Attach 1 - Product Description Thrust Bearing Refurbishment 19 Aug.pdf

The Dalles Dam

Generator Thrust Bearing Refurbishment

Contract 19 August 2026

1.0 General Statement

The U.S. Army Corps of Engineers (USACE), Portland District is soliciting for supply contract for full thrust bearing refurbishment for The Dalles Dam located in Klickitat County, Washington. The Contractor shall provide all personnel, equipment, tools, materials, vehicles, supervision, training, and other items necessary to perform the thrust bearing refurbishment as defined in this product requirement. The Contractor shall perform to the standards in the contract and comply with all local, state, and federal regulations during the services performed.

This is a firm fixed price supply contract for refurbishment of one main unit thrust bearing at a time with optional increase in quantity for three additional thrust bearings.

Performance Period & Schedule: The delivery period for the base item (first thrust bearing) shall not exceed nine (9) months from contract award. Each of the three (3) optional quantities, if exercised, shall have an individual delivery period not to exceed nine (9) months from the date of the respective option exercise.

Sequence of Performance: Options will be exercised sequentially upon the successful completion and delivery of the preceding thrust bearing. This phased schedule is designed to accommodate the installation of the newly refurbished bearing, the subsequent removal of the next bearing, its refurbishment, and return shipping.

Accelerated Delivery Encouraged: While the maximum allowable delivery period for each bearing is nine (9) months, accelerated delivery is highly encouraged to support the government’s objective of refurbishing multiple thrust bearings annually.

The contractor will be required to package and ship the thrust bearings using the original packaging crates that the Army Corps of Engineers used to ship the thrust bearings to the contractor with all shipping costs included in the unit price of the thrust bearing refurbishment.

2.0 Definitions

Throughout this Performance Work Statement (PWS), terms are defined as follows:

Contract Discrepancy Report (CDR): A written record of unsatisfactory performance by the Contractor as observed by the COR.

Contracting Officer (KO): The Government employee who is authorized to enter into, administer, and/or terminate contracts and make related determinations and findings.

Deliverable: Anything that can be physically delivered but may include non-manufactured things such as meeting minutes or reports.

Physical Security: Actions that prevent the loss or damage of Government property.

Government Contract Quality Assurance: the various functions, including inspection, performed by the

Quality Control: All necessary measures taken by the Contractor to assure that the quality of an end product shall meet contract requirements.

Merriam-Webster’s Collegiate Dictionary, 11th edition, shall be the source for the ordinarily accepted meaning

TECHNICAL SPECIFICATIONS

TABLE OF CONTENTS GENERATOR THRUST BEARING SHOES

REFURBISHMENT

PART 1 GENERAL

1.1 GENERAL INFORMATION

1.1.1 Description of Work

1.1.2 Description of Thrust Bearing

1.1.3 Equipment Description

1.2 REFERENCES

1.3 DEFINITIONS

1.4 SUBMITTALS

1.5 FINAL INSPECTION AND ACCEPTANCE

1.6 MEASUREMENT AND PAYMENT

1.7 WARRANTY

PART 2 PRODUCTS

2.1 MATERIALS

2.1.1 Bronze for Plugs

2.2 BABBITTING MATERIALS

2.3 ISO CERTIFICATION

PART 3 EXECUTION

3.1 SHIPPING

3.1.1 Shipping Requirements

3.2 REFURBISHMENT OF THRUST BEARING SHOES

3.2.1 Specific Inspection Instructions

3.2.2 Shoes

3.2.3 Inspections

3.2.4 General Refurbishment Requirements

3.2.5 Refurbishment Including Babbitting

3.3 BABBITT BOND NDT

3.3.1 General

3.3.2 UT Inspectors Qualifications

3.3.2.1 Examination of Babbitt Bonding

3.3.2.2 Technician(s)

3.3.3 Equipment

3.3.4 Procedure

3.3.5 Liquid Penetrant (PT) Testing

3.3.6 Acceptance Standards

3.3.7 Babbitt Repairs

3.3.8 Babbitt Bond Acceptance

GENERATOR THRUST BEARING SHOES REFURBISHMENT

PART 1 GENERAL

1.1 GENERAL INFORMATION

1.1.1 Description of Work

The scope of work for this Contract consists of the Contractor furnishing all supervision, engineering, labor, materials, and equipment to perform the following work in strict accordance with the detailed requirements of this Contract:

a. Refurbish one General Electric Thrust Bearing with an option for three additional thrust bearings.

b. Provide required contract documentation.

c. Ship and package using materials that are provided by the Army Corps of Engineers, the bearings from and to The Dalles Lock and Dam, Highway I-84, Exit 88, The Dalles, OR 97058.

1.1.2 Description of Thrust Bearing

The complete thrust bearing consists of the rotating thrust collar and attached thrust runner and the stationary thrust shoe assembly. This specification section only covers the refurbishments of the stationary thrust bearing segments or shoes.

The stationary portion of the bearing consists of the 12 steel-backed babbitt segments or shoes which are each supported on pre-compressed springs. The typical shoe segments are a truncated pie shape with dimensions approximately 31.25 inches long, 22 inches wide (at OD), and 9 inches wide (at ID); The ID measures 45 inches and the OD measures 107 inches. The bearing shoes are 2.25 inches thick, including a babbit layer of approximately0.255 inches to the top of the dovetail (0.420 inches to the bottom of the dovetail). The babbitt is of a lead base. Additionally stationary components consist of the high-pressure lift system, cooling water coils and electrical insulation. While these are the typical dimensions of the thrust bearings custom measurements were taken by The Army Corps and very specific cuts will be provided for each thrust bearing.

Dimensions, fits, and estimated weights are based on original design drawings, design criteria, and/or calculations. The Government does not warrant or guarantee that these values are accurate.

1.1.3 Equipment Description

The new end generating units at The Dalles Dam are vertical, Kaplan turbine-driven units, rates at 94, 420 KVA, 0.95 power factor, 85.7 rpm and were originally manufactured by General Electric Company.

1.2 REFERENCES

The publications listed below form a part of these specifications to the extent referenced. The publications are referred to in the text by the basic designation only.

ASME INTERNATIONAL (ASME)

ASME BPVC (2023) Boiler and Pressure Vessel Code; Section V, Nondestructive Examination

ASTM B 23 (2020) Standard Specification for White Metal Bearing Alloys (Known Commercially as "Babbitt Metal")

ASTM E 114 (2020) Standard Practice for Ultrasonic Pulse-Echo Straight-Beam Examination by the Contact Method

ASTM E 165 (2023) Standard Test Method for Liquid Penetrant Examination AMERICAN SOCIETY FOR

NONDESTRUCTIV TESTING (ASNT)

ASNT-TC-1A (2024) Personnel Qualification and Certification in Nondestructive Testing

1.3 SUBMITTALS

Government coordination is required for all submittals and the listed time frames should be adhered to ensure refurbishment timeframes are met.

SD-01 Prework Submittals

Schedule for Thrust Bearing Shoe Refurbishment; Submit the schedule and list of tasks 21 calendar days in advance of refurbishment, paragraph 3.2.4.d.

Thrust Bearing Shoe Refurbishment Procedure; Submitted for all phases of the shoes' refurbishment a minimum of 21 days in advance of the beginning of the work. The schedule shall be updated and revised as required, paragraph 3.2.5.d.

SD-02 Shop Drawings

Thrust Bearing Shoe Drawing; Submit at least 5 calendar days from as received inspection of Thrust Bearing Shoes, paragraph 3.2.4.b.

SD-03 Product Data

Inspection Sketches and Check Sheets Template; Submit at least 14 calendar days prior to commencing their use, paragraph 3.2.3.b.

Chemical Analysis of the Babbitt and Tin; Submit 7 calendar days prior to tinning, paragraph

2.2.d.

Material Certification Report; Submit 14 calendar days prior to using the material, paragraph 2.1.

Rust Resisting Compound; Submit at least 30 calendar days prior to use, paragraph 3.1.b.

SD-06 Test Reports As Received Inspection; Communicate at most 14 calendar days post inspection, paragraph 3.2.3.a

Pre-Babbitt Inspection Report; Submit at least 14 calendar days prior to babbitting, paragraph 3.2.3.b.

Inspection Notification; Submit within 14 calendar days in advance of Contractor’s shop inspection, paragraph 3.2.3.c

Finished Inspection Report; Submit upon completion of shoe machining, paragraph 3.2.3.c.

NDT Inspection Report; Submit within 5 calendar days of completing the final inspection, paragraph 3.2.3.d.

Final Inspection Report; Submit within 5 calendar days of completing the work, paragraph 3.2.3.d

SD-07 Certificates

Inspection Notification; Submit at least 21 calendar days prior to inspections, paragraph

3.2.3.c. Laboratory Qualifications; Submit at least 30 days prior to use, paragraph 2.2.d.

Proof of ISO 9000 Certification or Equivalence; Submit 14 calendar days following contract award, paragraph 2.3.

NDT Personnel/Laboratory Qualifications; Submit at least 30 calendar days prior to their performance of work, paragraph 3.3.2.1.

SD-08 Manufacturer's Instructions

Tinning and Babbitting Procedure; Submit at least 14 calendar days prior to work, paragraph 3.2.4.c.

Babbitt Repair Procedure; Submit at least 10 calendar days prior to repairs, paragraph 3.3.7.

Required Submittals Submittals Required paragraph SD-01 Schedule for Thrust Bearing Shoe Refurbishment; 3.2.4.d SD-01 Thrust Bearing Shoe Refurbishment Procedure 3.2.5.d

SD-02 Thrust Bearing Shoe Annotated as Built Drawings 3.2.4.b

SD-03 Inspection Sketches and Check Sheets Template; 3.2.1.b and 3.2.3.b

SD-03 Chemical Analysis of the Babbitt and Tin 2.2.d SD-03 Material Certification Report 2.1 SD-03 Rust Resisting Compound 3.1.b

SD-06 As Received Inspection 3.2.3.a SD-06 Pre-Babbitt Inspection Report 3.2.3.b SD-06 Inspection Notification 3.2.1.a and 3.2.3.c

SD-06 Finished Inspection Report 3.2.3.c SD-06 NDT Inspection Report 3.2.3.d

SD-06 Final Inspection Report 3.2.3.d

SD-07 Inspection Notification 3.2.3.c SD-07 Laboratory Qualifications 2.2.d

SD-07 Proof of ISO 9000 Certification 2.3 SD-07 NDT Personnel/Laboratory Qualifications 3.3.2.1

SD-08 Tinning and Babbitting Procedure 3.2.4.c SD-08 Babbitt Repair Procedure 3.3.7

1.4 FINAL INSPECTION AND ACCEPTANCE

Final inspection and acceptance for full compliance with the Specifications will be made by the Government upon delivery to the project. Any materials or workmanship not complying with the provisions of these specifications will be cause for rejection. Corrections shall be made at the expense of the Contractor and are subject to approval. Tests may be repeated at the project site to ensure that materials and workmanship conform to contract requirements. Tests will be at the Contractor's expense if the refurbished components do not meet contract requirements.

1.5 MEASUREMENT AND PAYMENT

PART 1 GENERAL

1.1 GENERAL INFORMATION

In each instance, the contract price for an item will constitute full compensation as herein specified, as shown, or as otherwise approved. The contract price and payment will also constitute full compensation for all work incidental to completion of the item, unless such work is otherwise specifically mentioned for separate payment under another item. In the event any work is required by the specification sections or by the drawings and not specifically mentioned in the measurement and payment paragraphs, separate or direct payment will not be made, and all costs thereof are incidental to, and included in, the contract prices and payment for all items listed in the bid schedule.

1.2 MEASUREMENT

1.2.1 Job Measurement Items

Measurement items for the work of this contract for which contract job payments will be made are listed in the Price Schedule and described below. All costs for items of work, which are not specifically mentioned to be included in a particular job or unit price EA measurement item, shall be included in the listed job item most closely associated with the work involved. The job price for each item listed shall constitute full compensation for furnishing all plant, labor, materials, and equipment, and performing any associated Contractor quality control, environmental protection, meeting safety requirements, tests and reports, and for performing all work required for which separate payment is not otherwise provided.

1.2.2 Unit Price Measurement Items

Measurement items for the work of this contract on which the contract unit price payments will be made are listed in the bid schedule and described below. The unit price for each item listed shall constitute full compensation for furnishing all plant, labor, materials, and equipment, and performing any associated Contractor quality control, environmental protection, meeting safety requirements, tests and reports, and for performing all work required for each of the unit price items.

1.3 CONTRACT ADMINISTRATION AND INVOICING

1.3.1 Contract Administration. Contract will be administered by following:

Department of the Army, Portland District, Corps of Engineers P. O. Box 2946 Attn: CECT-NWP-S Portland, Oregon 97208-2946 Contracting Officer: Suzanne W Hunt, Suzanne.W.Hunt@usace.army.mil Contract Specialist: Nathean Stoner, Nathean.w.stoner@usace.army.mil Technical POC: Nicholas Bowman Phone: 541-506-8314 email: John.N.Bowman@usace.army.mil

1.3.2 Invoice Submittals. Invoice(s) shall be prepared in accordance with FAR clause 52.212-4(g).

Submit original electronic PDF Invoice to the USACE Finance Center via email to:

CEFC-G2invoices@usace.army.mil Email PDF Invoice to Technical POC and Invoice Approver to be determined after award.

mailto:Suzanne.W.Hunt@usace.army.mil mailto:Nathean.w.stoner@usace.army.mil mailto:John.N.Bowman@usace.army.mil mailto:CEFC-G2invoices@usace.army.mil

1.6 WARRANTY

Warranty provisions of these Specifications shall apply to any refurbished part, except that notwithstanding inspection and acceptance, the finished components shall be warranted to conform to these specifications for three years after receipt and acceptance at delivery site or 8000 hours of unit operation after installation, whichever comes first.

PART 2 PRODUCTS

2.1 MATERIALS

The classification and grade of material incorporated in the work shall be in accordance with the specifications designated herein, unless otherwise accepted in writing. All materials shall meet or exceed the standards as specified herein. When two or more of these standards apply, the most stringent standard shall be used. All materials, parts, and components supplied shall be new and unused and of the best available kind and quality.

Workmanship shall be of the highest grade and in accordance with the best modern standard practice.

An independent Material Certification Report shall be submitted at least 14 calendar days prior to use of the material to verify conformance with these specifications.

2.1.1 Bronze for Plugs

Bronze for plugs shall be of a quality at least equal to that required by ASTM B21/B21M UNS C46400.

2.2 BABBITTING MATERIALS

a. The babbitt metal shall be new material conforming to ASTM B 23 Alloy 2.

b. The tin used for tinning shall be 99 percent pure.

c. Use of reclaimed metal will not be acceptable.

d. The Contractor shall submit a Chemical Analysis of the Babbitt and Tin prepared by an independent testing laboratory, 7 calendar days prior to use of the babbitt. The laboratory shall not be associated with the Contractor. The Contractor shall submit the chemical analysis Laboratory Qualifications, at least 30 days prior to use. This submittal shall include all contact information for the laboratory.

2.3 ISO CERTIFICATION

The workshop where the thrust bearing will be refurbished shall be ISO 9000 certified or equivalent as approved by the government. Proof of ISO 9000 Certification or Equivalence shall be submitted to the Government within 14 calendar days following contract award.

PART 3 EXECUTION

3.1 SHIPPING

The following general requirements apply to the shipping of the accepted thrust bearing shoes:

a. Prior to shipping cover all inlets and outlets to exclude dirt, water, etc. All components shall be prepared for shipment in a manner to protect them from damage and the Contractor shall be responsible for and make good at no extra cost to the Government damage resulting from improper preparation, as well as for damage occurring during inspection, shipping, or refurbishment. The Contractor is responsible for damage occurring during all shipping including damage to the shipping crates.

b. After satisfactory inspection, all surfaces shall be coated with a protective filming agent which is suitable to withstand shipping and long-term storage of at least 10 years, such as Glyptal 1202.

Submit product data for the Rust Resisting Compound chosen by the Contractor at least 30 calendar days prior to use. All holes, inlets and outlets shall be cleaned and covered to exclude dirt, water, etc.

c. The crates and all packaging shall become the property of the Government. The shoes are held in place in the crate by bolts. The bolts are not intended to assist in lifting the shoes.

3.1.1 Shipping Requirements

a. The Contractor shall use the same packaging that was used by The Army Corps to ship to the contractor, as required, package for shipment and provide transportation roundtrip for one set of thrust shoes between The Dalles Dam project and the refurbishment workshop.

b. The shipping boxes that were used by the Army Corps to ship to the contractor shall be provided as necessary to assure delivery of the thrust shoes in satisfactory, undamaged condition. Each shoe shall be packaged in a separate box that shall be suitable for handling with a lift truck.

3.2 REFURBISHMENT OF THRUST BEARING SHOES

The thrust bearing shoes are described in Paragraph 1.1.2. The requirements governing the refurbishment of thrust bearing shoes shall apply to an entire set of shoes.

3.2.1 Specific Inspection Instructions

a. The Contractor shall notify the Government 21 days in advance of all inspections by submitting an Inspection Notification. Any inspections may be witnessed by the Government at its discretion.

b. All data shall be recorded on the Contractor-furnished inspection sheets. Contractor-furnished inspection sheets shall be submitted with the Contractor's inspection procedures for approval.

Submit contractor Inspection Sketches and Check Sheets Template at least 14 calendar days prior to their use. Perform the following inspections and submit the preliminary reports prior to the final inspection.

c. At the completion of all required inspections a report of findings shall be submitted including the

Contractor's recommendations for refurbishment.

d. All measurements shall be taken with calibrated instruments accurate to the nearest 0.001 inch unless otherwise indicated. Calibration certification for all equipment shall be furnished with the report of findings.

e. Care shall be taken to protect all surfaces from damage.

f. Clean components as required to perform the required inspections.

3.2.2 Shoes

a. Visual Inspection. All surfaces of each shoe shall be visually inspected, and areas of damage or defects mapped and recorded. Record babbitt and backside surface finish.

b. Backside Flatness. The flatness of the backside shall be checked.

c. Backside Spring Loading Location. On the backside of a shoe spring marks are sometimes visible.

These marks shall be examined and a record made of evidence of non-uniform spring loading and spring movement.

d. Thickness Inspection. Measure thickness at a minimum of 3 locations per shoe (near the shoe I.D., center, and O.D.) in undamaged locations. The results of the measurements and measurement locations shall be submitted to the Government prior to the beginning of any refurbishment as part of the Contractor's detailed refurbishment procedure.

e. Ultrasonic Inspection of Babbitt Bond. Each shoe shall be ultrasonically inspected to determine the degree of bonding between the Babbitt and base metal. This inspection is described in detail in Paragraphs 3.3.1 through 3.3.4.

3.2.3 Inspections

a. As received inspection – The Contractor will perform an As Received Inspection to determine the viability of the shoes for refurbishment, and if any damage occurred in shipment. The equipment status and photos of any damage shall be communicated to the COR within 14 days of bearing shoe receipt.

b. Pre-babbitt inspection – Thrust Shoe Segment Pre-Babbitt Inspection Report. Measurements, checks, and NDT tests shall be performed by the Contractor and recorded on Contractor furnished Inspection Sketches and Check Sheets Template. Perform visual (VT) and liquid penetrant (PT) inspection over the entire surface of each thrust shoe prior to babbitting. All surfaces shall be examined using the liquid penetrant (PT) method. This shall be done using a solvent-removable visible dye and shall be in accordance with ASTM E 165. Verify all features and dimensions. Map defect size and locations. The Contractor shall submit a Pre-Babbitt Inspection Report of findings at least 14 calendar days prior to babbitting and shall not proceed with babbitting until the report is accepted by the Government.

c. Finished inspection – The Contractor shall submit a Finished Inspection Report when machining of the shoes is complete.

1) The finished thrust shoes shall be inspected for the purpose of verifying the requirements

(flatness, runout, thickness, and surface finish) listed in the tolerance sheets at the end of this section.

2) The inspection shall include the NDT of the babbitt-to-shoe bond, as specified in Paragraph 3.2.3.d.

3) The Contractor shall furnish an Inspection Notification to the Government 21 calendar days in advance of all inspections and all inspections may be witnessed by the Government at its discretion.

4) All measurements shall be taken with calibrated instruments to the nearest 0.001 inch, unless otherwise indicated. Calibration certification for all equipment shall be furnished with the report of findings.

5) All data shall be recorded on the Contractor-supplied inspection sheets which shall be provided to the Government inspector prior to departure from the Contractor's facilities.

d. Final reports – The Contractor shall submit a Final Inspection Report to the COR to include all final witnessed measurements, inspections, babbitt analysis, instrument calibration report, and miscellaneous checks, recorded on the accepted Inspection Sketches and Check Sheets within 5 calendar days of completing the final inspection. The final report shall be accepted prior to shipment of the bearing shoes, unless directed otherwise. The Contractor shall wait for written release from the COR for shipment.

A written NDT Inspection Report from the independent laboratory, whether they perform or witness the testing, shall be submitted as part of the final report. The report shall include a complete description of the UT procedures used, equipment used, a mapping of the areas tested, shoe number, and interpretation of results.

The report shall specifically address areas of lack of bond between the babbitt and the shoe and their accumulated total surface area relative to the area allowed for the zone. PT results shall include a mapping of indications at the bond lines or photos. The report shall also address porosity, cracking and other surface defects.

3.2.4 General Refurbishment Requirements

Refurbishment, in this specification, means the Contractor is to remove the existing babbitt material, babbitt machining including the provision of oil supply grooves and other details, machine and/or grind the steel backside of the shoe, re-babbitt the running surface, followed by the finish machining of the babbitt. The refurbishment shall return the shoes to the dimensional tolerances listed in the tolerance sheets at the end of this section. General requirements that apply for all thrust shoe refurbishment options are listed below:

a. No more than 0.020 inches shall be removed from any surface or from the entire thickness of the shoes, unless otherwise approved in writing by the COR or the contracting officer. The Contractor's procedures shall state how this reduction in thickness will impact the thrust bearings operation, if the reduction in thickness should be compensated for, and if so how.

b. The Contractor shall receive a detailed Thrust Bearing Shoe Drawing (DDP-68-35-232) that is to be updated in red ink or red pencil for accuracy and submitted to the COR at least 21 calendar days from receipt of the thrust bearing shoes. The drawing shall show all features and shall be in sufficient scope and detail to permit fabrication of an identical thrust shoe (minus imperfections and wear). The tolerances for decimals shall be to the nearest 0.001 inch and for fractions to the nearest 1/64 inch.

The drawing(s) shall be in CAD (AutoCAD and Inventor are acceptable) and PDF formats.

c. The Contractor shall submit a detailed Tinning and Babbitting Procedure a minimum of 14 calendar days prior to commencing the refurbishment work, including a detailed step-by-step babbitting procedure and the scaled drawing created according to Paragraph 3.2.4.b. The Contractor shall not perform any work until receiving written approval from the Government.

d. A Schedule for Thrust Bearing Shoes Refurbishment, i.e. dates, shall be submitted for all phases of the shoes' refurbishment, a minimum of 14 calendar days in advance of the beginning of the work.

The schedule shall be updated and revised as required. The Government will use this schedule for witnessing refurbishment processes and will notify the Contractor as to which process will be witnessed.

e. The requirements for the refurbished shoes (flatness, runout, thickness and surface finish) are listed on the inspection sheets at the end of this section.

f. Finish dimensions and runout checks shall be made while the shoes are still on the machining table or by an approved method.

g. All high-pressure lift pockets and grooves that existed on the original shoes shall be produced.

h. All non-babbitted surfaces (including the shoe's ID, OD and sides) and holes shall be thoroughly cleaned without the removal of metal, unless approved in writing.

Following the completion of the work, the Contractor shall protect the shoes from damage and corrosion with appropriate coatings and packaging.

3.2.5 Refurbishment Including Babbitting

The Contractor shall refurbish the thrust bearing shoes as specified below. Refurbish means removing the existing babbitt, pouring new babbitt, babbitt machining including the provision of oil supply grooves and other detail, and machining the shoe backside. The refurbishment shall return the shoes to the dimensional tolerances listed in the tolerance sheets at the end of this section.

a. A sample of the babbitt shall be taken and marked for identification at the time that the babbitt is poured. A sample shall be taken for each heat; i.e. if more that one shoe is poured simultaneously, only one sample is required. An independent testing laboratory shall analyze each sample, unless otherwise approved, with the results linked to individual shoes and included in the final report.

b. The Contractor shall prepare the shoes for babbitting according to the procedure approved by the Government. Remove the existing babbitt and tinning material. Machine or shot blast, including dovetail grooves if applicable, and proceed immediately with tinning. Special care shall be taken to protect all holes and surfaces of the shoes not receiving babbitt. Precautions shall be taken to minimize shoe distortion during babbitting.

c. The babbitt shall be poured at a high temperature. The form and shoe shall be pre-heated. The pouring shall be continuous. Cold checks will not be acceptable.

d. The shoes shall be machined and/or ground to the original thickness or the as-measured existing thickness (combined shoe and babbitt thickness), unless otherwise approved. The Contractor's Thrust Bearing Shoe Refurbishment Procedure shall list any additional thickness of babbitt to be added to the shoes. The shoe backside shall be finished prior to finishing the babbitt running surface.

e. The backside of the shoes shall be machined and/or ground as required to remove spring indentations and to achieve the tolerances (flatness, runout, thickness, and surface finish) listed on the tolerance sheets at the end of this section. Material removal shall be uniform over the shoe backside and consistent from shoe to shoe.

f. Machine and/or grind the poured babbitt layer to achieve the tolerances (flatness, runout, thickness, and surface finish) listed on the tolerance sheets at the end of this section. Provide oil supply grooves, radius edges, and other details identical to that found for the existing shoes.

g. Perform Non-Destructive Testing (NDT) of the babbitt bond according to Paragraph 3.3.

h. Additional requirements are listed under Paragraph 3.2.5 above.

3.3 BABBITT BOND NDT

Section 3.3 contains both NDT processes and acceptance criteria. The intent is that the acceptance criteria should only be applied to refurbished shoes and should not be used in non-final inspections. The NDT performed during non-final inspections is not to assess the acceptability of the babbitting work, but rather to provide the Government with information to aid in the evaluation of the shoes existing condition. The acceptance criteria for final inspections of refurbished shoes is contained in Paragraph 3.3.6.

3.3.1 General

The metallurgical bonding of the babbitt to the thrust bearing shoes shall be examined using the Ultrasonic Test (UT) and Liquid Penetrant (PT) method of nondestructive testing. The Pulse-Echo Method of UT inspection shall be employed. Examination shall be made from the babbitt side and 100 percent of the babbitted area shall be inspected. UT examination shall be performed in accordance with the applicable portions of ASTM E 114 or of Article 5 of the ASME BPVC SEC V. The UT procedure which is to be used shall be submitted for approval. The Government at its discretion may witness any inspections.

3.3.2 UT Inspectors Qualifications

3.3.2.1 Examination of Babbitt Bonding

An examination to determine the integrity of the babbitt-to-base metal bond, and to detect porosity and babbitt cracking, shall be performed by an approved independent testing laboratory which is regularly engaged in nondestructive testing, or it may be performed using Contractor personnel. If the examination is performed by Contractor personnel, the Government may require that a representative from an approved independent testing laboratory be present during the examination to witness and certify the results. The laboratory shall be a member in good standing of the American Council of Independent Laboratories (ACIL). The laboratory shall be mutually agreeable between the Government and the Contractor. Prior to the performance of any tests, the laboratory name, location and qualifications shall be submitted as part of the NDT Personnel/Laboratory Qualifications submittal.

3.3.2.2 Technician(s)

Technician(s) performing the inspection shall be certified in accordance with the American Society for Nondestructive Testing (ASNT). The inspector who is performing the UT inspection or who is acting as a representative from an independent testing lab shall, as a minimum, be NDT: ASNT-TC-1A level 2 qualified, with a minimum of 3 years of experience at Level 2 in the last 5 years. Prior to the performance of any tests, the inspector's qualifications shall be submitted as part of the NDT Personnel/Laboratory Qualifications submittal. The inspector shall locate bonded and unbonded areas on the "Reference Blocks" in the presence of the Government's quality assurance representative, as well as identify the back reflection and the babbitt interface.

3.3.3 Equipment

The following equipment shall be used:

a. Search Unit.

(1) All testing of the babbitt bond shall be performed with a 5 MHz longitudinal wave crystal.

(2) Transducer diameter shall be between 0.25 inch and 1 inch.

(3) Transducer gloves or delay lines shall be made of Lucite or other materials with similar sonic properties.

b. Couplants used for testing shall be either lightweight oil or glycerin, the viscosity of which is no more than SAE 30 oil.

c. Reference Blocks.

(1) A reference block shall consist of a soundly babbitted steel block with a scanning surface and babbitt thickness representative of the shoes being tested. The block shall be used to set the sensitivity of the instrument. A reference block with artificially unbonded areas shall be provided for comparison of indications for areas showing bond and lack of bond.

(2) Test sensitivity shall be such that the babbitt-to-base material interface is readily identified on the CRT. Details of sensitivity calibration and determination of bonded and unbonded areas shall be defined in the UT procedure.

(3) Reference blocks shall be kept available for frequent reference during actual testing.

3.3.4 Procedure

The entire babbitt surface of each shoe segment shall be scanned, overlapping scan paths by at least 20 percent of the effective transducer width. Scanning rates shall not exceed 3 inches per second; the use of REJECT shall not be allowed. Unbonded babbitt areas will result in an increase in the size of the reflection or indications of multiple reflections at the interface of the babbitt and base metal. Babbitted areas located over anchoring dovetail grooves will be excluded from UT inspection. All unbonded babbitted areas shall be scanned using a 5 MHz/0.25 inch crystal to determine their size and configuration, using the 6 dB drop off method. The outside edges of all unbonded areas shall be marked on the surface of the Babbitt and recorded on inspection sheets.

3.3.5 Liquid Penetrant (PT) Testing The following test shall be performed:

a. All exposed babbitt to backing material bond lines, including dovetails if applicable, shall be examined with the liquid penetrant (PT) method. This shall be done using a solvent-removable visible dye. The purpose of the PT bond line examination is to define the babbitt-to-backing material bond at edges, which the UT examination may not reveal. The PT method that the Contractor proposes to use shall be submitted for approval and shall be in accordance with ASTM E

165. Lack of bond indications greater than 3/4 inches in length shall be marked on the shoes and mapped on inspection sheets or documented in photos.

b. The surface area of the babbitt, including oil grooves, shall be PT examined for cracks and porosity any and all indications recorded on inspection sheets or documented in photos.

3.3.6 Acceptance Standards

Babbitt bond acceptance criteria is defined below as a function of zones:

a. Perimeter and Holes. Zone defined as bond surface area within 1 inch from any edge or hole having an exposed bond line. The maximum dimension of any individual unbonded area shall be less than 1/2 inch, with acceptable unbonded areas located no closer than two inches apart.

(1) For steel backed shoes the total unbonded area shall be no larger than 5 percent of the total zonal area.

(2) For cast iron backed shoes the total unbonded area shall be no larger than 15 percent.

b. Corners. Zone defined as bond surface area within 1 inch from any corner having an exposed bond line. Corners shall have no unbonded areas.

c. Dovetails. Zone defined as the entire surface area over a dovetail. Dovetails are exempt from UT examination.

d. Bond Lines. Defined as exposed lines at the babbitt to base metal interface.

(1) For steel backed shoes, PT indications of lack of bond totaling over 10 percent of the length of a particular edge shall be unacceptable. Any PT detected lack of bond over 3/4 inch in length shall be re-examined by the UT method, using a 0.25 inch diameter transducer. Unbonded areas extending more than 1/8 inch away from an edge shall be unacceptable.

(2) For cast iron backed shoes, bond lines at pressurized edges shall meet the same criteria as for steel shoes. Pressurized edges include pressurized oil supply grooves/holes, split lines, etc. Bond lines at unpressurized edges, are exempt from PT examination. Unpressurized edges include shoe edges, unpressurized grooves, etc.

e. Remainder of Shoe. Zones are defined as bond surface area other than perimeters, holes, corners and dovetails. The maximum area for any individual unbonded area shall be less than 1 square inch or 3 percent of the total zonal area, whichever is less. Acceptable unbonded areas shall be located no closer than 2 inches apart.

(1) For steel backed shoes the total unbonded area shall be no larger than 5 percent of the total zonal area.

(2) For cast iron backed shoes the total unbonded area shall be no larger than 15 percent.

f. Additional Requirements. The babbitt surface shall have no visible porosity, blow holes, shrinkage, or cracks. The exposed bond line shall have no visible de-bonding.

3.3.7 Babbitt Repairs

If repairs are required to the babbitt surface or to the babbitt-to-backing material interface a Babbitt Repair Procedure shall be submitted at least 10 calendar days prior to repairs, if not already submitted as part of the rebabbitting procedure. Puddling will be acceptable for small areas on the surface, and to correct a localized lack of bond between the babbitt and backing material; however, the total lack of bond repaired by puddling shall not exceed 10 percent of the total babbitted surface.

3.3.8 Babbitt Bond Acceptance

If a shoe's babbitt bond does not meet the above acceptance criteria it shall be repaired or completely rebabbitted and retested at the Contractor's expense until the bond is acceptable in accordance with these specifications.

THRUST BEARING REFURBISHMENT TOLERANCES FOLLOW

TOLERANCES FOR STATIONARY THRUST BEARING SHOE SEGMENTS

GENERATOR THRUST BEARING TOLERANCE SHEETS ADDENDUM

ENTIRE SET MACHINED SIMULTANEOUSLY IN ONE SETUP

1. CIRCUMFERNTIAL RUNOUT

A DIAL INDICATOR ACCURATE TO 0.0001 INCHES SHALL BE MOUNTED IN THE HEAD

OF THE MACHINE TOOL WITH THE STEM OF THE INDICATOR RESTING ON AN

INDIVIDUAL SHOE’S BABBITTED SURFACE. THE MACHINE TABLE SHALL THEN BE

SLOWLY ROTATED AND READINGS TAKEN WHEN THE STEM IS ON EACH INDIVIDUAL

SHOE. VARIATIONS ON AN INDIVIDUAL SHOE AND AMONG THE SET OF SHOES SHALL

NOT BE MORE THAN 0.0005 INCHES OVER ONE COMPLETE REVOLUTION OF THE

TABLE. THIS CHECK SHALL BE MADE NEAR THE I.D., CENTER, AND O.D. OF THE

SHOES.

2. DISH FLATNESS

INDIVIDUAL SHOES SHALL BE CHECKED FOR FLATNESS USING A PLANEKATOR

CALIBRATED TO 0.0001 INCHES. THE BABBITTED SURFACE SHALL BE FLAT OR

CONCAVE WITH THE MAXIMUM LOW SPOT IN THE CENTER OF THE SHOE. THE LOW

SPOT SHALL NOT EXCEED 0.0015 INCHES. THIS LOW SPOT SHALL NOT INCLUDE OIL

HOLES, THREADED HOLES, OR OIL GROOVES OR POCKETS. A BABBITTED SURFACE

THAT IS CONVEX (OUTER EDGE OF SHOE LOWER THAN CENTER PORTION OF SHOE) IS

UNACCEPTABLE AND WILL BE REJECTED.

3. FLATNESS OF BACKSIDE

THE BACKSIDE SHALL BE MEASURED FOR FLATNESS USING

APPROVED METHOD AND SHALL BE FLAT WITHIN 0.001 INCHES. A MINIMUM OF 4

MEASUREMENTS ALONG EACH EDGE (1 INCH IN FROM EDGE) AND 2 DIAGONAL

MEASUREMENTS FROM THE I.D. TO O.D. CORNERS SHALL BE TAKEN.

4. VARIATION IN THICKNESS

ALL INDIVIDUAL SHOE THICKNESS MEASUREMENTS SHALL BE WITHIN 0.0005

INCHES. A MINIMUM OF 9 EVENLY SPACED MEASUREMENTS PER SHOE SHALL BE

TAKEN AS SHOWN BELOW, ON 3 CIRCLES CONCENTRIC WITH THE BORE, I.E., NEAR

THE I.D., CENTER, AND O.D. OF THE SHOES.

THE VARIATION OF EACH SHOE TO THE AVERAGE SHOE THICKNESS SHALL NOT

EXCEED 0.0012 INCHES. A MINIMUM OF 9 EVENLY SPACED MEASUREMENTS PER SHOE

SHALL BE TAKEN AS SHOWN BELOW, ON 3 CIRCLES CONCENTRIC WITH THE BORE,

I.E., NEAR THE I.D., CENTER, AND O.D. OF THE SHOES.

5. SURFACE FINISH (SPRING BED DESIGNS)

THE BABBITTED SURFACE AND BACKSIDE OF THE SHOES SHALL HAVE A FINISHED

SURFACE OF 16 AND 63 MICROINCHES OR BETTER, RESPECTIVELY. THE FINISH

SHALL BE MEASURED USING A PROFILOMETER, OR AS APPROVED.TOLERANCES FOR

STATIONARY THRUST BEARING SHOE SEGMENTS SHOES MACHINED SEPARATELY

1. DISH FLATNESS

INDIVIDUAL SHOES SHALL BE MEASURED FOR FLATNESS USING THE SAME

GRANITE TABLE IN CONJUNCTION WITH A PLANEKATOR CALIBRATED TO 0.0001

INCHES. THE GRANITE TABLE SHALL BE CERTIFIED BY ITS SUPPLIER AS FLAT TO

WITHIN 0.0005 INCH. ALL MEASURING DEVICES SHALL BE ACCURATE TO 0.0001

INCHES. THE BABBITTED SURFACE SHALL BE FLAT OR CONCAVE WITH THE

MAXIMUM LOW SPOT IN THE CENTER OF THE SHOE. THE LOW SPOT SHALL NOT

EXCEED THE AMOUNT INDICATED BELOW. THIS LOW SPOT SHALL NOT INCLUDE

OIL HOLES, THREADED HOLES, OR OIL GROOVES OR POCKETS. A BABBITTED

SURFACE THAT IS CONVEX (OUTER EDGE OF SHOE LOWER THAN CENTER

PORTION OF SHOE) IS UNACCEPTABLE AND WILL BE REJECTED.

A MINIMUM OF 7 SWEEP MEASUREMENTS PER SHOE SHALL BE TAKEN: 3 EVENLY

SPACED MEASUREMENTS ON 3 CIRCLES CONCENTRIC WITH THE BORE, I.E., NEAR

THE I.D., CENTER, AND O.D., 2 ALONG THE LEADING EDGE AND TRAILING EDGE OF

THE SHOE, AND 2 FROM THE OPPOSITE CORNERS. SEE SKETCHES BELOW FOR

DIRECTION AND TOLERANCES:

0.0005 INCHES 0.0015 INCHES 0.0015 INCHES

PRIOR TO PERFORMING EACH SWEEP, ZERO THE MEASURING DEVICE USING THE

SAME LOCATION IN THE CENTER OF THE SHOE. REPORT LOW SPOTS AS NEGATIVE

READING AND HIGH SPOTS AS POSITIVE.

2. FLATNESS OF BACKSIDE

THE BACKSIDE SHALL BE MEASURED FOR FLATNESS USING A PLANEKATOR

CALIBRATED TO 0.0001 INCHES AND SHALL BE FLAT WITHIN 0.001 INCHES. A

MINIMUM OF 4 MEASUREMENTS ALONG EACH EDGE (1 INCH IN FROM EDGE) AND 2

DIAGONAL MEASUREMENTS FROM THE I.D. TO O.D. CORNERS SHALL BE TAKEN.

3. VARIATION IN THICKNESS

ALL INDIVIDUAL SHOE THICKNESS MEASUREMENTS SHALL BE WITHIN 0.0005

INCHES. A MINIMUM OF 9 EVENLY SPACED MEASUREMENT PER SHOE SHALL BE

TAKEN AS SHOWN BELOW, ON 3 CIRCLES CONCENTRIC WITH THE BORE, I.E., NEAR

THE I.D., CENTER, AND O.D. OF THE SHOES.

THE VARIATION OF EACH SHOE TO THE AVERAGE SHOE THICKNESS SHALL NOT

EXCEED 0.0012 INCHES. A MINIMUM OF 9 EVENLY SPACED MEASUREMENTS PER

SHOE SHALL BE TAKEN AS SHOWN BELOW, ON 3 CIRCLES CONCENTRIC WITH THE

BORE, I.E., NEAR THE I.D., CENTER, AND O.D. OF THE SHOES.

4. SURFACE FINISH

THE BABBITTED SURFACE AND BACKSIDE OF THE SHOES SHALL HAVE A FINISHED

SURFACE OF 16 AND 63 MICROINCHES OR BETTER, RESPECTIVELY. THE FINISH

SHALL BE MEASURED USING A PROFILOMETER, OR AS APPROVED.