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Solicitation No. 140R6024Q0085 Amendment No. 0003

Description of Changes: The following changes are hereby incorporated into and made a part of this solicitation:

1. Answering of question received.

Receipt of Quotes: The hour and date for receipt of the quotes has not changed.

Third Party: If you have given a copy of the solicitation to someone else, please forward this amendment accordingly.

Q: I would like to formally request that sections D(3) and D(6) be relaxed to include continuous plate fins.

D. Finned Tubes:

1. Consisting of bi-metal tubes with the following properties:

a. Inner tube: 90/10 copper-nickel alloy in accordance with ASTM B111.

b. Outer tube:

1) Aluminum from which the integral fins are extruded and continuously mechanically bonded to the inner tube.

2) Aluminum purity of not less than 99.5 percent.

2. With extruded aluminum fins, allow a 3/8-inch gap at each end to prevent aluminum fins from contacting the copper alloy tube sheets.

3. Other fins, such as plate fins and serrated or cut fins, are not acceptable due to possible air side fouling.

4. Support fin tubes to prevent sagging, intermeshing of fins, and vibration at the generator natural frequency or its harmonics. Generator rotational speed is 163.6 revolutions per minute.

5. Finned tubes shall have straight ends. Finned tubes shall not have a belled end.

6. Finned-tube bundle shall be individually replaceable.

7. Water velocity in tubes shall not exceed 5 feet per second at maximum flow.

A: Please see the attached updated Performance Work Statement.

Bureau of Reclamation, Wyoming Area Office, Alcova Powerplant Generator Air Housing Cooler Supply Performance Work Statement

Scope

Supply a total of four new generator air housing coolers for Alcova Powerplant. Existing air housing coolers were originally manufactured by the Griscom-Russell Company. Each cooler weighs approximately 2,200 lb. Included is an original manufacturer inspection report excerpt containing cooler information available for all eight in-service coolers and one plant spare. The plant spare air housing cooler, an “as-shown” designation unit, will be made available for dimensional inspection or verification on-site by the contractor upon contract award.

The existing coolers are configured, as referred to on original documentation, as “as-shown” and “opposite-hand” units. Refer to original inspection report excerpts in Appendix A and photographs of various coolers in Appendix B for supply and discharge connection configurations associated with both cooler designations. As-built drawings included in Appendix C a representative of “As-Shown” units only.

Two of four coolers supplied are required to match the “As-Shown” configuration. Two of four coolers supplied are required to match the “Opposite-Hand” configuration.

All air housing cooler components must match the dimensions, materials, and component configuration shown in the attached drawing set included in Appendix C. Plate fins as a substitution for extruded fins shown on Appendix C drawings will be considered. Original equipment manufacturer (OEM) data specified a total of 50 tubes per cooler. Known OEM cooler data from original inspection documentation is included in Appendix A – Original Equipment Manufacturer Inspection Report Data. Photographs showing general air housing cooler condition and configuration are also included in Appendix B – Spare Air Housing Cooler Photographs.

Reference Standards

A. American Society of Mechanical Engineers (ASME)

1. ASME B31.1-22 Power Piping

2. ASME BPVC.II.A-23 Boiler and Pressure Vessel Code, Section II-

A: Ferrous Material Specifications (Beginning to SA-450)

3. ASME BPVC.VIII.1-23 Boiler and Pressure Vessel Code, Section VIII, Division 1: Rules for Construction of Pressure Vessels

4. ASME BPVC.IX-2023 Boiler and Pressure Vessel Code – Section IX, Qualification Standard for Welding, Brazing, and Fusing Procedures

B. ASTM International (ASTM)

1. ASTM A36/A36M-19 Carbon Structural Steel

2. ASTM A307-21 Carbon Steel Bolts, Studs, and Threaded

Rod 60,000 psi Tensile Strength

3. ASTM A563-21ae1 Carbon and Alloy Steel Nuts

4. ASTM A653/A653M-23 Steel Sheet, Zinc-Coated (Galvanized) or

Zinc-Iron Alloy Coated (Galvannealed) by the Hot-Dip Process

5. ASTM A924/A924M-22a General Requirements for Steel Sheet, Metallic-Coated by the Hot-Dip Process

6. ASTM B111/B111M-18a Copper and Copper-Alloy Seamless Condenser Tubes and Ferrule Stock

7. ASTM B171/171M-18 Copper-Alloy Plate and Sheet for Pressure Vessels, Condensers, and Heat Exchangers

System Description

A. Furnish and test air coolers of a modern design to replace the existing air coolers supplied with the Alcova generators.

B. Field verify dimensions and details from existing equipment at the jobsite, as required to design and furnish the air coolers. As-built air housing cooler drawings purchased by Reclamation via spare air housing cooler refurbishment contract are included in Appendix C for use by the Contractor. The Contractor is strongly urged to verify the information within these drawings by inspecting the spare air housing cooler on-site.

C. Existing System Description:

1. Alcova Unit 1 & Unit 2 Generators have 4 finned tube air-to-water air coolers each, mounted horizontally, spaced diametrically opposite on the periphery of the generator. The following are the approximate dimensions:

a. Approximate length, width and height of existing coolers is 129-inches by

29-inches by 14-inches.

b. Cooler Configuration:

1) As-Shown: Two coolers per generator

2) Opposite-Hand: Two coolers per generator

c. Air coolers are shown on As-Built Drawings listed in Appendix C. The full drawing set, purchased by Reclamation as part of a recent air cooler refurbishment contract, is also attached to this document. As-built drawings represent an “As-Shown” cooler configuration.

2. Cooling water for the air coolers is sourced from the scroll case and discharged to the tailrace.

3. The environmental air of the generator is passed through the air coolers and is then recirculated. Air is circulated through the air coolers by blades attached to the generator rotor.

4. Air temperature is controlled by the rate of raw water flow through the air coolers.

This is controlled by throttling the valves on the discharge side of the coolers.

Exit air temperature is not constantly monitored. Temperature switches for the purpose of generator protection are in place to alarm due to high discharge air temperature at each individual air cooler.

Design Requirements

A. Design, build, and certify air coolers to ASME BPVC Section VIII Division 1, and stamp with ASME Code "U" stamp.

B. Design coolers to allow thermal expansion and contraction.

C. Headers:

1. Boxed-type construction and of a floating head design to accommodate thermal expansion of tubes.

a. Match vents to existing vent connections.

b. Provide drains with brass plugs.

2. A36/SA-36 carbon steel per ASME BPVC.II Part A or ASTM A36.

a. Epoxy coated.

3. Constructed with removable covers to permit access to tubes for cleaning and inspection purposes without disturbing the water pipe connections.

4. Water inlet and outlet connections and locations shall match as-built drawings.

5. Minimum thickness for pass partition plates: Match 7/16-inch thickness shown on as-built drawings.

D. Finned Tubes:

1. Consisting of bi-metal tubes with the following properties:

a. Inner tube: 90/10 copper-nickel alloy in accordance with ASTM B111.

b. Outer tube:

1) Aluminum from which the integral fins are extruded and continuously mechanically bonded to the inner tube.

2) Aluminum purity of not less than 99.5 percent.

2. With extruded aluminum fins, allow a 3/8-inch gap at each end to prevent aluminum fins from contacting the copper alloy tube sheets.

3. Plate fins will be considered as a substitution for extruded fins.

4. Serrated or cut fins are not acceptable due to possible air side fouling.

5. Support fin tubes to prevent sagging, intermeshing of fins, and vibration at the generator natural frequency or its harmonics. Generator rotational speed is 163.6 revolutions per minute.

6. Finned tubes shall have straight ends. Finned tubes shall not have a belled end.

7. With extruded aluminum fins, the finned-tubes shall be individually replaceable.

8. Water velocity in tubes shall not exceed 5 feet per second at maximum flow.

E. Tube Sheets: 90/10 copper-nickel alloy in accordance with ASTM B171.

F. Frames: Heavy gauge galvanized steel in accordance with ASTM A924 and A653.

G. Hardware:

1. Carbon steel machine bolts in accordance with ASTM A307, Grade B.

2. Hex nuts in accordance with ASTM A563.

H. Coatings: Manufacturer’s standard coating system.

I. Performance Requirements:

1. Generator air coolers shall maintain temperature of the air inside the generator air housing between 35 and 40 degrees C under the following conditions:

a. Generator delivering 100-percent rated output of 18,950 kVA and a power factor of 0.95.

b. Maximum cooling water supply temperature: 25 degrees C.

c. Cooling water flow rate: 360 gpm total for the air housing cooler system.

d. Design pressure: 100 psi.

2. Air coolers shall be:

a. Rigid, self-contained, and designed for handling as a complete assembly.

b. Heavy-duty, industrial type suitable for continuous or cyclic duty operation.

c. Identical and interchangeable.

d. Free draining.

Delivery

Air housing cooler transportation to Alcova Powerplant will be the responsibility of the contractor. Plant staff will be available to load and off-load new coolers from an open trailer or truck bed with an overhead crane. If the vendor desires to transport the coolers in an enclosed trailer or van, the contractor will then be responsible for loading and off-loading. Pickup and delivery must be between the hours of 7:30 AM and 4:00 PM scheduled two weeks in advance.

Alcova Powerplant is located approximately 30 miles southwest of Casper, Wyoming on State Highway 220 in Alcova, WY at the following address:

US Bureau of Reclamation 22122 S. Kortes Rd Alcova, WY 82620

Please include freight costs as a proposal/bid line item separate from cooler retubing and refurbishment services.

Testing and Acceptance

The contractor will pressure test all four air housing coolers following delivery to Alcova Powerplant at a pressure of 150 psi for two hours to confirm that the refurbished cooler is free from leaks. If any leaks are found, repairs will be made at the expense of the contractor. The contractor shall be responsible for making arrangements for on-site pressure testing at least two weeks prior to delivery.

A. Government may witness field testing of the air coolers.

B. Notify COR in writing 14 days prior to delivery and testing.

C. Contractor Field Quality Testing per ASME B31.1:

1. Check each air cooler for leaks after on-site arrival.

2. Furnish equipment to perform the hydrostatic pressure tests.

3. Calibrate equipment immediately before testing.

4. Hydrostatic test to pressure of 1.5 times the design pressure for a 2-hour period with no leakage or reduction in pressure.

5. Hydrostatic tests performed by a qualified technician.

6. Submit a certified hydrostatic test report for each air cooler.

D. If leaks are found, repair and retest to the satisfaction of the COR.

Period of Performance

The spare air housing cooler will be available for dimensional inspection at Alcova Powerplant upon contract award. All contract work must be completed with four new air housing coolers delivered to Alcova Power Plant no later than June 27, 2025.

Prospective bidders are encouraged to inspect the air housing cooler prior to proposal submission. Please contact COR Byron Pindell at 307-261-5630 with technical questions or to arrange for a pre-bid site visit.

Drawings

The Alcova air housing cooler drawing set in Performance Work Statement Appendix C – As- Built Air Housing Cooler Drawing Set is included for information only and represent an “As- Shown” cooler configuration. All existing drawings were contractor-supplied as a deliverable via spare cooler refurbishment contract completed in fiscal year 2023. Dimensions found within the set should be considered as-builts applicable for the spare air housing cooler only. Upon supply contract award, a full set of AutoCAD (.dwg) format drawings will be furnished to the contractor.

In the scope of the present air housing cooler supply performance work statement, the contractor is expected to verify all cooler dimensions and update supplied AutoCAD-format drawings as needed to reflect dimensions or modifications as-supplied. The contractor shall supply drawings for both “As-Shown” and “Opposite-Hand” cooler configuration types. Upon delivery of new coolers, submit electronic copies of a complete CAD generated schematic showing all necessary dimensions, components, and modifications to coolers.

Submittals

A. RSN 22 11 85-1, Approval Data:

1. Commercial product data.

2. Design calculations and dimensioned drawings, stamped by a Professional

Engineer experienced in design of air coolers. Include:

a. Heat removal capacity calculation.

b. Hot and cool side temperatures at rated flow and design parameters.

c. Overall plan and sectional view drawings.

d. Parts list and material composition, including material, size, and other pertinent information.

e. Fastener tightening torques for headers, cover plates, and flanges.

f. Overall weights for each cooler.

g. Direction of water flow.

h. Pressure drop at rated flow.

i. Applicable design codes.

j. Mounting and connection details to existing piping.

k. Field verified dimensions, quantities, and connection details.

B. RSN 22 11 85-2, Approval Drawings

1. Fabrication drawings

2. As-Built drawings

C. RSN 22 11 85-3, Factory Test Plan and Schedule:

1. Detailed description of factory hydrostatic test method.

2. Estimated factory test dates and expected duration of tests performed.

D. RSN 22 11 85-4, Factory Test Reports:

1. Submit test reports after successful completion of factory tests.

E. RSN 22 11 85-5, Field Quality Test Plan and Schedule:

1. Detailed description of field hydrostatic test method.

2. Estimated field test dates and expected duration of tests performed.

F. RSN 22 11 85-6, Field Quality Test Reports:

1. Submit test reports after successful completion of field tests.

Appendix A - Original Equipment Manufacturer Inspection Report Data:

Representative “As-Shown” Unit Original Inspection Sheet.

Representative “Opposite-Hand” Unit Original Inspection Sheet.

Appendix B – Spare Air Housing Cooler Photographs:

Photo 1 – Spare “As-Shown” configuration cooler.

Photo 2 – Spare “As-Shown” configuration cooler.

Photo 3 – Spare “As-Shown” configuration cooler.

Photo 4 – Spare “As-Shown” configuration cooler.

Photo 5 – Spare “As-Shown” configuration cooler.

Photo 6 – Spare “As-Shown” configuration cooler.

Photo 7 – Spare “As-Shown” configuration cooler.

Photo 8 – Spare “As-Shown” configuration cooler.

Photo 9 – In-Service “Opposite-Hand” configuration cooler.

Appendix C – As-Built Air Housing Cooler Drawing Set:

Drawing List:

- 10398-00-DWG-01 (Cooler Assy)

- 10398-00-DWG-02 (Cooler, Finned Tubes, 4-Pass)

- 10398-01-DWG-01 (Frame Weldment)

- 10398-02-DWG-01 (Tube Sheet, Floating)

- 10398-03-DWG-01 (Cover & Water Box, Floating)

- 10398-04-DWG-01 (Tube Sheet, Stationary)

- 10398-05-DWG-01 Sheet 1 of 2 (Water Box, Stationary)

- 10398-05-DWG-01 Sheet 2 of 2 (Water Box, Stationary)

- 10398-06-DWG-01 (Cover, Stationary)

- 10398-07-DWG-01 (Panel, Side)

- 10398-08-DWG-01 (Bar, Stiffener, Long)

- 10398-09-DWG-01 (Angle, Frame)

- 10398-10-DWG-01 (Bar, Frame, Floating End, LG)

- 10398-11-DWG-01 (Bar, Frame, Fltg/Sta End, SHT)

- 10398-12-DWG-01 (Bracket, Lifting, Floating End)

- 10398-13-DWG-01 (Pin, Guide, Floating End)

- 10398-14-DWG-01 (Bar, Frame, Stationary End, LG)

- 10398-15-DWG-01 (Bar, Frame Spacer, Stationary End)

- 10398-16-DWG-01 (Bracket, Lifting, Stationary End)

- 10398-17-DWG-01 (Support, Tube)

- 10398-18-DWG-01 (Tube, With Collar)

- 10398-19-DWG-01 (Gasket, Stationary Spacer)

- 10398-20-DWG-01 (Gasket, Floating End)

- 10398-21-DWG-01 (Gasket, Water Box, Stationary)

- 10398-22-DWG-01 (Gasket, Cover, Stationary)