33_16_15_-_Thermal_Energy_Storage_Tank_Specification,_Amendment_4.pdf

HEAT RECOVERY SYSTEM – BUILDING 4607/4600 COMPLEX FAC-M5066

THERMAL ENERGY STORAGE TANK SPECIFICATION (AMENDMENT 4) 33 16 15 - 1

SECTION 33 16 15 - THERMAL ENERGY STORAGE TANK SPECIFICATION

PART 1 – GENERAL

1.1. SCOPE OF WORK

A. The work to be performed under these specifications includes furnishing all labor, materials, tools and equipment necessary to design, fabricate, construct, inspect and test a welded steel thermal energy storage (TES) tank, including the foundation, insulation and accessories as shown on the drawings and specified herein.

B. The work shall also include all labor, materials and equipment necessary to clean and paint the thermal energy storage tank as specified herein.

C. The work shall also include all labor, materials and equipment necessary to construct the site improvements required for the tank and foundation as shown on the drawings and specified herein.

D. The tank shall be a vertical, cylindrical, flat bottom type of all-welded steel construction.

E. Provide a complete hot water Thermal Energy Storage system as shown and as specified herein to meet applicable codes and site requirements, including but not limited to:

1. Foundation design.

2. Foundation.

3. Excavation, Backfilling, Compaction.

4. Foundation Anchor Bolt System Design.

5. Foundation Anchor Bolt System.

6. Storage Tank Design.

7. Storage Tank, including manways, openings and nozzles.

8. Storage Tank Instrumentation Wells and Penetrations

9. Insulation and painting.

10. Internal Distribution System Design

11. Internal Distribution System.

12. System Performance Testing.

13. System Commissioning.

F. The TES System is designed to store heating hot water in an above ground fully welded steel tank, which is charged with hot water during non-peak periods to satisfy a portion of the space heating requirements for the following peak load period. The system will utilize extremely low velocity lateral distribution and thermal stratification to maintain the temperature differential between the water in the top and bottom of the tank, while minimizing the "thermocline" or mixed region of hot supply and warm return water within the tank.

G. The TES System includes: Hot water storage tank (welded steel reservoir), soils evaluation and soils engineering, foundation and foundation design, interior and exterior painting and coating, lockable exterior ladder with safety cage and safety climbing device, reservoir distribution

THERMAL ENERGY STORAGE TANK SPECIFICATION (AMENDMENT 4) 33 16 15 - 2

thermal diffuser system, insulation, cladding system, tank and instrumentation appurtenances, testing, and commissioning.

H. The TES System shall be constructed and tested on the site in the designated location, and shall be complete in every way, conforming to the plans and specifications, and as detailed in the final design generated by the TES tank manufacturer and as submitted to the Government for review and comment. The TES System shall be capable of meeting or exceeding the useful water volume, the interior and exterior dimensions, the thermal capacity and performance called for in this document package.

I. Upon final installation of the tank, but prior to filling the tank, measurements shall be made inside the tank. Useful water volume less than that described by the document package shall be back charged to the manufacturer at the rate of $2.25 per gallon shortfall. Volumetric or dimensional overages shall not be compensated for, as it is assumed that sizes larger than that described in the document package may be necessary for certain manufacturers to meet the required ton-hour storage capacity.

J. The TES tank manufacturer shall warrant the thermal performance of the TES System as a whole as described within these specifications, and construction documents.

K. Note that this is intended to be a performance criteria type of specification. Any conflict with the drawings shall be brought to the attention of the COR for resolution.

L. Chemical treatment required for testing or for final system operation shall be furnished by the Government.

M. The dimensions indicated in the document package are minimums, but the shell diameter and overall height may not be exceeded by any significant amount (over 2' in any direction) without special evaluation and permission from the COR. If additional water volume is required by the specific TES tank manufacturer to meet the performance criteria with no negative tolerance for instrumentation, the COR shall be notified at the time of bid.

1.2. PRE-QUALIFICATION OF CONTRACTOR

A. The Contractor must have a minimum of five years of experience in the turnkey design and supply of operating TES Tank Systems, including a minimum of ten systems greater than or equal to 10,000 ton-hours of capacity that have met or exceeded their rated ton-hour storage capacity, as proven by actual field performance tests of installed systems, not merely calculated performance. The system and internals provided shall be of the Contractor’s own design and shall utilize principles and details proven operationally successful by field installations.

B. Upon request the Contractor shall provide reference (with customer contacts) for a similar, thermally-stratified, water storage installations currently in operation, exceeding 10,000 ton-hours of capacity, and utilizing modular internals of the Contractor’s own design that meet the requirements of Section 2.2.

C. Upon request the Contractor shall provide a minimum of three successful performance test results for stratified water storage installations currently in operation, each exceeding 10,000 ton-hours of capacity, and each utilizing modular internals that meet the requirements of Paragraph 2.2.C.

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D. At the time of bid, the Contractor shall provide a minimum of one reference (with customer contacts) for similar, thermally-stratified, hot water storage installations currently in operation for a minimum of six months.

1.3. REFERENCES

A. The materials, design, fabrication, erection and inspection of the welded steel thermal energy storage tank and foundation, shall conform to the latest editions of the following Standards, Codes, and Guides:

1. American Concrete Institute (ACI):

a. ACI 301 - Specification for Structural Concrete;

b. ACI 318 - Building Code Requirements for Structural Concrete.

2. American Society of Heating, Refrigeration, and Air Conditioning Engineers

(ASHRAE):

a. ASHRAE 2017 HVAC Fundamentals Handbook

b. ASHRAE 2016 HVAC Systems and Equipment, Chapter 50, Thermal Storage;

c. ASHRAE Design Guide for Cool Thermal Storage;

d. ASHRAE Standard 150, Method for Testing the Performance of Cool Storage

Systems.

3. American Society of Mechanical Engineers (ASME)

a. ASME B31.1- Code for Pressure Piping - Power Piping.

4. American Water Works Association (AWWA):

a. AWWA D100 Welded Steel Tanks for Water Storage;

b. AWWA D102 Painting Steel Water Storage Tanks.

5. Air-conditioning & Refrigeration Institute (ARI):

a. Guideline T - Specifying the Thermal Performance of Cool Storage Equipment;

b. ARI Standard 900, Thermal Storage Equipment Used for Cooling.

6. National Fire Protection Association (NFPA):

a. NFPA 780 – Standard for the Installation of Lightning Protection Systems.

7. Steel Structures Painting Manual and SSPC Standards, Volumes 1 and 2.

8. American Petroleum Institute (API)

a. API 650

THERMAL ENERGY STORAGE TANK SPECIFICATION (AMENDMENT 4) 33 16 15 - 4

1.4. GEOTECHNICAL INVESTIGATION

A. The Government shall provide a soils investigation report furnished by a qualified Geotechnical Engineer. Refer to Appendix A of this specification.

1.5. SUBMITTALS

A. The following Approval Drawings shall be stamped and certified by a Registered Professional Engineer licensed in the State of Alabama and submitted by the Contractor:

1. TES tank manufacturer shall prepare and submit a complete technical submittal including calculations and documentation on the tank, foundation, diffuser design and thermal performance of the reservoir/ diffuser systems as a part of the bidder’s proposal at the time of submission of the bid.

2. The technical proposal shall also include the following information as a minimum: Plan and profile views of the TES tank showing the minimum operating level, the operating level when the tank is full of 100°F water, the warm operating level when the tank is full of 140°F water, the warm operating level when the tank is full of 160°F water, the overflow level, the upper and lower diffuser opening heights, orientations and levels within the tank, a plan and profile view of the proposed diffuser systems used in the tank and a statement that the system is capable of operating in both the charge and discharge modes at all levels between the low level alarm and the overflow level, a range of one foot.

3. Tank orientation and elevation views.

4. Tank penetrations and points of interface with other contractors.

5. Tank design calculations including, but not limited to:

a. Tank sizing;

b. Internal flow distributor sizing calculations;

c. Pressure drop calculations;

d. Heat loss calculations.

e. Steel shell thickness calculations for the 48’ water height at overflow level and specific gravity required

6. Foundation calculations and drawings for the 48’ water height at overflow level and specific gravity required.

B. Product data shall be submitted for the following:

1. Coating data sheets and color sample.

2. Insulation details, data sheets and color sample.

3. Manhole hinge doors.

4. Tank roof hatches.

5. OSHA approved external ladder.

6. Concrete Mix Design.

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C. Welding

1. Welder’s certifications in accordance with AWWA D100 or API 650 (upon request).

2. Qualifications/Certifications of welding Supervisor/Inspector (upon request).

3. Tank weld map.

4. X-ray film and reports.

5. Vacuum box test reports.

D. Test Reports

1. Hydrostatic Test Report.

2. Performance Test Report.

3. Concrete Field Quality-Control Test Reports.

E. Shop Drawing

F. Operation and Maintenance Manuals

1. The Contractor shall provide 4 copies of the Operation and Maintenance Manual delivered within 30 days after substantial completion of field construction.

2. As a minimum, the manual shall include the following:

a. Thermodynamic description of each operating mode;

b. Safety precautions and instructions;

c. Detailed performance test procedure;

d. Recommended spare parts list;

e. Recommended maintenance practices and schedules for the tank foundation, structure, appurtenances, insulation, internal distribution systems, and special systems as may be supplied by the Contractor;

f. Local contact for the Contractor and for other manufacturers and suppliers of major components, as appropriate.

G. Written warranty as specified in 1.6.

1.6. WARRANTY

A. Contractor shall guarantee the thermal performance criteria of the TES System as specified in Section 2.3.

B. Contractor shall provide a one year warranty for materials and workmanship of the TES System.

C. All guarantees obtained by Contractor from manufacturers or installers of paint, equipment or accessories not manufactured by Contractor shall be obtained for the benefit of the Owner.

PART 2 - PRODUCTS

2.1. GENERAL

A. This specification describes a Thermal Energy Storage (TES) System designed, manufactured, and installed for use in meeting heating loads. The storage system will employ the principle of thermal stratification for storing hot and warm water in a single storage vessel.

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B. Contractor shall provide a TES system complete with all internal flow distributors as described herein to store thermally stratified water. Contractor shall guarantee the thermal performance of the hot water storage system.

C. The TES system will be integrated with a hot water supply system. The TES system will store hot water recovered during “off-peak” periods to meet “on-peak” thermal loads.

D. The storage tank shall be an above-ground, vertical, cylindrical, flat bottom tank of all-welded steel construction. The tank shall have a column-supported, fixed roof.

2.2. DESIGN CRITERIA

A. The tank shall be designed, constructed and tested in accordance with the latest edition of AWWA D100 or API 650.

1. Wind load: 90 mph.

2. Seismic design: per AWWA D100, Section 13 or API 650 Annex E.

3. Amount of freeboard to be provided for a seismic sloshing wave: Contractor to calculate in accordance with tank design guidelines.

4. AWWA D100 Section 14 or API 650 VPM (Variable Point Method) may be employed at the Contractor’s discretion.

5. Roof live load: minimum 40 psf.

6. Corrosion Allowance: None.

7. Maximum operating liquid level (invert of overflow) height: 48’00”.

8. Minimum operating liquid level height: 47’00”.

9. Minimum internal diameter shall be 40’.

10. Fluid specific gravity design criteria: 0.98 for water with corrosion inhibitor treatment.

11. Design Metal Temperature: In accordance with Code.

12. Tank shall have grounding (lugs).

13. Maximum intended operating temperature: 160°F.

14. Average low 1-day mean daily temperatures: In accordance with ASHRAE for

Huntsville, Alabama.

B. The bottom and roof plates shall be assembled using lap joints, welded continuously from the top side only. Shell plates to be 100% full fusion butt-welded joints.

C. Seismic Design

1. The TES tank, foundation system and all connections shall be designed per AWWA requirements for this seismic zone, and per the requirements of the manufacturer’s soils engineering and Geotechnical Report, whichever are more stringent.

D. Contractor shall provide all necessary internal flow distributors required to meet the thermal performance specified in Section 2.3.of this specification.

1. The internals shall be fully designed, fabricated and installed by Contractor.

2. The design shall be based upon proven flow distribution calculations to maintain and minimize the operating thermocline between the hot and cold water.

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3. The diffuser shall be inherently robust in order to minimize damage from infrequent, unanticipated waterhammer events that could be initiated elsewhere in the hydraulic system apart from the TES Storage Tank.

4. Components of the diffuser shall be supported by the tank structural members without the use of pipe hangers.

5. The distributors shall make maximum practical use of corrosion resistant, modular components sized to pass through the shell and roof manholes for easy removal and installation.

6. The individual modular diffuser components shall be capable of simple hand tool disassembly and re-assembly to facilitate inspection and painting of the tank bottom and roof support column(s). Such disassembly shall be accomplished without any cutting, sawing, burning, welding or gluing.

7. Adjacent components shall be of an interlocking, self-aligning design.

8. The modular, corrosion resistant diffuser design shall be based on heat type thermal storage installations.

E. All internal piping, including internal flow distributor and overflow, shall be schedule 40 welded carbon steel.

F. The insulation system shall meet or exceed the system performance requirements for heat loss as specified in Section 2.3 of this specification.

1. External insulation shall be provided as necessary to meet the thermal heat loss criteria.

Assume an average soils temperature of 50°F when calculating heat gains. Provide structural and cosmetic protection for this insulation during the welding process.

2. Drawings indicating details of insulation system and heat loss calculations shall be submitted to NASA for review prior to construction.

G. The insulation system shall be designed to withstand a 90 mph wind loading.

H. The shell and roof insulation system shall consist of the following:

1. Rigid insulation board, of polyurethane or polyisocyanurate. The board shall have a density of 2 PCF and an aged thermal conductivity value no more than 0.16 BTU-in/hr-ft2-ºF (R=6.25/inch).

2. The insulating boards shall be installed as single or multiple layers. The edges of the boards shall be tightly butted against each other. The joints of adjacent layers shall be offset a minimum of 6 in. both vertically and horizontally, during installation.

3. The outermost layer of the insulation board shall be bonded (laminated) to an aluminum jacket, of 0.024 in. minimum thickness, to provide weather and mechanical protection.

4. The metal jacket on both the shell and roof shall have a vertical standing closure seam.

All seams shall be sealed mechanically (by machine) at all accessible locations and hand sealing shall be minimized.

5. Any lapped seams shall be installed in the down weather position to allow water runoff.

6. Circumferential joints in the roof system shall consider expansion joints and a down weather lap position. The roof panels can be placed in a radial pattern or a “Chevron” pattern as required to best address the tank diameter.

7. The attachment system for the insulation panels shall be a concealed fastener system such as tensioned cables and/or pencil rods.

THERMAL ENERGY STORAGE TANK SPECIFICATION (AMENDMENT 4) 33 16 15 - 8

8. The exposed insulation jacket shall have an embossed or textured finish. The jacket will be factory coated with a polyester resin. The color shall be selected by the owner during the submittal review process.

9. A reinforced corner flashing metal shall be installed at the transition of the roof to shell jackets. This flashing section shall be a rolled section (as opposed to segmental strips).

Care shall be taken to minimize penetrations through this corner flashing. Corner flashing shall be adequately sealed and insulated.

10. The insulation system shall include removable insulated covers for:

a. Manholes (shell and roof)

b. Anchor bolt chairs (if required).

11. Tank Contractor’s supplied insulation system shall not include insulation of process piping, nozzles, valves and interconnecting piping past the first tank piping flange. These items will be the responsibility of the Mechanical Contractor.

12. Penetrations through the metal jacket shall be sealed with a non-hardening flexible butyl sealant (or approved equivalent) and penetrations on the roof shall be sealed using a “pitch pot” detail.

13. The perimeter area where the tank shell meets the foundation shall be adequately sealed and insulated. This shall be accomplished by securing insulation and flashing to the tank shall jacket and to a rolled angle located outboard of the tank bottom secured to the concrete foundation with concrete anchors.

14. An external bottom insulation system shall be provided as necessary to meet the heat loss limits of Paragraph 2.3.D. of this specification. The system shall be suitably protected from damage during installation and welding of the tank bottom.

15. The tank foundation shall be designed by the TES tank manufacturer to fit the tank footprint as shown on the site construction drawings. The foundation diameter may exceed the tank diameter by up to 10' as may be required by the local soils condition and foundation design. The foundation and seismic anchors (if required) shall be designed to meet the requirements of the American Water Work Association (AWWA), D100 or API 650, and all other applicable codes, standards and references, whichever are most stringent.

16. The TES tank manufacturer shall design the tank to foundation system anchorage (if required) accordingly and verify that the foundation system meets the requirements of the tank bottom and shell design. Slope the top outer edge of the foundation wall to drain away from the tank.

17. Any additional information, over and above that provided to the contractor at the time of bid that may be required to develop and implement a foundation design is the responsibility of the proposing TES tank manufacturer.

18. The minimum floor plate thickness shall be 1/4".

19. The minimum shell and roof plate thickness shall be 3/16" or as required to comply with

AWWA or API 650 requirements, whichever is thicker.

20. Materials:

a. Plate: Steel plates shall conform to the requirements of ASTM A36 or ASTM A992.

b. Rolled Structural Shapes: Rolled structural shapes shall conform to ASTM A36 or ASTM A992.

2.3. SYSTEM PERFORMANCE

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A. STORAGE: The TES distribution system shall be capable of storing and delivering a minimum of approximately 91,000,000 BTUs of thermal energy as heating hot water for a 47’ maximum water level. The thermal energy storage is based on approximately 25 degrees Fahrenheit Temperature Delta. The assumed volumetric size for the 40’ Diameter x 50’ Tall structure at a fill height of 47’ is 440,000 gallons.

B. RECHARGE: Recharging of the TES system (by owner) will occur primarily during the offpeak period(s). Cold water shall be removed from the bottom of the storage at a variable rate up to a maximum rate of 480 GPM, heated to an operating temperature of 118°F with a potential maximum of 160°F, and returned to the top of the tank. Recharging shall continue until full heating storage capacity is attained.

C. DISCHARGE: Hot water supply shall be removed from the TES system during discharge at a variable rate up to a maximum rate of 1,170 GPM to meet a peak heating requirement. Cold water return at an operating temperature of 93°F with a potential maximum of 125°F shall be returned to the bottom of the tank at an equal mass flow rate.

D. HEAT LOSS: The TES system shall limit the ambient heat loss to less than 2 % of the rated thermal storage capacity in a 24 hour period with 160°F stored hot water and the minimum ambient dry bulb temperature for the 99.6% heating design conditions for this locale from the ASHRAE 2013 Fundamentals Handbook.

E. HEAD LOSS: The total hydraulic head loss from the tank inlet flange to the tank outlet flange at the maximum design flow rate of 1,170 GPM will be a maximum of 3.0 psid.

F. PERFORMANCE TEST: A Performance test, among other things, shall form the final basis for acceptance of the thermal energy storage system (TES). The test will verify the ability of the TES System to meet the performance requirements for recharge and discharge. The test will be supervised by NASA, arranged and provided by the TES supplier, mechanical and controls contractors, and witnessed by the Engineer of Record.

G. INTERNAL USEFUL WATER VOLUME TEST: Measurements shall be taken to determine compliance with all dimensional information provided as a part of this document package.

2.4. APPURTENANCES

A. Refer to Drawings. Tank shall have as a minimum the following fittings and accessories:

1. One (1) 30 inch diameter shell access manhole with davit (or hinged door).

2. One (1) 24 inch diameter shell access manhole with davit (or hinged door).

3. Two (2) 36 inch square rain-proof roof access hatches (one located near the center of the roof).

a. The tank roof hatches shall have a curbed, upward oriented man sized opening, 36" square, minimum. The curb shall extend at least four inches above the tank. The hatch cover lip shall be hinged, insulated and gasketed, with provisions made for locking, with a minimum of two locks for the hatch. The hatch cover lip should extend for a distance of two inches down on the outside of the curb.

4. One (1) 8 inch diameter warm water inlet/outlet nozzle.

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5. One (1) 8 inch diameter cold water inlet/outlet nozzle.

6. One (1) overflow nozzle with an internal overflow pipe and an external seize-resistant, anti-thermosiphon device within three (3) feet of grade. Overflow to be sized for the maximum flow entering the tank through the fill nozzle at the rate of 400 GPM.

7. One (1) 6 inch diameter center column clean out nozzle with blind flange.

8. One (1) 1/4 inch (one-quarter inch) diameter center column air bleed hole at the top of the bottom piping.

a. If the lower diffuser design has multiple high points, each high point shall have a ¼ inch (one-quarter inch) diameter air bleed hole.

9. One (1) 1/4 inch (one-quarter inch) diameter center column drain hole, at the bottom of the top piping.

a. If the upper diffuser design has multiple low points that could trap water when the tank is drained, each low point shall have a 1/4 inch (one-quarter inch) diameter water drain hole.

10. One (1) roof vent designed/constructed to prevent entrance of birds or animals. Vent shall have the capacity to pass air so that at the maximum possible rate of water, either entering or leaving the tank, excessive pressure will not be developed. The overflow pipe shall not be considered a tank vent. Extend vent such that opening is 12" minimum above the roof.

11. One (1) 8 inch diameter roof mounted spare nozzle with blind flange.

12. Two (2) 8 inch diameter shell mounted flanged spare nozzles with blind flanges (3 feet above tank floor).

13. Twenty four (24) welded ½” NPT threadolets for thermowells equally-spaced in the shell alongside the roof access ladder.

14. Twenty six (26) Conduit attachments for thermal charge and level instrumentation.

15. One (1) straight external ladder with galvanized fall prevention device and safety cage and two (2) belts as required by OSHA and a walk-thru at the roof. Provide an OSHA approved roof mounted safety cage. Enclose a minimum of 800 square feet on the roof to access roof nozzles

a. There shall be a landing for the ladder at the 24’ level, prior to the ladder continuing on to the roof of the tank.

b. The ladder shall be connected to the tank with thermal breaks such that there shall be no ladder heating above 120°F.

16. Grounding lugs as specified in subparagraph 7.4.1.7.2 (3) of NFPA 780. The supply of the associated grounding cables and rods, and their installation, will be by other trades under this contract.

17. Thermal charge instrumentation will be provided by others. Contractor shall provide the required fittings and mounting brackets, see other paragraphs of this specification.

18. Level instrumentation with high and low level alarm capability will be provided by other trades under this Contract. The Contractor shall provide the required fittings and mounting brackets.

19. One (1) 2 inch diameter roof mounted flanged nozzle to be used for level instruments.

20. Provide connection points for water level sensors and tank temperature sensors as shown on the attached drawings or required by the specifications. Ensure that these elements are

THERMAL ENERGY STORAGE TANK SPECIFICATION (AMENDMENT 4) 33 16 15 - 11

located near the outside access ladder and within the roof mounted safety cage where they can be reached safely for service.

2.5. COATINGS & FINISHES

A. GENERAL

1. All tank painting shall be in accordance with:

a. AWWA D102,

b. the Steel Structures Painting Council Specification, SSPC-PA1,

c. approved paint manufacturer specifications, and

d. this specification.

2. Pre-construction primers may be utilized in the fabrication process to preserve the blast profile and cleanliness. In the field, weld seams and abraded areas shall be cleaned on a spot basis. The remaining sound primer shall be cleaned to remove dirt and other contaminants. After cleaning the specified coating shall be applied in its entirety in the field at the thicknesses specified.

3. No paint shall be applied when the temperature of the surface to be painted is below the minimum temperature specified by the paint manufacturer, or less than 5 degrees above the dew point temperature. Paint shall not be applied to wet or damp surfaces or when the relative humidity exceeds 85% unless allowed by manufacturer’s data sheets. Follow the paint manufacturer’s recommendations for the specific paint system used.

4. After erection and before painting, remove slag, weld metal splatter and sharp edges by chipping or grinding. All outside surfaces that have been welded, abraded or otherwise damaged, shall be blast cleaned per SSPC-SP 6. Inside damaged or uncoated surfaces shall be blast cleaned per SSPC-SP 10. Primer shall be applied in the field in accordance with the paint system requirements.

5. All areas blasted in the field shall be coated the same day before any rusting or corrosion occurs.

6. The dry film thickness values shown below are average values subject to variation in thickness based upon industry practice and manufacturers recommendation. The actual dry film thickness value measured may vary from these average values within the range established by the manufacturer.

7. Stainless Steel, aluminum, galvanized and non-metallic surfaces require no additional coatings. Erection damage to galvanized surfaces, if any, shall be touched up with “Galvanox” or equal.

8. All metal plates, supports, members and miscellaneous parts except bolts shall be factory coated in accordance with AWWA coating procedures.

B. Exterior Coating System

1. The exterior paint system shall conform to Inside Coating System No. 1 as defined in

AWWA D102.

a. The exposed exterior tank paint color shall be selected by the owner during the submittal review process.

b. The tank under bottom shall not be coated.

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c. If uninsulated (drain pipe, ladder, safety cage, conduit) - AWWA D102 ICS—1-S (color to match insulating jacket).

d. Tank and piping surface that is to be insulated – One primer coat (5 mil DFT) from

AWWA D102 ICS-1-W.

C. Interior Coating System

1. The Interior Paint System shall conform to Inside Coating System No.1 as defined in

AWWA D102.

a. The tank interior shall be left in a broom-clean condition after completion of painting.

PART 3 - EXECUTION

3.1. INSPECTION

A. Mill or shop inspection reports shall be supplied per AWWA Section 11 and shall be in accordance with Section 11 of AWWA D100 or API 650.

3.2. CONCRETE FOUNDATION

A. The foundation, as a minimum, shall be a reinforced concrete ringwall meeting the construction tolerances and design requirements of AWWA D100 or API 650 and ACI 318. The Contractor shall design the foundation to meet the recommendations of the attached owner supplied geotechnical report for a net allowable bearing value as indicated in the drawing set.

B. The foundation shall be designed for a 48’ water overflow level within the TES tank, and a fluid specific gravity of 1.08.

C. The foundation shall be sloped to prevent the accumulation of rainwater. For unanchored tanks, the shell shall be supported by an asphalt-impregnated fiberboard as specified in AWWA D100.

If anchorage is required, the tank shall be shimmed and grouted with a sand/cement mixture.

D. The vertical surfaces of the ringwall shall be formed (“neat” construction shall not be permitted). The top surface of the ringwall shall be level ± 1/8 in. in any 30 ft. circumference under the shell. The complete levelness on the circumference shall not vary by more than ± ¼

in. from an established plane.

E. Minimum acceptable concrete mix parameters are:

1. Concrete compressive strength, f’c: 4000 psi;

2. Slump: 3 in. ± 1 in.;

3. Air content: 3% to 6%;

4. Maximum aggregate size: 11/2 in.

5. Water-cement ratio of the concrete shall not exceed 0.53 for non air-entrained concrete.

6. In areas where air-entrainment is required for freeze-thaw protection, the maximum water to cement ratio shall be 0.46.

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F. A sand cushion shall be supplied under the tank. The sand shall pass a 3/4 in. sieve with less than 5% retention on a 3/8 in. sieve and less than 10% passing a #200 sieve. The sand shall be clean, free from clay balls and lumps of earth and shall be free of corrosive materials, such as salt and sulfur. The maximum chloride content shall be less than 0.03% (300 parts per million) and the maximum sulfate content shall be less than 0.10% (1000 PPM).

3.3. WELDING

A. All welders shall be qualified by ASME Section IX for the processes and positions utilized.

B. Contractor shall employ the services of a Certified Welding Inspector independent of the tank erection foreman’s jurisdiction.

C. Welding shall be inspected and tested by radiographic testing consistent with the requirements of Section 11 of AWWA D100 or API 650. Sectional segments will not be allowed. Additional inspection requirements detailed in Section 14 will be performed if the tank is designed to Section 14.

D. Tank shall be tested in accordance with AWWA D100 or API 650 specifications and as stated below.

1. Tank bottom shall be tested and examined by the Vacuum Box Test Method.

Reinforcing plates shall be tested prior to the shell test. Apply 5 (+1) psig air pressure using the telltale hole. While under pressure, a soap suds solution shall be applied to all attachment welds for detection of leaks.

2. Any leaks discovered by this test shall be corrected by the TES tank manufacturer.

3. Water required for testing shall be furnished once at the time of tank completion by

NASA without charge. All other fillings which may be required due to tank related problems will be at the TES tank manufacturer’s expense.

E. The edges or surfaces of the pieces to be joined by welding shall be prepared by flame cutting, plasma arc cutting, arc gouging, machining, shearing, grinding or chipping and shall be cleaned of detrimental oil, grease, scale and rust. The edges of the pieces may have a protective coating applied to them which need not be removed before they are welded unless specifically prohibited by the WPS.

F. Welding procedures and welding operators shall be qualified in accordance with ASME Section IX. All field welding may be done by the shielded metal arc welding process, the gas metal arc welding process, the flux core arc welding process, or the submerged arc welding process.

Shop welding may be done by the shielded metal arc process, the submerged arc welding process, the gas metal arc welding process, or the flux core metal arc welding process.

G. Plates and component members of the tank shall be assembled and welded following erection methods that minimize the amount of distortion due to weld shrinkage. The weld metal shall meet or exceed the minimum requirements for visual inspection in AWWA D100 Section 11.4 or API 650 and as set forth in the radiographic acceptance standards of AWWA D100 Section

11.6.10 or API 650. Surfaces to be welded shall be free from loose scale, slag, heavy rust, grease, paint and other foreign material.

THERMAL ENERGY STORAGE TANK SPECIFICATION (AMENDMENT 4) 33 16 15 - 14

3.4. TESTING & WATER TREATMENT

A. Hydrostatic Test

1. In accordance with AWWA D100, the Owner has opted to fill and test the tank after the completion and acceptance of the tank coating. Upon completion of an acceptable test, the test water will be retained for process use. Cleaning, flushing and water treatment are not the responsibility of Contractor.

2. Connection and supply of water will not be the responsibility of Contractor. The tank will be filled to the overflow level proportionally over a 48 hour period. Contractor shall supply an inspector for both days of the test. The hydrotest inspection shall be a visual leak inspection made from grade and existing ladders, stairways and platforms.

3. Do not make final piping connections to TES tank until 45 days after the final fill increment to the 40' water level to allow for tank settlement.

B. Performance Test

1. The final acceptance of the TES System will not be made until the thermal performance, system pressure drop, and internal and useful water volume measurement requirements have been met. It shall be the TES tank manufacturer’s responsibility to make such adjustments and modifications of the TES System diffusers and/or tank as may be necessary to attain the specified thermal, pressure drop and flow performance.

2. TES tank manufacturer shall be responsible for reimbursing NASA for any additional direct or indirect costs incurred by NASA due to a retesting process. The second and all remaining system tests shall be paid for by the TES tank manufacturer. This includes all NASA incurred expenses such as additional design team and commissioning team hours.

This includes system retests which may be required for all reasons other than direct NASA fault.

3. A test shall be the basis for acceptance of the TES System's thermal performance. The test shall verify the ability of the TES tank system to meet requirements of recharge and discharge (or recharge only, if the desired return water temperatures are not available).

This test shall take place at such time as all related systems including the TES tank, mechanical system, and electrical systems are complete and operational. NASA and NASA’s engineer shall supervise the test and evaluate the results.

4. A testing plan shall be developed jointly by the TES, mechanical and control system contractors and submitted for review and approval prior to scheduling the tests. The plan shall indicate the proposed testing instrumentation, planned methodology of obtaining a heating load to be served during the discharge cycle, or alternately performing a recharge test only if the required return water temperatures are not available, planned methodology of performing the tests, and criteria for determining whether the tested performance has been satisfactory (interpreting the requirements of these specifications).

5. Requirements:

a. The Owner shall conduct a performance test of the TES system to verify its ability to meet the performance requirements of Paragraph 2.3 of this specification. The test will take place within 30 days of substantial completion of the TES System, including connection to the heat exchanger water plant. Prior to the test, the Owner/Engineer will provide data confirming that the heat exchanger water charging and discharging system is operational. A minimum of three complete charge/complete discharge cycles will have occurred prior to scheduling the performance test.

THERMAL ENERGY STORAGE TANK SPECIFICATION (AMENDMENT 4) 33 16 15 - 15

b. If the design heating load at the appropriate temperatures is not available at the time of testing, the performance test shall be based solely on recharging the TES System.

c. Supply and operation of all mechanical equipment, controls and data recording devices shall be by the Owner or the Owner’s representative. Contractor shall provide a qualified engineer to monitor the test. Contractor shall review the test data and issue a written report to the owner.

d. The TES System shall have met the specified performance requirements if after the flow of one complete tank volume, the stored capacity is equal to or greater than the design value in Paragraph 2.3 of this specification (within the accuracy of the flow and temperature instrumentation).

e. Test Instrumentation

1) Instrumentation required for these tests shall be of industrial grade and accuracy (+/- 0.12°F, +/- 2.0% flow).

2) Use of the sitewide DDC system as the data logger is acceptable, providing that the instrumentation complies with all of the specifications.

6. Preparation:

a. The Owner will notify Contractor at least two (2) weeks prior to test date.

b. Prior to the test, at least the lowest eight (8) feet of the water in the storage tank will be heated to the design supply temperature and will be held for six (6) days to confirm that the soil and foundation have reached a steady state thermal condition.

c. After completing the initial charge/discharge testing and the six day holding period in Section 3.4, the TES system shall be brought to a fully discharged condition as expeditiously as possible (all water at approximately 93ºF, with no tank wall temperature sensors indicating temperatures lower than 88°F or greater than 98°F) to initiate the performance test.

d. The Owner will confirm that calibrated inlet or outlet flow meter, inlet/outlet temperature instrumentation and thermal charge instrumentation are operational.

7. Test Procedure:

a. Acceptance Test: The acceptance test shall be conducted to prove compliance in three (3) areas; recharge, discharge, and internal volume.

b. Recharge: Cold water shall be withdrawn from the bottom of storage at a maximum rate of up to 480 GPM. Cold water will be heated to 118°F (+0.50°F/- 1°F) and returned to distribution header at the top of the storage tank.

Discharge: Hot water shall be withdrawn from the top of storage at a maximum rate of up to 1170 GPM. Hot water will be cooled to 93°F (+0.50°F/-1°F) and returned to distribution header at the bottom of the storage tank.

c. Upon completion of the recharge cycle test, total integrated energy capacity delivered will be evaluated and used as the basis for recharge performance acceptance.

d. Internal system pressure drop: The pressure drop within the tank system, from flange to flange, including the pressure drop associated with the manual isolation valves, should not exceed 3 PSI at 1,170 GPM flow rate.

1) The pressure drop shall be measured across the two hot water lines entering the TES tank, on the tank side of the manual isolation valves, at

THERMAL ENERGY STORAGE TANK SPECIFICATION (AMENDMENT 4) 33 16 15 - 16

a design flow rate of 1,170 GPM. Readings shall be taken for the flow rate and differential pressure every 15 seconds for a 2 minute period, and this data shall be used to determine the passage or failure of the pressure drop test.

e. Monitoring

1) Flow and temperature values (into and out of the tank, and all the sensors measuring temperature inside the tank) shall be continuously integrated and recorded automatically at one minute intervals by the site DDC system, and manually at fifteen (15) minute intervals at all respective locations throughout the entire testing period. Heat delivered during each fifteen minute interval can be determined by:

a) Qn = Mn x(Mn (Th,n-Tc,n)) x F

b) Where:n = Specific 15 minute interval

c) Q = Heat delivered in BTU/hour

d) M = Flow Rate in gpm

e) Th = Hot supply water temperature (°F)

f) Tc = Cold return temperature (°F)

g) F = Conversion Factor = 122.7

2) Total integrated heat capacity delivered during discharge period is:

a) Q Total = Sum nf Q n

b) n = ni

c) Where: ni = the initial interval value

d) nf = the final interval value

f. NOT USED

g. If the TES System does not perform as specified, this Supplier shall be given the opportunity to repair, alter or modify the TES System within 30 days.

h. The performance test described in this document package shall be basis for determining the recharge and discharge capacities of the TES System.

i. The TES tank manufacturer shall warrant against any defects in workmanship and materials for a period of one (1) year from date of acceptance by NASA.

j. Recharge capacity shortfalls shall be backcharged at the rate of $250.00 per 10 MBH shortfall, in addition to the discharge capacity shortfall, should one exist.

k. Discharge capacity shortfalls shall be backcharged at the rate of $250.00 per 10 MBH shortfall, in addition to the recharge capacity shortfall, should one exist.

l. Flange to flange pressure drop overages shall be charged at the rate of $40,000 per foot of differential pressure in excess of the 3 PSID pressure drop requirement.

m. For the purpose of determining capacities, differential pressures, and the like for the use of determining the financial penalties to be imposed on the manufacturer, it shall be assumed that there is no negative tolerance on the instrumentation. This means that all instrumentation errors shall be calculated to be in the favor of

NASA.

n. This will have the effect of ensuring that NASA receives the capacity and performance desired and paid for, in that the manufacturer will not be able to rely upon instrument error to artificially increase the capacity of the Tank System.

THERMAL ENERGY STORAGE TANK SPECIFICATION (AMENDMENT 4) 33 16 15 - 17

3.5. COMMISSIONING SERVICES FOR PROJECT

A. Provide the services of respective manufacturer representatives furnishing equipment specified in this Section, to train NASA on the proper use of equipment and systems furnished, and to explain how this equipment, or system functions.

B. Provide installation, operation, parts lists, maintenance manuals and instruction in written form for each piece of equipment furnished herein, for the Operation and Maintenance Manuals.

END OF SECTION