ATT D - ROB-FY15-FAC 4302-Tank 23-FINAL.pdf

TANK 4302 (TANK 23)

API 653 IN-SERVICE INSPECTION REPORT

Robins AFB, Georgia

A/E Contract No. W9128F-12-D-0006; Delivery Order No. 0006

Submitted to:

U.S. Army Corps of Engineers Omaha District

1616 Capital Avenue; Omaha, NE 68102

6 May 2015

Submitted by:

1011 Boulder Springs Drive, Suite 200; Richmond, Virginia 23225 Phone: 804.592.3900 Fax: 804.592.3901 www.brockenbrough.com Job No. 14-101.11

Austin Brockenbrough & Associates, LLP | Est. 1955

1011 Boulder Springs Drive, Suite 200 | Richmond, Virginia 23225 | 804.592.3900 main | 804.592.3901 fax www.brockenbrough.com

Adam Ashton

U.S. Army Corps of Engineers

Omaha District

1616 Capital Avenue

Omaha, Nebraska, 68102

Re: Inspection Report – Tank 4302 (Tank 23), Robins AFB, GA

USACE Omaha Contract No. W9128F-12-D-0006 D.O. 0006

Brockenbrough Job No. 14-101.11 API 653 In-service Tank Inspections

Various CONUS Locations

Dear Mr. Ashton:

On March 23rd, 2015, personnel from Austin Brockenbrough & Associates, LLP

(Brockenbrough) performed an API 653 In-service (Visual External) Inspection of Tank 4302

(AKA Tank 23) located at Robins Air Force Base, Georgia. The In-service Inspection of the nominal 88,000 bbl, 112 feet and 3 inches in diameter by 52 feet and 3 inches tall, F-24 (Jet-

AA), aboveground vertical storage tank 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.

The tank’s previous inpection reports indicate that the tank was built in the 1980s. However, the tank data plate is missing from the tank shell. Leak detection is provided by leak detection ports projecting through the tank’s ringwall foundation. The underside of the tank bottom is protected by an impressed current cathodic protection system. The tank’s roof is accessible by a circumferential stairway mounted on the shell of the tank. As-built drawings of the original construction were not available at the time of the inspection. The tank underwent repairs and upgrades in 2009 and 2010. The stencil on the tank shell and shell manhole cover indicates the tank was last cleaned and inspected in May of 2009. During this inspection several repairs and upgrades to the tank occurred. The repairs performed on the tank are indicated in the Out-of-

Service Inspection Report which is dated November 2010.

Jet-AA fuel is received into the 88,000 bbl tank from bulk via an underground pipeline through the facility’s filter/separators and is issued from the tank through filters/separators to a truck fillstand and a hydrant system.

A list of the tank’s general construction features is included on page 2.

Tank 4302 (Tank 23) General Construction Data

Item Description

Owner U.S. Air Force

Tank Identification 4302 (Bulk Tank 23)

Location Robins AFB, Warner-Robins, Georgia

Manufacturer Unknown

Design Standard API Standard 650, 8th Edition (assumed).

Year Built 1980s (Based on previous inspection reports.)

Current Product Stored Jet-AA (F-24) jet fuel, specific gravity: 0.775 to 0.840, true vapor pressure: 0.04 psia at 100F, flash point: 100-150F, viscosity:

1.6 x 10-5 ft2/s at 100F, Class II combustible liquid.

Dimensions 112’-3” diameter x 52’-3” shell (straight side) height.

Storage Capacity Nominal capacity = 88k bbl. (Per 2010 Inspection and Repair

Report)

Cleaning, Inspection, or

Repair

Cleaned, repaired and inspected in 2009 and 2010.

Foundation Concrete ringwall.

RPB/Leak Detection None (Per 2010 Inspection and Repair Report)

Bottom Construction Lap welded cone-down (assumed)

Shell Construction (6) butt-welded shell courses, carbon steel plate; rim angle leg-out butt welded to shell.

Fixed Roof Construction Lap-welded steel plate, cone up, self-supporting.

Stairs/Ladders Circumferential stairway; interior vertical ladder.

Manholes (3) 36” shell manholes, (2) lower and (1) upper;

(1) 24” flush cleanout

Cathodic Protection Impressed Current.

Interior Coating System Epoxy-Epoxy-Epoxy (assumed).

Exterior Coating System Zn/Epoxy-Epoxy-Polyurethane (assumed).

Level Gauging Shand and Jurs Tape Level Gauge and Enraf ATG

Overfill Protection/Level

Alarms

Shell mounted high-high and high, level alarms; hydraulic operated level control valve.

Piping 8” receipt, 8” issue, 4” low suction, 3/4” water draw-off.

Venting/Vapor Emission

Controls

Internal floating pan, open 24” center vent on roof; (6) roof mounted perimeter circulation vents, (2) shell mounted overflow vents.

Strapping Tables Strapping tables are available.

Water Draw-Off/Product

Recover System

Product saver tank. Water draw-off piping equipped with isolation valve and quick disconnect coupler.

Secondary Containment Concrete dike walls.

Fire Protection System AFFF and several fire hydrants within vicinity.

The results of the inspection are included with the Tank In-Service Inspection Checklist starting on page 6. A checkmark beside an item indicates it was examined and no deficiency was noted.

An “X” beside a checklist item indicates a deficiency and a comment/note is made. During this evaluation, the tank was found to be in a generally good and acceptable condition. There were several anomalies or deficiencies noted, most of which are included on the checklist. These deficiencies, and recommendations for addressing them, are noted below in no particular order:

1. The tank does not have a nameplate. The following action should be taken to correct the deficiency:

Provide a new tank data nameplate.

Estimated construction cost is $5,000.

2. As shown in Photograph #1 on page 13, there are unsealed hairline cracks on the concrete ringwall foundation. The following action should be taken to correct the deficiency:

Seal the hairline cracks in the foundation ringwall.

Estimated construction cost is $10,000.

3. There are plants and organic material (such as dirt, debris, etc.) within the dike area. There are several areas where plants are growing through the dike floor seals at the dike wall and tank ringwall interfaces. See Photograph #2 on page 13. The following actions should be taken to correct the deficiency:

a) Remove plants and organic material from dike area and dike floor seals.

b) Spot repair the dike floor seals.

Estimated construction cost is $10,000.

4. As shown in the photographs following the checklist, and especially in Photograph #3 on page 14, mold and algae are growing on the exterior of the tank and concrete foundation.

The following actions should be taken to correct this deficiency:

a) Power wash the tank foundation, the exterior of the tank and the tank appurtenances.

b) Coat the tank foundation, exterior of the tank and appurtenances with an anti-fungal/algaecide.

Estimated construction cost is $30,000.

5. The tank bottom-to-foundation seal has failed in several places. See Photograph #4 on page

14. The following action should be taken to correct the deficiency:

Spot repair the tank bottom-to-foundation seal.

Estimated construction cost is $10,000.

6. The mechanical tape gauge is not calibrated correctly. The readings from the mechanical tape gauge and the automatic tank gauging (ATG) system differ greatly. The following action should be taken to correct the deficiency:

Recalibrate the mechanical tape gauge.

Estimated construction cost is $5,000.

7. There are several areas of general and localized coating failure and minor surface corrosion on the manhole access platforms, tank anchors, roof, roof nozzles and appurtenances, the circumferential stairway handrails and stair treads, and platform gratings. See Photographs

#5 through #10 on pages 15, 16, and 17. The following action should be taken to correct these deficiencies:

Spot repair the areas of coating failure on the exterior of the tank, the nozzles and appurtenances.

Estimated construction cost is $55,000.

8. During our inspection, it was observed that there are several areas on the tank roof with standing water. See Photograph #11 on page 18. The majority of these areas are located near the outer perimeter of the tank roof. Standing water on tank roofs can accelerate coating failure and create corrosion on the steel plates. Coating failure and moderate surface corrosion and pitting was observed at some of these locations. The following actions should occur to correct this deficiency:

a) Conduct further study on extent of roof plate pitting that has occurred at these locations.

b) If required, repair roof plates.

c) Spot repair coating system at these locations.

d) Routinely monitor and inspect areas on the roof where water ponds for coating failure and corrosion.

Estimated construction cost is $50,000.

9. As shown in Photograph #12 on page 18, the water draw-off system piping and tank nozzle are threaded. Military standards do not allow threaded piping or nozzles to be used. Also, the tank isolation valve is a ball valve. Military standards require tank isolation valves to be double block and bleed valves. The following actions should be taken to correct these deficiencies:

a) Replace the threaded water draw-off nozzle with a flanged nozzle the next time the tank is taken out of service.

b) Replace the threaded pipe with welded pipe and flanged valves and equipment.

c) If the threaded connections are replaced with flanges, replace water draw-off tank isolation valve with a double block and bleed isolation valve.

Estimated construction cost is $30,000.

10. The thermal relief valve assemblies installed on the tank issue and receipt piping are constructed of threaded pipe. UFC 3-460-01 states to “use threaded connections only where unavoidable…” The thermal relief valve assemblies also do not have testing tees as required by the UFC. See Photograph 13 on page 19. The following action should be taken to correct these deficiencies:

Provide welded or flanged connections and testing tees on the thermal relief piping.

Estimated construction cost is $10,000.

11. It was observed that some of the latches for the inspection hatches do not function properly.

Some of the latches have been painted over and/or corroded to the point where operation is difficult. The following action should be taken to correct this deficiency:

Repair latches to proper working order.

Estimated construction cost is $5,000.

12. As indicated in Photograph #14 on page 19, the attachment corner weld of the shell stiffener and roof angle could be subjected to high concentrations of stress during tank movement and could fail and/or cause damage to the tank. It should be noted, that the shell stiffeners on

Tank 24 have been modified to eliminate this corner weld. However, at the time of our inspection, all visible welds at these areas appeared to be in good condition. The following action should be taken to correct this deficiency:

Routinely monitor and inspect the weld seams on each of the stiffener plates to the tank shell for cracking and failures. Inspection should include all weld seams, however, special attention should be given at the corner weld where the stiffeners are attached to the roof angle.

Estimated construction cost is $0.

All repairs and modifications should be performed in accordance with API 653, UFC 3-460-01, DoD Standard Design 78-24-27, and applicable UFGS specifications.

The estimated construction costs noted above are based upon all of the work being performed under a single construction contract. The costs do not include any special conditions or prime contractor markup that might be applicable, but they do include the cost of any coating repairs that would be required due to the contractor’s work. The total estimated cost for all the recommended repairs is $210,000.

TANK INSPECTION, REPAIR, ALTERATION, AND RECONSTRUCTION

Tank In-service Inspection Checklist

Item Completed Comments

C.1.1 Foundation

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

C.1.1.1 Concrete Ring a)

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

X See notes.

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.

NA

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

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

C.1.1.4 Rock

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

NA

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

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

C.1.1.7 Cathodic Protection

Review cathodic protection potential readings. X See notes.

C.1.2 Shells

C.1.2.1 External Visual Inspection

a) Visually inspect for paint failures, pitting, and corrosion. X See notes.

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

c) Inspect the bottom-to-foundation seal, if any. X See notes.

C.1.2.2 Internal (Floating Roof Tank)

Visually inspect for grooving , corrosion, pitting, and coating failures No access.

C.1.2.3 Riveted Shell Inspection

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

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

c) Inspect rivets for corrosion loss and wear. NA

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

Tank In-service Inspection Checklist (Continued)

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)/Shell Stiffeners

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. No repads.

C.1.3 Shell Appurtenances

C.1.3.1 Manholes and Nozzles

a) Inspect for cracks or signs of leakage on weld joint at nozzles, manholes, 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 manholes and nozzles. NA

e) Check for inadequate manhole flange and cover thickness on mixer manholes. NA

C.1.3.2 Tank Piping Manifolds

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

b) Inspect firefighting 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. X See notes.

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

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

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

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

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). No access.

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.). X See notes.

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

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

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

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. NA

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

c) Test bracing and supports for sample tines and equipment. NA

C.1.3.5 Heater (Shell Manhole Mounted)

Inspect condensate drain for presence of oil indicating leakage. NA

C.1.3.6 Mixer

a) Inspect for proper mounting flange and support. NA

b) Inspect for leakage. NA

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

C.1.3.7 Swing Lines: Winch Operation

a) Nonfloating. Raise, then lower the swing line with the winch, and check for cable lightness 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 light, 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.

NA

C.1.3.8 Swing Lines: External Guide System

Check for leaks at threaded and flanged joints NA

C.1.3.9 Swing Lines: Identify Ballast Varying Need

Check for significant difference in stock specific gravity. NA

C.1.3.10 Swing Lines: Cable Material and Condition

a) For nonstainless steel cable, check for corrosion over entire length. NA

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

C.1.3.11 Swing Lines: Product Sample Comparison

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

C.1.3.12 Swing Lines: Target

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

NA

C.1.4 Roofs

C.1.4.1 Deck Plate Internal Corrosion

For safety, before accessing the roof, check with ultrasonic instrument or lightly use a ball peen hammer to test the deck plate near the edge of the roof for thinning. (Corrosion normally attacks the deck plate at the edge of a fixed roof and at the rafters in the center of the roof first.)

C.1.4.2 Deck Plate External Corrosion

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

C.1.4.3 Roof Deck Drainage

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

X See notes.

C.1.4.4 Level of Floating Roof

At several locations, measure distance (inches) from floating roof rim to the horizontal weld seam above the roof or fixed roof inspection hatch openings. A variance in the readings indicates a non-level roof with possible shell out-of-round, out-of-plumb, leaking pontoons, or hang-up. On small diameter tanks, an un-level condition can indicate unequal loading at that level.

X

Floating Pan too low to get accurate measurement.

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.

0.0 ppm on pan.

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. NA

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).

No access.

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

1) ______ Opposite pair 1.

2) ______ Opposite pair 2.

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

No access.

d) Inspect fabric for deterioration, holes, tears, and cracks. No access.

e) Inspect visible metallic parts for corrosion and wear No access.

f) Inspect for openings in seals that would permit vapor emissions. No access.

g) Inspect for protruding bolt or rivet heads against the shell. No access.

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.

No access.

j) Inspect wedge-type wiper seals for flexibility, resilience, cracks, and tears. No access.

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. NA

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

g) Test operation of system. NA

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). Aluminum

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 a 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.

NA

C.1.5.3 Fixed Roof Scaffold Support

Inspect scaffold support for corrosion, wear and structural soundess. NA

C.1.5.4 Autogauge: Inspection Hatch and guides (Fixed Roof)

a) Check the hatch for corrosion and missing bolts.

b) Look for corrosion on the tape guide's and float guide's wire anchors. No access.

C.1.5.5 Autogauge: Float Well Cover

a) Inspect for corrosion. No access.

b) Check tape cable for wear or fraying caused by rubbing on the cover. No access.

C.1.5.6 Sample Hatch (Internal Floating Roof)

a) Check overall conditions. No access.

b) When equipped with a fabric seal, check for automatic sealing after sampling. No access.

c) When equipped with a recoil reel opening device, check for proper operations. No access.

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

Check condition of screens, locking and pivot pins.

C.1.5.8 Gauging Platform Drip Ring

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

C.1.5.9 Emergency Roof Drains

Inspect vapor plugs for emergency drain: that seal fabric discs are slightly smaller than the pipe 10 and that fabric seal Is above the liquid level.

NA

C.1.5.10 Removable Roof Leg Racks

Check for leg racks on roof. NA

C.1.5.11 Vacuum Breakers

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

No access.

C.1.5.12 Rim Vents

a) Check condition of the screen on the rim vent cover. No access.

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

No access.

C.1.5.13 Pontoon Inspection Hatches

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

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

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.

NA

C.1.6 Accessways (See Tank Out-of-service Inspection Checklist, Item C.2.12.)

C.2.12 Access Structures

C.2.12.1 Handrails

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

b) Inspect for pitting and holes, paint failure. X See notes.

c) Inspect attachment welds.

d) Identify cold joints and sharp edges. Inspect the handrails and mid-rails.

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

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

NA

C.2.12.2 Platform Frame

a) Inspect frame for corrosion and paint failure.

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

c) Check reinforcing pads where supports are attached to shell or roof. NA No repads.

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

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

C.2.12.3 Deck Plate and Grating

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

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

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

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

NA

C.2.12.4 Stairway Stringers

a) Inspect spiral stairway stringers for corrosion, paint failure, and weld failure. X See notes.

b) Inspect stairway supports to shell welds and reinforcing pads. No repads.

c) Inspect steel support attachment to concrete base for corrosion. NA

C.2.12.5 Rolling Ladder

a) Inspect rolling ladder stringers for corrosion. NA

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

NA

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

d) Inspect pivot bar for wear and that it is secure. NA

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

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

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

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

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

NA

j) Inspect rolling ladder track welds for corrosion. NA

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

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

Max. angle ______________.

m) If rolling ladder track extends to within 5 ft of the edge of the roof on the far side, check for a handrail on the top of the shell on that side.

NOTES:

C.1.1 The foundation measurements indicate the tank is relatively level and with no appreciable out-of-plane deflection. No limit of planer tilt is stated in API 653. The distance measured from the tank bottom external extension to a horizontal level line at 12 equal distant locations were: 19 9/16” (origin), 19 5/8”, 19", 18 7/8” (low point), 19 3/16”, 19 5/16”, 19 9/16”, 19 5/8”, 19 11/16”, 19 1/2", 20 1/16”, 19 9/16””, and 19 9/16” (origin). The tank measures level to within 7/8” inch in 112’-3”. Calculations evaluating the shell settlement are attached.

C.1.1.1.a) Minor hairline cracks in ringwall at several locations.

C.1.1.6 Vegetation and algae build up within dike area. Plants growing through dike seals at ringwall to dike floor interface and dike wall to floor interface.

C.1.1.7 Cathodic protection test station not working during inspection. Power to cathodic protection system and other electrical components has been temporarily interrupted due to a construction project within vicinity of fuel farm.

Personnel indicated CP system works properly.

C.1.2.1.a) Mold and algae growing on tank roof, shell, appurtenances and concrete foundation. Coating failure at several locations on tank shell near tank bottom. Coating failure and surface corrosion on square tank anchor brackets/washers.

C.1.2.1.c) Tank bottom-to-foundation seal has failed in several locations around the tank.

C.1.3.2.d) The thermal relief valve piping is threaded and has no testing tees.

C.1.3.3.f) Mechanical Tape Gauge = 14’-8”; ATG=13’-1”.

C.1.4.2 Isolated coating failures and surface corrosion on tank roof plates. Light coating failure and corrosion on center vent birdscreen. Coating failure on circulation vents and roof perimeter handrails.

C.1.4.3 Standing water at several locations on tank roof. Minor coating failures and corrosion was observed at some locations. Moderate corrosion and pitting was observed near first inspection hatch located counter clockwise from stair platform.

C.2.12.1.a) Handrail on circumferential stairway is 1 3/4” diameter steel pipe and handrail around perimeter of the roof is 2”x2” steel angle.

C.2.12.1.b) Coating failure and light surface corrosion at several areas on the circumferential stair and roof perimeter handrail systems.

C.2.12.3.a) and C.2.12.4.a) Minor coating failures and surface corrosion on circumferential stairway treads and platform grating and platform support frames.

ADDITIONAL NOTES:

Mold/Algae growth on shell, stairs, and roof.

Water draw-off system piping and tank nozzle are threaded. Associated tank isolation valve is a ball valve.

The coating system on the manhole access platforms (framing, handrails, grating, etc.) have failed. Moderate surface corrosion present at failed coating locations.

Storage tank does not have a nameplate.

Two of the Inspection hatch latches are inoperable (corroded and painted over). Unable to open latches.

Corner weld where the shell stiffeners and roof angle weld meet.

Photograph #1 – Concrete Ringwall Foundation

There are hairline cracks in concrete ringwall that need to be sealed.

Photograph #2 – Plants and Vegetation in Dike Area

There are plants and vegetation growing in dike containment area.

Plants have penetrated dike seals in several locations.

Photograph #3 – Mold and Algae on Tank

Mold and algae growth on tank roof, shell, and tank appurtenances.

Photograph #4 – Tank Bottom-to-Foundation Seal

The tank bottom-to-foundation seal has failed in several locations around the tank.

Photograph #5 – Gauge Well

Coating failure and surface corrosion on gauge well and other appurtenances.

Photograph #6 – Tank Roof Plates General coating failures and surface corrosion on tank roof.

Photograph #7 – Circumferential Stair Handrail

General coating failure and surface corrosion on handrails.

Photograph #8 – Circumferential Stair Treads

General coating failure and surface corrosion on tank stair treads.

Photograph #9 – Tank Perimeter Railing System

Coating failure and surface corrosion on tank perimeter railing system.

Photograph #10 – Tank Anchors

General coating failure and corrosion on tank anchors.

Photograph #11 – Standing Water on Tank Roof

Standing water at several locations on the tank roof were observed. Coating failure and moderate corrosion/pitting was present at some of these locations.

Photograph #12 – Water Draw-Off System

Water draw-off system piping and tank nozzle is threaded. Tank isolation valve is a ball valve.

Photograph #13 – 8-inch Receipt Piping

Thermal relief piping is threaded and they do not have testing tees.

Photograph #14 – Vertical Shell Stiffeners

Corner weld at shell stiffener plate and roof angle.

g:\14 jobs\14-101 api 653 in-service inspections\14-101.11 api 653 inspections - robins afb\general\reports\final\tank 4302 (23)\report - tank 4302

(23) robins afb.docx

While this In-Service (Visual External) Inspection found no problems requiring immediate repair and the accessible areas of the tank appear suitable for continued use in its current service, there are some deficiencies that are contrary to API 650, NFPA 30, and OSHA. These deficiencies should be addressed in a timely manner.

The next API Standard 653 In-Service (Visual External) Inspection should be performed by an

API 653 Inspector by March 2020. The inspection may be performed in conjunction with the next out-of-service inspection if performed before that date.

The 2009 Out-of-Service Inspection Report recommends Ultrasonic thickness measurements

(UTMs) of the shell to have been performed by 2014 and conducted during the In-Service

Inspection. UTMs were not conducted on the tank shells and were not included as part of our scope of work for this project. Since UTMs of the tank shell were not performed during this inspection, it is recommended that they be performed in conjunction with the next Out-of-

Service Inspection.

The 2009 Out-of-Service Inspection Report recommends an API 653 Out-of-Service (internal)

Inspection be performed by 2019. The Out-of-Service (internal) Inspection should include examination of the tank bottom by magnetic flux leakage (MFL or MFE) technology and an evaluation of the cathodic protection system.

The Out-of-Service Inspection should include a thorough code compliance evaluation. The code compliance evaluation should include 29 CFR Part 1910.106, Occupational Safety and Health

Standards – Flammable and Combustible Liquids; 29 CFR Part 1910 Subpart D, Occupational

Safety and Health Standards – Walking-Working Surfaces; 40 CFR Part 112, Oil Pollution

Prevention; NFPA 30, Flammable and Combustible Liquids Code; and UFC 3-460-01, Design:

Petroleum Fuel Facilities.

Please contact us if you have any questions or need more information.

Sincerely, Austin Brockenbrough & Associates, LLP

Jeffrey W. King, PE

Mechanical Engineer

API 653 Inspector No. 54102

STI SP001 Inspector No. AC 44062

Enclosures:

Tank Settlement Evaluation

Austin Brockenbrough & Associates, L.L.P. Job No. 14-101.11

Job Title: Robins AFB Date: 3/31/2015

Subject: Tank 4302 (Tank 23) By: Jeffrey King

API 653 Appendix B

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

Diameter (D) = 112.25 (ft)

Number of equally spaced data points (ft)= 12

L = Arc length between measurement points (ft) = 29.39

Tank Height (H) = 52.3 (ft)

* Z U S

0 18.88 0.00 0.19 0.19 0.17

1 19.19 0.31 0.24 -0.07 -0.14

2 19.31 0.44 0.38 -0.06 0.04

3 19.56 0.69 0.57 -0.11 -0.09

4 19.63 0.75 0.76 0.01 0.03

5 19.69 0.81 0.90 0.09 -0.08

6 19.50 0.63 0.95 0.33 0.43

7 20.06 1.19 0.90 -0.28 -0.49

8 19.56 0.69 0.76 0.08 0.28

9 19.56 0.69 0.57 -0.11 0.03

10 19.63 0.75 0.38 -0.37 -0.37

11 19.00 0.13 0.24 0.12 0.21

12 18.88 0.00 0.19 0.19 0.17

Maximum out-of -plane deflection = 0.49

* = measured elevation

Z = calculated ridged body tilt (in)

U = out-of-plane settlement =

S = out-of-plane deflection z-y

Y = yield sterength of shell material (PSI) = 30,000

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

S allowable (in) (API 653 B.3.2.1) = (L^2*Y*11)/(2EH)*12 = 1.13 in

R^2 = (Syy - SSE) / Syy = 0.8 not >=0.9 therefore cosine curve is invalid.

Evaluation by the Arc Length Method is required.

Austin Brockenbrough & Associates, L.L.P. Job No. 14-101.11

Job Title: Robins AFB Date: 3/31/2015

Subject: Tank 4302 (Tank 23) By: Jeffrey King

API 653 B.2.2.5 Evaluation by Settlement Arc Length Method

Per B.3.2.2, K = 3.9

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

0 205.7 0.8 1.78 OK

6 58.8 0.4 0.51 OK

8 88.2 0.4 0.76 OK

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

0.00

0.50

1.00

1.50

0 2 4 6 8 10 12 14

Measured Elevation (in)

Si6

Si0 Si8