Attachment J ROB-FY15-FAC 4236-Tank 22-FINAL_Redacted.pdf

TANK 4236 (TANK 22)

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

13 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 4236 (Tank 22), 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 25th, 2015, personnel from Austin Brockenbrough & Associates, LLP

(Brockenbrough) performed an API 653 In-service (visual external) Inspection of Tank 4236

(AKA Tank 22) located at Robins Air Force Base, Georgia. The In-service Inspection of the nominal 25,000 bbl, 62 feet in diameter by 52 feet tall, diesel, 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 was out-of-service at the time of inspection for repairs due to leaking distribution piping.

The tank does not have a name data plate, but the previous out-of-service inspection report states that the tank was constructed sometime in the 1980s. There are no means of leak detection around the tank, but tracer ports are provided along the underground piping from the tank. The underside of the tank bottom is protected by a sacrificial anode 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 was last cleaned and out-of-service inspected in August of 2009. Repairs were completed in

August of 2010.

Diesel fuel is received into the 25,000 bbl tank via truck fillstand. The tank supplies back to the fillstand and also connects to a transfer pump which issues fuel to the nearby steam generation plant and Building 181 through an underground pipeline.

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

b) Seal the sample hatch reinforcing plate weep hole.

c) Replace the entire roof and roof appurtenance coating.

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

Estimated construction cost is

5. Coating buildup on the roof center vent screen has caused some of the vent to be blocked.

The following action should be taken to correct this deficiency:

Replace roof center vent screen.

Estimated construction cost is

6. The water draw-off system piping and tank nozzle are threaded and uncoated. 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:

At the next out-of-service inspection:

a) Replace the threaded water draw-off nozzle with a flanged nozzle.

b) Replace water draw-off system tank isolation valve with a double block and bleed isolation valve.

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

d) Provide new coating system on water draw-off system piping.

Estimated construction cost is

7. The thermal relief valve assembly installed on the tank issue piping is constructed of uncoated threaded pipe. UFC 3-460-01 states to “use threaded connections only where unavoidable…” The thermal relief valve assembly also does not have testing tees as required by the UFC. The thermal relief assemblies also contain sight flow indicators. Sight flow indicators are known leak points and are prohibited on thermal relief piping per the UFC.

The following actions should be taken to correct these deficiencies:

a) Remove the sight flow indicators from the thermal relief piping.

b) At the next out-of-service inspection, provide welded or flanged connections and testing tees on the thermal relief piping.

c) Provide new coating system on all thermal relief piping.

Estimated construction cost is

8. The risers of the circumferential stairway measure approximately 9”. However, the distance from the concrete containment slab to the top of the lowest stair tread measures approximately 7 3/4". OSHA requires a consistent rise and run over the entire stairway. The following action should be taken to correct this deficiency:

Install a landing at approximately 7 3/4" above slab.

Estimated construction cost is

9. The secondary containment area has a few places that show signs of deterioration and collection of debris. The containment slab is cracking in some areas. The joint sealants have also failed throughout the area. Where water is ponding, there is some minor vegetation growth taking place. A hole in the concrete berm wall has allowed vegetation to grow out of the wall. There is also an area in the berm where the wire mesh reinforcement is exposed.

The seal between the containment slab and the tank foundation has also begun to fail.

Conduit running through the containment area rests directly on the slab without any supports to raise it to allow for drainage and protection from sitting in standing water. See

Photographs #11 through #13 on pages 19 and 20. The following actions should be taken to correct these deficiencies:

a) Remove debris and vegetation.

b) Repair areas where slab has cracked.

c) Replace joint sealants in the slab and at the slab-to-tank foundation interface.

d) Raise and support the conduit off of the containment slab.

e) Patch the hole in the concrete berm wall.

f) Patch the wall area where the mesh reinforcement is exposed.

Estimated construction cost is

10. While the tank was not entered for this inspection, it was noticed that the internal floating pontoon shows signs of moisture collection on the topside and scattered surface corrosion.

The roof support structure also displays some corrosion. The previous out-of-service report photos show the tank bottom is experiencing some light surface corrosion and is not coated.

See Photograph #14 to #15 on pages 20 and 21. UFC 3-460-01 requires the floor, underside of the fixed roof, and the bottom 40 inches of the tank shell to be coated for all non-aviation and non-diesel fuel marine tanks. The following actions should be taken to correct these deficiencies:

At the next out-of-service inspection, clean and coat the tank floor, the underside of the fixed roof (including the support structure), and the bottom 40 inches of the tank shell.

Estimated construction cost is

11. The automated tank gauge (ATG) does not have slots along its length. ATG wells are required to be slotted. The following action should be taken to correct this deficiency:

At the next out-of-service inspection, slot the ATG well.

Estimated construction cost is

12. The mechanical tape gauge read 17’-5 1/4" while the ATG read 17’-8 6/16” at the time of inspection. The mechanical tape gauge is inaccurate by more than what is acceptable. The following action should be taken to correct this deficiency:

Recalibrate the tape gauge.

Estimated construction cost is

13. The flexible connectors on the piping from the tank allow for slight variations in movement of the piping to prevent overstressing the pipe and the tank shell. The flexible connector on the 6-inch issue line is coated solid, restricting its functionality. See Photograph #16 on page

21. The following action should be taken to correct this deficiency:

At the next out-of-service inspection, replace the flexible connector.

Estimated construction cost is

14. The low manhole reinforcing plate’s weep hole displays a leak, presumably in the manhole weld. See Photograph #17 on page 22. Base personnel indicated that this has occurred in the past with repairs and replacements made to the manhole. The fuel was low at the time of inspection, but with higher fuel levels and high pressures, the leak could worsen. Other weep holes around the tank are clogged, preventing leak detection. The following actions should be taken to correct this deficiency:

At the next out-of-service inspection:

a) Replace the manhole and reinforcing plate.

b) Provide new coating system for the manhole and reinforcing plate.

c) Unplug all weep holes.

Since the tank is currently not in service and to prevent further leaking, these repairs could be completed immediately. Estimated construction cost is

All repairs and modifications should be performed in accordance with API 653, UFC 3-460-01, DoD Standard Design AW 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

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. X See notes.

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.

X See notes.

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 NA

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)

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.

NA

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

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

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.

X See notes.

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. NA

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

X See notes.

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 he 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.). 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. No access.

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.)

No access.

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 poss ble leaking pontoons.)

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 poss ble 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.

No access. See notes.

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.

1.5 & 1.4 ppm VOC 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 flex bility, 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. X See notes.

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. 51’-10 1/4"

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

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

g) Test operation of system. No access.

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. Slotted.

b) Check for a hold-off distance marker and tab with a hold-off distance (leg ble). X See notes.

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.

No access.

C.1.5.3 Fixed Roof Scaffold Support

Inspect scaffold support for corrosion, wear and structural soundess.

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.

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. X See notes.

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.

NA

C.1.5.13 Pontoon Inspection Hatches

a) Open pontoon inspection hatch covers and visually check inside for leakage. No access.

b) Test for explosive gas (an indicator of vapor space leaks). No access.

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.

No access.

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. X See notes.

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.

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.

b) Inspect stairway supports to shell welds and reinforcing pads.

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 8 equal distant locations were: 71 3/16” (origin), 70 13/16”, 70 5/8" (low point), 71 1/16", 70 15/16”, 71 3/16”, 71 1/8”, 71”, and 71 3/16” (origin). The tank measures level to within 1/2” in 62’-0”. Calculations evaluating the shell settlement are attached.

C.1.1.1.a) Cracks around perimeter in the top of the exposed concrete ringwall.

C.1.1.1.c) Vegetation (moss, weeds, etc.) growing from failures in seal at the tank bottom.

C.1.1.6 Dead bird, dirt, rocks, and some broken concrete laying around in dike area.

C.1.1.7 Sacrificial anode cathodic protection.

C.1.2.1.a) Minor isolated coating failure and corrosion on tank shell and manholes.

C.1.2.1.b) Minor isolated coating failure and corrosion on tank bottom plate extension.

C.1.2.1.c) Tank bottom-to-foundation seal failure around tank allowing vegetation growth.

C.1.3.1.a) Fuel leaking out of weep hole in low manhole reinforcing plate. Other weep holes are clogged. Minor surface corrosion on reinforcing plates and plate welds.

C.1.3.2.c) Flexible connector on the 6” issue pipe is coated.

C.1.3.2.d) Thermal relief piping is threaded and uncoated at all locations. No testing tees.

C.1.3.3.f) Tape Reading = 17’-5 1/4”; ATG = 17’-8 6/16”.

C.1.4.2 Coating failure and surface corrosion in several locations on tank roof plates and more substantially on roof plate welds.

C.1.4.3 Locations of standing water indicate poor drainage. Coating failure and corrosion present at some of these locations.

C.1.4.4 Floating pan too low to measure from roof.

C.1.5.1.a) Coating failure and corrosion on sample hatch.

C.1.5.1.e) Coating failure and corrosion on reinforcing plate. Corrosion around weep hole in plate.

C.1.5.2.b) No hold-off distance marked on or near gauge well.

C.1.5.7 Coating failure and corrosion around roof vents where water pools. Center roof vent screen is partially blocked with coating.

C.2.12.1.a) 2”x2” angle handrails and 1/2"x1/2” rod supporting stairs.

C.2.12.1.b) Coating failure and corrosion on handrails at stairs and on roof.

C.2.12.2.a) Coating failure and corrosion on platform support frame.

C.2.12.2.b) Coating failure and corrosion on reinforcing plate to shell welds for platform frame.

C.2.12.3.a) Coating failure and corrosion on both deck plate and grating on stairs and platforms.

ADDITIONAL NOTES:

Wire mesh reinforcement exposed in concrete dike berm wall.

Coating failure and corrosion on high level alarm flanges and bolts.

Conduit in dike area rests directly on the containment slab.

Vegetation in the standing water in the containment area.

Concrete broken at the dike access stair.

Coating failure and corrosion on some of the piping coming from the tank.

Containment slab cracked and joints and joint sealants failing.

Containment slab experiencing minor differential settlement.

Tank bottom plate extension varies in size.

Most flanges and bolts corroded.

Hole in concrete dike berm wall with vegetation growing.

Corrosion on the roof support structure and on the internal floating pontoon.

Minor corrosion on the exterior of the automatic gauge well inside the tank.

Water draw-off piping and nozzle are threaded. Water draw-off tank nozzle is 3/4" and is a ball valve.

Non-OSHA compliant first and last step on circumferential stair. Average rise = 9”, First rise = 7 1/2”, Last rise = 11 3/4"

Photograph #1 – Concrete Ringwall Cracking

Large cracks and spalling in concrete ringwall.

Photograph #2 – Bottom-to-foundation Seal

Seal failure around tank bottom and vegetation growth.

Photograph #3 – Stair Access Platform Coating failure and corrosion.

Photograph #4 – Tank Manhole

Photograph #5 – High, High-High Level Alarm

Coating failure and corrosion

Photograph #6 – Access Stair Support Frame

Photograph #7 – Stair Grating

Photograph #8 – Roof

Photograph #9 – Roof Near Roof-Mounted Vent

Standing water, coating failure, and corrosion.

Photograph #10 – Roof Plate Weld

Standing water, coating failure, and corrosion.

Photograph #11 – Containment Slab

Crack and concrete spall in slab.

Photograph #12 – Berm Wall

Hole and vegetation in wall.

Photograph #13 – Berm Wall

Wire mesh reinforcement exposed.

Photograph #14 – Floating Steel Pontoon

Signs of moisture collection and light corrosion.

Photograph #15 – Roof Support Structure

Corrosion on the roof structure.

Photograph #16 – Pipe Flexible Connector

Coating has reduced the movement of the connector.

Photograph #17 – Low Manhole Weep Hole

Leak at the low manhole.

g:\14 jobs\14-101 api 653 in-service inspections\14-101.11 api 653 inspections - robins afb\general\reports\final\tank 4236 (22)\report letter -tank 4236 (22) robins afb.docx

Due to the tank being out-of-service, the lower manhole requiring replacement, and internal deficiencies to be addressed, we recommend performing the repairs immediately.

According to the previous inspection report, the last out-of-service was performed in August of

2009, and the next out-of-service inspection should be performed within 10 years of the date

(August 2019). However, an out-of-service inspection could be performed if repairs are completed immediately. The next API Standard 653 In-Service (visual external) Inspection should be performed by an API 653 Inspector by March 2020.

The Out-of-Service (internal) Inspection should include external visual inspection with shell

UTMs, and an examination of the tank bottom by magnetic flux leakage (MFL or MFE) technology.

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

Andrew Swenck, PE

Structural Engineer

API 653 Inspector No. 56234

Enclosure – Tank 4236 – Shell Settlement Evaluation

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

Job Title: Robins AFB Date: 4/16/2015

Subject: Tank 4236 - Shell Settlement Evaluation By: Andrew Swenck

API 653 Appendix B

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

Diameter (D) = 62 (ft)

Number of equally spaced data points (ft)= 8

L = Arc length between measurement points (ft) = 24.35

Tank Height (H) = 52.0 (ft)

* Z U S

0 70.63 0.00 0.14 0.14 0.25

1 71.06 0.44 0.20 -0.24 -0.33

2 70.94 0.31 0.35 0.04 0.19

3 71.19 0.56 0.50 -0.06 -0.11

4 71.13 0.50 0.56 0.06 0.03

5 71.00 0.38 0.50 0.13 0.20

6 71.19 0.56 0.35 -0.21 -0.28

7 70.81 0.19 0.20 0.01 0.05

8 70.63 0.00 0.14 0.14 0.25

Maximum out-of -plane deflection = -0.33

* = 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 = 0.78 in

R^2 = (Syy - SSE) / Syy 0.6 not >=0.9 therefore cosine curve is invalid.

Evaluation by the Arc Length Method is required.