/ROOF ULTRASONIC THICKNESS MEASUREMENTS
The following shell and roof thickness analysis is taken from a previous API 653 Internal Inspection Report prepared by HMT Inspection in February of 2006. The analysis is included as a reference and should be used for informational purposes only.
Table B-3 Shell Plate Ultrasonic Thickness Readings Roof
SHELL
COURSE
PLATE 2-1 PLATE 2-2 PLATE 2-3
.178 .189 .188
.182 .194 .191
.190 .189 .184
AVG. .187
Circumferential weld C2
SHELL
COURSE
PLATE 1-1 PLATE 1-2 PLATE 1-3 PLATE 1-4
.197 .199 .196 .199 .202 .200 .190 .185 .187 .190 .194 .188
.203 .206 .205 .201 .202 .204 .191 .189 .192 .193 .198 .188
.190 .199 .196 .191 .197 .189 .186 .181 .186 .188 .184 .219
AVG. .199 .198 .187 .194
Circumferential weld C1
Thicknesses represented in inches.
Refer to Drawing A-2 in Appendix A for plate numbers.
Table B-4 Fixed Roof Plate Ultrasonic Thickness Readings
PLATE 1 PLATE 2 PLATE 3
.188 .188 .180 .181
.186 .188 .186
.185 .187 .182 .183 .185 .184
AVG. .187 .185 .183
PLATE 4 PLATE 5 PLATE 6
.178 .179 .182 .182 .183 .183
.180 .189 .186
.177 .181 .186 .188
AVG. .179 .185 .185
Average Thickness = 0.184”
Refer to Drawing A-3 in Appendix A for plate numbers.
Table B-5 Floating Roof (Lower Deck) Plate Ultrasonic Thickness Readings
PLATE 1 PLATE 2 PLATE 3 PLATE 4
.187 .187 .188
AVG. .187 .187 .188
PLATE 5 PLATE 6 PLATE 7 PLATE 8
.183 .182
.187 .197
.195
AVG. .189 .187 .197 .182
Average Thickness = 0.188”
Refer to Drawing A-3 in Appendix A for plate numbers.
TANK DRAWINGS
The following tank drawings are taken from a previous API 653 Internal Inspection Report prepared by HMT
Inspection in February of 2006. Drawings are included as a reference and should be used for informational purposes only. Locations of appurtenances, shell and roof plates, etc. are approximate.
Drawing A-2 Shell Plate Layout
N2 N1
N8
N7
N11 N9
N12
N6N4 N5
N3
N10
GROUND
(TYP)
LOWER
PLATFORM
UPPER
PLATFORM
TAPE LEVEL
GAUGE
W/O
1-1 1-2 1-3 1-4 1-1
2-1 2-2 2-3
9'-0"
8'-3"
MWA
SHELL VENT W/
BIRD SCREEN (X6)
= ULTRASONIC THICKNESS MEASUREMENT LOCATION. SEE DATA PAGE FOR RECORDED THICKNESS.
Refer to Table B-3, “Shell Plate Ultrasonic Thickness Readings” and Appendix F for tank shell thickness measurements.
Drawing A-3 Roof Layout
N14
8" ENRAF ATG
N15
N13
HATCH 1
REPAD
H.R.
VERTICAL H.R.
POST W/ REPAD
ELEVATED LANDING
PLATFORM
H.R. = GUARDRAIL
6'-0"
STAIR DOWN
= ULTRASONIC THICKNESS MEASUREMENT LOCATION. SEE DATA
PAGE FOR RECORDED THICKNESS.
Table B-6 Nozzles and Appurtenance Table
NOZZLE
NOZZLE SIZE
(Diameter or
Width/Height)
REPAD
SHAPE
REPAD
SIZE
(W X H)
REPAD
THICKNESS
NOZZLE
THICKNESS
H1 H2
NOZZLE
LOCATION
(Measured circumferentially from Manway A)
NOTES
MWA 24" A 5'-6"x4'-6" .387 .339 2’-6” 3” 0'-0" Manway
W/O 16"x8" D 3'-10"x1'-2" .240 .294 - - 38'-0" Flush Wash-out
N1 1 1/2" - - - - 61/2” - 19'-0" Water Draw-off
N2 1 1/2" - - - - 1’-4” - 18'-6" LLA
N3 1 1/2" - - - - 3’-8” - 18'-6" LLA
N4 4" C 1'-3"x10" .267 .445 71/2” 21/2” 20'-6" Low Suction
N5 6" C 1'-6"x1'-3" .309 .507 1’-6” 10” 26-0" Receipt
N6 6" C 1'-6"x1'-3" .243 .417 1’-6” 10” 60'-0" Main Suction (Issue)
N7 1 1/2" - - - - 14’-1” - 18'-0" HLA/HLCV
N8 1 1/2" - - - - 16’-3” - 18'-0" HLA
N9 1 1/2" - - - - 16’-0” - 20-0" HLCV
N10 4" est. - - - - - - - Shell Overflow Pipe (previously nozzles)
N11 4" est. - - - - - - - Shell Overflow Pipe (previously nozzles)
N12 4" est. - - - - - - - Shell Overflow Pipe (previously nozzles)
N13 1 3/4" - - - - Roof Mechanical Tape Level Gauge
N14 24" - - - .240 Roof Center Vent
N15 8" - - - .242 Roof SOR HHLA
Hatch 1 24" B 3'-8" .243 .250 Roof Hatch w/ ENRAF ATG
Thickness measurements are in inches. Refer to Drawings A-2 and A-3 in Appendix A for nozzle numbers and locations.
H1 = C/L of pipe to edge of roof or chime.
H2 = Edge of tank or chime to nearest weld toe.
REPAD SHAPES:
OSHA ACCESS STRUCTURE REPORT
OSHA Stairway Data
Handrail Actual
(in)
OSHA Rq’d min (in) max (in)
Handrail Height 31 30 34 Step Width 30 22 NA Step Rise 9 NA NA
Bottom Step Rise 16 8 8
APPENDIX B: API 653 CHECKLISTS FOR TANK INSPECTIONS
UL SWRI
API Other
Protected
Type: Type:
Size: Date Installed:
SS End Conn: Size: 4" Material: SS End Conn: Size: 4"
Issue To:
Nominal Capacity:
Welded
Truck fillstandsReceipt From: Tank truck off-load
Jeff King
Vertical
Rectangular
Double Wall
Fire Resistant
Closed Top Dike
Change of Service:
Last Repair:
Tank Coatings:
Exterior Coating:
3-part epoxy (assumed)
Unknown
Tank Facility No.:
Local Tank ID No.:
6/20/2017
50302
Tank Manufacturer:
Tank Construction Date:
Tank 1
API 653 EXTERNAL INSPECTION CHECKLIST
Fort RuckerProject Site:Project Name:
Project Location:
Brockenbrough Job No.:
SPCC Mandated AST Inspections - Group 11 Hanchey Airfield, Ft. Rucker, Alabama
General Inspection Information
16-088.01 Submitted to:
Contract No.:
USACE POL - TCX
W9128F-12-D-0006
2012Previous Tank Inspection Date:
Interior Coating:
54102
Horizontal
Inspection Date:
Design Std
Tank Specifications
Tank Inspector Name:
Inspector Certification Number:
Insulated
Coated
Plastic / Fiberglass
Other:Double Bottom
Tank Construction and Configuration
Single Wall
Open Type Dike
Concrete dike
Level Alarms:
Material: Welded
Unknown
Overfill Protection:
Tank Outside Dimensions:
Continuous Release Detection Monitoring
Type:
Secondary Containment, Overfill, and CRDM
Overfill Protection / Level Alarms:
Low, high, & high-high independent level alarms High level control valve on receipt piping
Receipt Piping Configuration
Useable Capacity: 1,106 BBL
Release Prevention BarrierSecondary Containment
Current Product:
21'-3"ø x 17'-6" tall
N/AHorton Tank Chicago Bridge & Iron
F-24 jet fuel
1,000 BBL
Issue Piping Configuration
Tank Piping
Unknown
Date Installed:
API 653 EXTERNAL INSPECTION CHECKLIST
Fort RuckerProject Site:Project Name: SPCC Mandated AST Inspections - Group 11
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 Review cathodic protection potential readings
Check for:
b)
C.1.1.4 Rock Check for:
b) a) a)
Measure foundation levelness and bottom elevations (See Annex B) See level survey results c)
Check for:
ITEM
C.1.1 Foundation
C.1.1.1 Concrete Ring
STATUS COMMENTSTASK
Tank Settlement b)
Run-off rainwater from shell draining away from the tank
Check for :C.1.1.3 Oiled Dirt or Sand e)
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 a)
Settlements into the base
Check for:
C.1.1.7 Cathodic Protection
Site drainage away from the tank, associated piping, and manifolds
C.1.1.5 Site Drainage
Check for:
Proper operation of dike drains C.1.1.6 Housekeeping
Buildup of trash, vegetation, and other inflammables
Tank settlement into asphalt base C.1.1.2 Asphalt
Leaching of oil which has left rock filler exposed indicating hydrocarbon leakage d)
Presence of crushed rock under the steel bottom which usually results in severe underside corrosion.
Sacrificial anodes
Settlement around perimeter of tank
C.1.2.1 External Visual Inspection
Pass Fail N/A
Pass Fail N/A
Pass Fail N/A
Pass Fail N/A No access
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
COMMENTS
Rivet and seam leaks on external surface
Check for:
c) Bottom-to-Foundation Seal
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)
Full fillet lap-welded vertical seams to increase joint efficiency b)
a) b)
C.1.2.4 Wind Girder (Floating Roof Tanks) a)
Dry rotted and starting to fail
Leaks and identify the location by sketch or photo c)
Corrosion and thinning on plate and weld after cleaning the bottom angle area
C.1.2. Shells
ITEM TASK
Reinforcing pads welded to shell at supports
Broken welds and corrosion damage (paint failure, pitting, corrosion, product buildup), especially where it occurs at tack-welded junction d)
Check for:
Check for:
Exterior coating system is failing. Peeling with minor corrosion on roof and tank shells
Minor corrosion on and around chime. Mold and algae on tank
STATUS
b)
Grooving, corrosion, pitting, and coating failures
C.1.2.2 Internal (Floating Roof Tank) c)
Check for:
Corrosion loss and wear on the rivets
Pitting on support welds to shell, especially on shell plates
Paint failures, pitting, and corrosion
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
Pass Fail N/A
TRVs - SFIs are installed in TRV assemblies
Mechanical tape gauge is inoperable
C.1.3.3 Autogauge System
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
Leaks at sample connections and proper valve operation Damage and test the accuracy of temperature indicators
a) Leaks on autogauge tape guide and lower sheave housing (floating swings)
b) Damage on autogauge head
ITEM
a)
Fire fighting system componentsb) c) d) e) f)
C.1.3.2 Tank Piping Manifolds
COMMENTS
Shell plate dimpling around nozzles, caused by excessive pipe deflection c)
Sealing of insulation around manholes and nozzles
e) Adequate manholes flange and cover thickness on mixer manholes
h) Damage on welds on shell-mounted davit clips above valves 6 inches and larger g)
Check for:
d) a) b)
Cracks or signs of leakage on weld joint at nozzles, manholes, and reinforcing plates
C.1.3.1 Manholes and Nozzles
Flange leaks and leaks around bolting
Check for:
TASK
C.1.3 Shell Appurtenances
STATUS
Leaks at piping manifolds, flanges, and valves
Proper operation of regulators for tanks with purge gas systems
Reinforcing pad tell-tale holes are plugged with grease
Check for:
Pass Fail N/A
Pass Fail N/A
Pass Fail N/A
Pass Fail N/A
Pass Fail N/A No access
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
1 1/2" ø galvanized pipe
STATUS COMMENTS
Tape gauge is inoperable
Leaks in circulation pump and operating problems
Inspect condensate drain for presence of oil indicating leakage
Leakage
Bracing and supports for sample water draw-off lines and equipment b)
Check for:
Function of valves and plugging in sample lines, including drain or return-to-tank line c)
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)
a) b)
Proper mounting flange and support
ITEM TASK
h)
Condition of power lines and connections to mixer e) f) g)
Condition of board and legibility of board-type autogauges Freedom of movement of marker and float
Check for:
i)
C.1.3.5 Heater (Shell Manhole Mounted) C.1.3.6 Mixer
C.1.3.3 Autogauge System c) d)
C.1.3.4 Shell-mounted Sample Station Water Draw-Off System a)
39' - 1" (tape); 12' - 1 10/16" (ATG)
Tape gauge is inoperable
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
COMMENTS
Check for leaks at threaded and flanged joints
C.1.3.7 Swing Lines: Winch a) Operation
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
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 C.1.3.9 Swing Lines: Identify Ballast Varying Need
Non-floating: Raise, then lower the swing line with the winch and check for cable lightness to confirm the swing line lowered properly 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
Target should indicate direction of swing opening (up or down) and height above bottom where suction will be lost with swing on bottom support
STATUS
C.1.3.12 Swing Lines: Target
Pass Fail N/A
Pass Fail N/A
Pass Fail N/A
Pass Fail N/A No access
Pass Fail N/A
Coating system is failing and has minor corrosion. Mold and algae on roof
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.)
Handrail toeboard does not allow proper drainage. Toeboard is touching the tank roof at several locations
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.
C.1.4.4 Level of Floating Roof
C.1.4.3 Roof Deck Drainage
ITEM TASK
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.)
C.1.4 Roofs
STATUS
Visually inspect for paint failure, holes, pitting, and corrosion product on the roof deck.
COMMENTS
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.1.4.2 Deck Plate External Corrosion
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
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).
STATUS COMMENTS
No access
C.1.4.7 Floating Roof Seal a) Systems
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.
c) d) e)
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 TASK
C.1.4.6 Roof Insulation b) c)
Crack and leaks in the insulation weather coat where runoff rain water could penetrate the insulation
Check for:
a)
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.
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.
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
No access
Aluminum construction
STATUS
No marker or tab stating hold-off distance
COMMENTS
Operation of systemg)
h) Presence and condition of protective coating or liner inside sample hatch (preventing rust from pipe getting into sample) on ultra clean stocks such as
JP4
a) b) c) d) e) f)
C.1.5.1 Sample Hatch
C.1.4.7 Floating Roof Seal h) Systems
Marker and tab stating hold-off distance, where the sample hatch is used to reel gauge stock level Reinforcing pad where sample hatch pipe penetrates the roof deck.
Operation of recoil reel and condition of rope on floating roof sample hatch and recoil systems i) j)
ITEM TASK
Condition and functioning of sample hatch cover.
Condition of seal inside hatch cover on tanks governed by Air Quality Monitoring District rules Corrosion and plugging on thief and gauge hatch cover.
Inspect wedge-type wiper seals for flexibility, resilience, cracks, and tears.
C.1.5 Roof Appurtenances
Pull both primary and secondary seal systems back all around the shell to check their operation.
Inspect secondary seals for signs of buckling or indications that their angle with the shell is too shallow.
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
Pass Fail N/A
STATUS COMMENTS
No hold-off distance
Valve leakage and for presence of a bull plug or blind flange, if the tank has a gauge well washer
Overall conditions Automatic sealing after sampling, when equipped with a fabric seal
Check for:
Check condition of screens, locking and pivot pins.
Proper operations when equipped with a recoil reel opening device
The distance from the gauge well pipe to the tank shell at different levels, if accessible
C.1.5.5 Autogauge: Float Well Cover
a) Corrosion
Wear or fraying caused by rubbing of the tape cable on the cover b)
Inspect scaffold support for corrosion, wear and structural soundness.
C.1.5.3 Fixed Roof Scaffold Support
C.1.5.4 Autogauge: Inspection Hatch & Guides (Fixed Roof) a)
Check for:
C.1.5.7 Roof-Mounted Vents (Internal Floating Roof)
No access
C.1.5.6 Sample Hatch (Internal Floating Roof) a) b) e)
A hold-off distance marker and tab with hold-off distance (legible) c)
C.1.5.8 Gauging Platform Drip Ring On fixed roof tanks with drip rings under the gauging platform or sampling area, inspect for plugged drain return to the tank.
d) a) b) c)
C.1.5.2 Gauge Well
ITEM TASK
Check for:
Thinning, size of slots, and cover condition of the visible portion of the gauge well
Condition of roof guide for gauge well, particularly the condition of the rollers for grooving on floating roofs
Check for:
b) Corrosion on the tape guide's and flost guide's wire anchors
Corrosion and missing bolts on the hatch
No access
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
No access
Identify and report type (steel pipe, galvanized pipe, square tube, angle) and size of handrails.
Inspect for pitting and holes, paint failure.
Inspect attachment welds.
Identify cold joints and sharp edges.
Inspect the handrails and midrails.
Check for:
ITEM TASK
Report size, number, and type of vacuum breakers. Inspect vacuum breakers. If high legs are set, check for setting of mechanical breaker in high leg position.
2" x 1 1/2" angle for circumferential stairs.
2 1/2" x 2 1/2" angle for roof perimeter handrail
C.1.6 Accessways - See Tank Out-of-Service Inspection Checklist Item C.2.12 b) d)
Test for explosive gas (an indicator of vapor space leaks).
Minor coating failure, mold, and algae growth
a) Condition of the screen on the rim vent cover
b) Plating off or removal of rim vents where jurisdictional rules do not permit removal
C.1.5.13 Pontoon Inspection a) Hatches
Open pontoon inspection hatch covers and visually check inside for pontoon leakage.
C.1.5.9 Emergency Roof Drains
C.1.5.10 Removable Roof Leg Racks
C.1.5.11 Vacuum Breakers
C.1.5.12 Rim Vents
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) If pontoon hatches are equipped with locked down coves, check for vent tubes. Check that vent tubes are not plugged up. Inspect lock-down devices for condition and operation.
STATUS COMMENTS
C.2.12 Access Structures
C.2.12.1 Handrails a) b) c)
Check for leg racks on 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
Pass Fail N/A
Pass Fail N/A
Pass Fail N/A
Pass Fail N/A
Corrosion on platform and grating
Minor corrosion on stair treads
Reinforcing pads where supports are attached to shell or roof.
Check for:
Corrosion, paint failure, and weld failure on spiral stairway stringers c)
Inspect the handrail between the rolling ladder and the gauging platform for a hazardous opening when the floating roof is at its lowest level.
Check for:
ITEM TASK
Welded
Stair treads welded directly to shell a) c) d)
Corrosion-caused thinning of bars and failure of welds on grating Grating tie down clips. Where grating has been retrofitted to replace plate, measure the rise of the step below and above the grating surface and compare with other risers on the stairway.
C.2.12.4 Stairway Stringers
Check for:
Corrosion-caused thinning or holes (not drain holes) and paint failure on the deck plate
Inspect safety drop bar (or safety chain) for corrosion, functioning, and length.
Minor corrosion on deck grating
e) Seal-weld on flat surface–to-flat surface junctures
Corrosion and paint failure on frame Corrosion and weld failure on the…
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