Dean pump repair SOW.docx

STATEMENT OF WORK

REPAIR AND RECONDITION HIGH TEMPERATURE HOT WATER CIRCULATION PUMP

1. Summary of Work:

The contractor shall provide all labor, equipment, and materials to repair and recondition the Dean Brothers R-484 6x8-15 ½ end-suction centrifugal type pump used on the distribution system of the high temperature hot water heating plant. The Contractor shall recondition the pump using upgraded materials and precision-engineered components in accordance with this specification. This shall include a new high-performance mechanical seal, composite wear parts, and a one-piece shaft design. All work shall meet or exceed the original manufacturer’s performance criteria. Shipping costs back to Malmstrom AFB shall be included in the quoted price. Statement of Work Based on previously completed inspection of Dean Brothers R-484 Hot Water Circulation Pump on 13 March 2025.

2. Pump Information:

2.1. Manufacturer: Dean Brothers

2.2. Model: R-484

2.3. Size: 6x8-15 ½

2.4. Serial Number: 147006

3. WORK SCOPE:

3.1. Qualification:

3.1.1. All work shall be performed by a contractor with demonstrated experience in heavy industrial high-temperature centrifugal pump repair, rotating equipment rebuilds, and specifically the application of high-performance composite materials within rotating equipment

3.2. Repair Scope Justification:

3.2.1. Based on the inspection performed on 13 March 2025 of the Dean Brothers R-484 Hot Water Circulation Pump

3.3. Inspection:

3.3.1. Visual inspection of all components

3.3.2. Disassemble pump

3.3.3. Record run-outs

3.3.4. Record clearances

3.3.5. Disassemble rotor

3.3.6. Record clearances

3.3.7. Check case/cover split line

3.3.8. Sandblast cast components as needed

3.3.9. Clean components

3.4. Case:

3.4.1. Inspect machined fits for proper dimensions and for any defects

3.4.2. Machine fits if required to clean up surfaces and achieve acceptable TIR/Concentricity

3.4.3. Clean and de-burr all sharp edges

3.4.4. Prep for final assembly

3.5. Cover:

3.5.1. Inspect machined fits for proper dimensions and for any defects

3.5.2. Minor Weld Build-up of fits (weld pads) every 90 degrees on the outer diameters of the cover

3.5.3. Machine weld pads to achieve reduced clearances as required by reduced wear ring & bushing running clearances

3.5.4. Sleeve the seal chamber bore with a press fit 316L stainless steel sleeve, to repair corrosion damage

3.5.5. Machine the seal chamber bore to allow for the proper running clearance of the PPC Mechanical Seal with Plan 23 flush, and concentric installation of the throat bushing

3.5.6. The cover must be machined so the seal chamber bores are concentric to the outer diameters of the cover. In addition, the mounting surfaces/faces must be parallel and perpendicular to each other, and the seal chamber bore

3.5.7. Clean and de-burr all sharp edges

3.5.8. Prep for final assembly

3.6. Adapter – Cover to Bearing Frame:

3.6.1. Inspect machined fits for proper dimensions and for any defects

3.6.2. Minor Weld Repair/Build-up of fits (weld pads) if required

3.6.3. Machine fits if required to achieve minimum manufacturer recommended clearances

3.6.4. Clean and de-burr all sharp edges

3.6.5. Prep for final assembly

3.7. Case & Cover Wear Rings and Throat Bushing:

3.7.1. Composite Material Specification – CFPC-X/Y

3.7.1.1. All non-metallic wear parts, including the case wear ring, cover wear ring, and throat bushing, shall be manufactured from CFPC-X/Y, a carbon fiber reinforced polymer composite with a minimum 20% mass fraction of randomly oriented carbon fibers in the planar X-Y direction. The material shall exhibit low thermal expansion in the X-Y plane, high dimensional stability, and excellent resistance to wear, galling, and seizing. It shall be suitable for elevated temperature service in close-clearance pump components and capable of withstanding dry-run or boundary lubrication conditions without degradation

3.7.1.2. Acceptable materials include DuPont™ Vespel® CR-6100, Greene Tweed WR®600, or approved equal. Proposed substitutes must meet or exceed all specified performance characteristics and shall be submitted with supporting technical documentation. Approval of alternate materials is at the sole discretion of the Owner or Engineer

3.7.1.3. Composite wear parts shall be engineered by personnel with demonstrated expertise in high-temperature centrifugal pump repair and the application of carbon fiber reinforced composites. Dimensions shall not replicate OEM metallic components. Designs must be purpose-built for CFPC-X/Y materials, with proper consideration for thermal expansion, press fits, interference tolerances, and service conditions.

3.7.1.4. Use of off-the-shelf conversions, reverse-engineered metallic designs, or any component that fails to account for the specific behavior of CFPC-X/Y materials will be rejected

3.7.2. Manufacture new CFPC-X/Y case wear ring.

3.7.3. Manufacture new CFPC-X/Y cover wear ring.

3.7.4. Manufacture new CFPC-X/Y throat bushing.

3.7.5. Perform inspection of finished parts and work performed

3.8. Shaft:

3.8.1. Manufacture new shaft from 12% chromium stainless steel (Type 410 or equivalent), with mechanical properties suitable for high-temperature centrifugal pump service.

3.8.2. Eliminate the shaft sleeve. Shaft shall be a one-piece, fully machined component incorporating all functional surfaces.

3.8.3. All critical fits, tolerances, and surface finishes shall conform to industry standards, including ASME B4.1, ANSI/AGMA 6000, and ASTM A276, as applicable.

3.8.4. All machined surfaces shall be free of chatter, scoring, or tool marks that could affect seal or bearing performance

3.8.5. Inspect newly manufactured shaft TIR’s and all mechanical fits

3.8.6. Prep for final assembly

3.9. Impeller:

3.9.1. Inspect impeller prior to any work for damage, etc.

3.9.2. Tack weld or set screw all impeller wear rings in three places if required

3.9.3. Perform final inspection of impeller and work performed

3.9.4. Prep for final assembly

Shaft:

3.9.5. Inspect for TIR

3.9.6. Polish impeller fits

3.9.7. Clean threads

3.9.8. Prep for final assembly

3.10. Rotating Assembly:

3.10.1. Machine impeller installed on shaft as one rotating assembly

3.10.2. Skim cut impeller wear rings OD surfaces

3.10.3. Perform final finish OD’s to proper surface finish

3.10.4. Ensure proper TIR of impeller wear ring OD’s and sleeve OD/s to +/- 0.001”

3.10.5. Balance the rotating assembly in accordance with ISO 21940-11, achieving a minimum of Balance Quality Grade G2.5

3.10.6. Final balance shall be verified and documented prior to assembly

3.11. Bearing Housing:

3.11.1. Clean bearing housing

3.11.2. Inspect machined fits for proper dimensions and for any defects

3.11.3. Prep for final assembly

3.12. Pump Seal

3.12.1. Install PPC Mechanical Seals 682A-I-HB1T single cartridge mechanical seal with integrated pumping ring. The seal is based on API 682 design principles (Category II, Type A, Arrangement 1) but is not API 682 compliant

3.12.2. The seal shall include:

3.12.2.1. Thin cross-section rotary with integral pumping ring

3.12.2.2. Gland configured for flush, quench, and drain ports

3.12.2.3. Secondary containment by floating carbon bushing

3.12.2.4. Materials: 316 stainless steel metal components, FKM o-rings, silicon carbide vs. #10 metal-filled carbon seal faces

3.12.3. Seal shall be installed per the manufacturer recommendations

3.12.4. The seal is intended to operate with a Plan 23-style flush, utilizing a pumping ring for recirculation to a seal chamber cooler. This is not an API-compliant Plan 23 system

3.12.5. All piping, heat exchanger, and auxiliary components related to the flush system shall be provided by the customer as stated in Section 3.12

3.13. Seal Flush:

3.13.1. Verify all seal flush ports are correctly configured to support effective cooling and circulation for the Plan 23-style system

3.13.2. Plan 23 Seal Flush piping, heat exchanger and auxiliary components will be the customer’s responsibility and are not included in this scope of supply

3.14. Closed System Lubrication:

3.14.1. Install new ISOMAG magnetic bearing isolators

3.14.2. ISOMAG isolators are the basis of design. Alternate products must be magnetic, sealing-type bearing isolators with proven long-term service in centrifugal pump applications and must be submitted with performance data for review and approval prior to manufacture

3.14.2.1. Required modification of existing bearing covers that was previously performed

3.14.3. Reuse or replace Oil-Rite milled aluminum level gauge with dial thermometer and Viton seals

3.14.3.1. Required modification of existing bearing frame that was previously performed

3.15. Final Assembly:

3.15.1. Install new parts listed in the table below

3.15.2. Install case wear ring into pump case

3.15.3. Install cover wear ring into pump cover

3.15.4. Install stuffing box bushing into pump cover

3.15.5. Apply sealant to gland studs to prevent leakage of coolant from the cover’s cooling chamber

3.15.6. Orient stuffing box chamber vent in Top Vertical (12:00) position

3.15.7. Record final clearances

3.15.8. Record final run-outs

3.15.9. Install mechanical seal

3.15.10. Install coupling hub if provided

3.15.11. Apply proper torque to all fasteners

3.15.12. Perform final inspection of all installations and completed work

3.15.13. Air test the assembled unit for 30 minutes and record results

3.15.14. Mask necessary areas and prepare for paint

3.15.15. Apply high-temperature silver paint rated for continuous exposure to service temperatures of 300°F or higher

3.16. Prep for Shipment:

3.16.1. Prior to shipping remove gauge, external tubing, etc.

3.16.2. Package loose parts to be shipped with pump

3.16.3. Plug any openings

3.16.4. Verify mechanical seal spacers are in place

3.16.5. Palletize pump in vertical position to minimize tipping during transit

3.16.6. Plastic wrap palletized pump

3.16.7. Tag shipment with Contract Number and correct shipping address

3.16.8. Firm Freight, FOB Destination to be included in the quoted price

3.17. Documentation to be provided:

3.17.1. Detailed final work scope report listing all tasks performed on the pump

3.17.2. Mechanical Seal drawing

3.17.3. Spare parts list for all new parts

3.17.4. As built running clearances

3.17.5. Air test results on assembled pump

3.17.6. Dynamic balance report on impeller

3.17.7. Photographic documentation of key assembly stages

4. Parts Required:

4.1. All parts in the Statement of Work and the Parts Table shall be furnished

4.2. Any additional parts required are to be approved in writing by the Owner or Owner’s Engineer

4.3. Equivalent or upgraded components are acceptable where specified; use of OEM parts is not required unless explicitly stated.

4.4. Common hardware such as fasteners, bearings, and plugs may be procured locally

5. Parts Table:

6. Government Responsibilities:

6.1. Government shall be responsible for shipment of pump to the contractor

6.2. Government shall be responsible for installation of pump

6.3. All plumbing and auxiliary equipment necessary to install the pump to manufacturer recommendations

7. Period of Performance:

7.1. Period of performance will be 140 days from contract award