Attachment 4 Specifications AM 0005.pdf

GSU Transformer Supply - Fort Peck, MT and Oahe Dam, SD OA00106

SECTION TABLE OF CONTENTS

DIVISION 48 - ELECTRICAL POWER GENERATION

SECTION 48 19 23.05 26

CLASS II GSU POWER TRANSFORMERS - OAHE DAM

PART 1 GENERAL

1.1 DESCRIPTION OF WORK

1.2 GENERAL ARRANGEMENT AND CONNECTED POWERTRAIN

1.2.1 General Arrangement

1.2.2 Connected Powertrain

1.3 REFERENCED PUBLICATIONS

1.4 SUBMITTALS

1.5 WARRANTY REQUIREMENTS

1.5.1 General Warranty Requirements

1.5.2 Devices Exempt from Transformer Full Warranty Period

PART 2 PRODUCTS

2.1 TYPE AND RATING

2.1.1 General

2.1.2 Transformer Contract Drawings, Limiting Dimensions and

Equipment Arrangement

2.1.3 Requirements

2.1.4 Standard Products

2.1.5 Descriptive Data

2.1.6 Ratings and Electrical Characteristics

2.1.6.1 230KV Transformers

2.1.6.2 115 KV Transformer

2.1.7 Unusual Service Conditions

2.1.8 Impedance Tolerance Between Transformers of Identical Design

2.2 STRUCTURAL DESIGN CRITERIA AND SEISMIC CALCULATIONS

2.2.1 Structural Design Criteria

2.2.2 Seismic Calculations

2.2.3 Anchorage to Concrete Pedestals for Seismic Restraint

2.3 THERMAL DESIGN

2.4 CORE

2.5 WINDINGS

2.6 TANK

2.6.1 Construction

2.6.2 Structural Steel Base

2.6.3 Lifting, Moving and Jacking Facilities

2.6.3.1 Lifting Facilities

2.6.3.2 Moving Facilities

2.6.3.3 Jacking Facilities

2.6.4 Gasketing

2.6.4.1 General

2.6.4.2 Fluoroelastomer Rubber Gaskets

2.6.4.3 Sizing

2.6.5 Valves

2.6.6 Connecting Hardware

2.6.6.1 General

2.6.6.2 Stainless Steel

2.6.7 Steel Pipe and Fittings

2.6.8 Grounding

SECTION 48 19 23.05 26 Page 1

Am-0005

2.6.9 Portable Fall Arrest System

2.6.9.1 Portable Fall Arrest System Anchor Post

2.6.9.2 Anchor Post Accessories

2.6.9.3 Mounting Plates

2.7 COOLING EQUIPMENT

2.7.1 Coolers

2.7.2 Oil Circulating Pumps

2.7.3 Cooling Fans

2.7.4 Power Supply Equipment

2.7.5 Cooling Control Equipment

2.8 BUSHINGS

2.8.1 General Bushing Requirements

2.8.2 High-Voltage and High-Voltage Neutral Bushings

2.8.2.1 High-Voltage Bushing Ratings (230 kV Transformers)

2.8.2.2 High-Voltage Bushing Ratings (115 kV Transformer)

2.8.2.3 High-Voltage Neutral Bushing Ratings (All transformers)

2.8.3 Low-Voltage Bushings

2.8.4 High-Voltage and Neutral Bushing Terminals and Connections

2.8.5 Low-Voltage Bushing Terminal Connections

2.8.6 Core Ground Bushings

2.8.7 SFRA Test Shipping Bushings

2.8.8 Shipment and Storage

2.8.8.1 Shipment

2.8.8.2 Storage

2.9 BUSHING-TYPE CURRENT TRANSFORMERS

2.9.1 230KV Transformers

2.9.1.1 High-Voltage Bushing Current Transformers

2.9.1.2 Low-Voltage Bushing Current Transformers

2.9.1.3 High-Voltage Neutral Bushing Current Transformers

2.9.2 115KV Transformer

2.9.2.1 High-Voltage Bushing Current Transformers

2.9.2.2 Low-Voltage Bushing Current Transformers

2.9.2.3 High-Voltage Neutral Bushing Current Transformer

2.10 LOW-VOLTAGE BUSHING THROAT FLANGE

2.11 TRANSFORMER MOUNTED ACCESSORIES

2.11.1 General

2.11.2 Liquid Level Indicator

2.11.3 Thermowells

2.11.4 Analog Temperature Indicating Equipment

2.11.4.1 Liquid Temperature Indicator

2.11.4.2 Winding Temperature Equipment

2.11.5 Rapid Pressure Rise Relay and Seal-in Relay

2.11.5.1 Rapid Pressure Rise Relay

2.11.5.2 Seal-in Relay

2.11.5.3 Field Test Kit

2.11.6 Pressure Relief Device

2.11.6.1 General

2.11.6.2 Oil Discharge Piping

2.11.7 On-line Dissolved Gas and Moisture Content Monitor

2.11.7.1 General

2.11.7.2 Features

2.11.7.3 Communication and Data

2.11.7.4 Accessories and Features to be Included

2.11.8 De-Energized Tap Changer Control

2.11.9 Oil Flow Indicators and Switches

2.11.10 Contacts and Devices

2.12 INSULATING OIL

2.12.1 Quantity and Transformer Oil Certification

2.12.2 Type of Oil

SECTION 48 19 23.05 26 Page 2

2.12.3 Chemical, Physical and Electrical Characteristics

2.12.4 Sampling

2.12.5 Testing

2.13 OIL PRESERVATION SYSTEM

2.13.1 Inert-Gas Pressure System

2.13.1.1 Special Site Conditions

2.13.1.2 General

2.13.1.3 Pressure Regulating Equipment

2.13.1.4 Alarm functions

2.13.1.5 Enclosure

2.14 TRANSFORMER CONTROL AND POWER CABINETS

2.14.1 General

2.14.2 Cabinet Mounting and Conduit Interface Provisions

2.14.3 Control Cabinet Requirements

2.14.4 Power Cabinet Requirements

2.14.5 Device Nameplates

2.15 CONTROL AND POWER CABINET EQUIPMENT

2.15.1 Cooling Control Equipment

2.15.1.1 General

2.15.1.2 Stages of Cooling

2.15.2 Transformer Monitor with Cooling Control

2.15.2.1 General

2.15.2.2 Features

2.15.2.3 Monitoring Functions

2.15.2.4 Control Functions

2.15.3 Fiber-Optic Winding Temperature Monitor

2.15.3.1 General

2.15.3.2 Features

2.15.3.3 Monitoring Functions - 230kV Single-Phase Transformers

2.15.3.4 Monitoring Functions - 115kV Three-Phase Transformer

2.15.3.5 Control Functions

2.15.3.6 Fiber-Optic Probes and Connectors

2.15.4 Local Annunciator Panel

2.15.5 Auxiliary Power Transformer

2.15.6 Magnetic Contactors

2.15.7 Molded-Case Circuit Breakers

2.15.7.1 General

2.15.7.2 Trip Units

2.15.7.3 480 Vac Circuits

2.15.7.4 120 Vac Circuits

2.15.7.5 125 Vdc Circuits

2.15.8 Auxiliary and Interposing Relays

2.15.8.1 Auxiliary Relays

2.15.8.2 Interposing Relay for the Lockout Relay

2.15.8.3 Undervoltage Relays

2.15.9 Lockout Relay

2.15.10 Control and Instrument Switches

2.15.11 Terminal Blocks

2.15.11.1 Control Signal Type

2.15.11.2 Short-Circuiting Type

2.15.11.3 Power Distribution Blocks

2.15.12 Fuses and Fuseholders

2.15.13 Lighting, Convenience Receptacle, and Cabinet Heaters

2.16 INSULATED WIRE AND CABLE

2.17 CONDUIT SYSTEMS

2.17.1 General

2.17.2 Corrosion Protection

2.17.3 Conduit and Fittings

2.17.4 Conduit Bodies

SECTION 48 19 23.05 26 Page 3

2.17.5 Conduit Outlet Boxes

2.18 SPARE PARTS

2.18.1 230 KV Single-Phase Transformers

2.18.2 115 KV Three-Phase Transformer

2.19 NAMEPLATES

2.19.1 Transformer Nameplate

2.19.2 Lifting Nameplate

2.19.3 Device Nameplates

2.19.4 Additional Transformer Identification

PART 3 EXECUTION

3.1 TRANSFORMER DESIGN DATA REVIEW MEETING

3.1.1 General

3.1.2 Design Data Review Meeting Requirements

3.2 TRANSFORMER DRAWINGS

3.2.1 Outline and Assembly Drawings

3.2.2 Detail Drawings

3.3 TRANSFORMER FACTORY ASSEMBLY

3.3.1 General

3.3.2 Welding

3.3.2.1 General

3.3.2.2 Welding Quality Control Plan

3.3.2.3 Welder Qualifications

3.3.2.4 Welding Materials

3.3.2.5 Welding Procedures

3.3.2.6 Preheat and Interpass Temperature

3.3.2.7 Weld Inspections, Tests and Weld Inspector Qualifications

3.3.3 Manufacturing Inspection by Government Personnel

3.3.4 Transformer Monitor Setup

3.4 FACTORY CLEANING AND PAINTING

3.4.1 General

3.4.2 Interior Surfaces

3.4.3 Exterior Surfaces

3.4.4 Machined Surfaces

3.5 TRANSFORMER FACTORY ACCEPTANCE TESTS

3.5.1 General

3.5.2 Factory Acceptance Test Report

3.5.3 Dissolved Gas-In-Oil Analysis

3.5.4 Transformer Monitor Tests

3.5.5 Temperature Rise Test

3.5.6 Core Insulation Resistance

3.5.7 Impulse Tests

3.5.8 Induced Voltage Test With Partial Discharge Measurements

3.5.8.1 General

3.5.8.2 7,200 Cycle Enhancement Level

3.5.8.3 One-Hour Level

3.5.8.4 Data Reporting

3.5.9 Audible Sound Level Test

3.5.10 Zero-Phase Sequence Impedance

3.5.11 Leak Test

3.5.12 Leakage Reactance Measurement Test

3.5.13 Sweep Frequency Response Analysis Tests

3.5.13.1 Required Tests

3.5.13.2 Test Equipment and Test Parameters

3.5.13.3 Test Cable Integrity

3.5.13.4 Test Connections

3.5.13.5 Data Reporting

3.5.13.6 Data Interpretation

SECTION 48 19 23.05 26 Page 4

3.5.14 De-Energized Tap Changer Test

3.5.15 Insulated Wire and Cable

3.6 BUSHING TESTS

3.6.1 General

3.6.2 Bushing Design Tests

3.6.3 Bushing Withstand Test Voltages

3.6.4 Bushing Routine Tests

3.6.5 Bushing Current Transformer Tests

3.6.5.1 Routine Tests

3.6.5.2 Tests Performed After Installation

3.7 TRANSFORMER SHIPMENT, HAULING AND SITE ASSEMBLY

-- End of Section Table of Contents --

SECTION 48 19 23.05 26 Page 5

SECTION 48 19 23.05 26

CLASS II GSU POWER TRANSFORMERS - OAHE DAM

PART 1 GENERAL

1.1 DESCRIPTION OF WORK

This Section covers the manufacturing and factory testing of ten generator step-up (GSU) power transformers for delivery f.o.b. Oahe Dam power plant, as identified below. The transformer shipment, hauling, site reassembly, field testing and coordination with a separate installations contractor are as required in SECTION 48 20 00.05 26, "TRANSFORMER SHIPMENT HAULING AND SITE ASSEMBLY - OAHE DAM". Throughout this Section, the transformer tank layout is identified by Segments 1 through 4, as defined in IEEE C57.12.10 , Figure 1, and indicated on the drawings. The contract drawings which are applicable to Oahe Dam are as listed in paragraph, "Transformer Contract Drawings, Limiting Dimensions and Equipment Arrangement". All requirements indicated herein are applicable to all transformers manufactured, unless otherwise specifically indicated.

a. One three-phase transformer rated 103,000 kVA, 115 kV high-voltage (H), 13.8 kV low-voltage (X), Class OFAF *Am-5 or ODAF **Am-5 cooling

b. Nine single-phase transformers rated 68,667 kVA, 230/132.790 kV high-voltage (H), 13.8 kV low-voltage (X), Class OFAF *Am-5 or ODAF **Am-5 cooling

1.2 GENERAL ARRANGEMENT AND CONNECTED POWERTRAIN

1.2.1 General Arrangement

The transformers specified in this Section are to replace ten existing transformers presently located at the Oahe Dam power plant draft tube deck, elevation 1456.0, as identified below. Reference drawings MO-OPN84E170, MO-OPN84E171.1 and MO-OPN84E177.1 show the locations of the existing transformers. The new transformers are to be designed and manufactured as required herein, for installation in the same locations as the existing transformers to be replaced on the draft tube deck.

Interconnection of the transformers to power plant equipment will be performed by a separate contractor.

a. Transformer T1: ASEA circa 1961. One three-phase transformer rated 103,000 kVA, 115 kV high-voltage (H), 13.8 kV low-voltage (X), Class FOW cooling

b. Transformer bank T2: ASEA circa 1961. Three single-phase transformers rated 68,667 kVA, 230/132.790 kV high-voltage (H), 13.8 kV low-voltage (X), Class FOW cooling

c. Transformer bank T3: ASEA circa 1961. Three single-phase transformers rated 68,667 kVA, 230/132.790 kV high-voltage (H), 13.8 kV low-voltage (X), Class FOW cooling

d. Transformer bank T4: ASEA circa 1961. Three single-phase transformers rated 68,667 kVA, 230/132.790 kV high-voltage (H), 13.8 kV low-voltage (X), Class FOW cooling

SECTION 48 19 23.05 26 Page 6

1.2.2 Connected Powertrain

The new three-phase transformers are to be sized per the requirements of paragraph, "Ratings and Electrical Characteristics". The transformers will transmit the power of the connected hydrogenerators, as identified below.

a. Transformer T1: One generator, maximum output of 102,895 kVA,

0.95 pf.

b. Transformer bank T2: Two generators, each with maximum output of 102,895 kVA, 0.95 pf.

c. Transformer bank T3: Two generators, each with maximum output of 102,895 kVA, 0.95 pf.

d. Transformer bank T4: Two generators, each with maximum output of 102,895 kVA, 0.95 pf.

1.3 REFERENCED PUBLICATIONS

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN SOCIETY OF CIVIL ENGINEERS (ASCE)

ASCE 7-22 (2020) Minimum Design Loads and Associated Criteria for Buildings and Other Structures

ASME INTERNATIONAL (ASME)

ASME B1.1 (2019) Unified Inch Screw Threads (UN and UNR Thread Form)

ASME B1.20.1 (2013; R 2018) Pipe Threads, General Purpose (Inch)

ASME B16.1 (2020) Gray Iron Pipe Flanges and Flanged Fittings (Classes 25, 125, and 250)

ASME B16.24 (2022) Cast Copper Alloy Pipe Flanges, Flanged Fittings, and Valves (Classes 150, 300, 600, 900, 1500, and 2500)

ASME B31.1 (2022) Power Piping

ASME BPVC SECTION IX (2023) Qualification Standard for Welding, Brazing, and Fusing Procedures; Welders;

Brazers; and Welding, Brazing and Fusing Operators - Welding, Brazing and Fusing Operators

AMERICAN SOCIETY FOR NONDESTRUCTIVE TESTING (ASNT)

ASNT CP-189 (2020) Qualification and Certification of Nondestructive Testing Personnel

SECTION 48 19 23.05 26 Page 7

ASTM INTERNATIONAL (ASTM)

ASTM A53 (2024) Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless

ASTM A123/A123M (2017) Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products

ASTM A153/A153M (2023) Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware

ASTM A343 (2014; R 2019) Standard Test Method for Alternating-Current Magnetic Properties of Materials at Power Frequencies Using Wattmeter-Ammeter-Voltmeter Method and 25-cm Epstein Test Frame

ASTM A475 (2022) Standard Specification for Metallic-Coated Steel Wire Strand

ASTM A664 (2015; R 2022) Standard Practice for Identification of Standard Electrical Steel Grades in ASTM Specifications

ASTM A717 (2012; R 2022) Standard Test Method for Surface Insulation Resistivity of Single-Strip Specimens

ASTM A876 (2017; E 2017) Standard Specification for Flat-Rolled, Grain-Oriented, Silicon-Iron, Electrical Steel, Fully Processed Types

ASTM D923 (2015; R 2023) Standard Practice for Sampling Electrical Insulating Liquids

ASTM D1418 (2022) Standard Practice for Rubber and Rubber Lattices - Nomenclature

ASTM D1533 (2020) Standard Test Method for Water in Insulating Liquids by Coulometric Karl Fischer Titration

ASTM D1535 (2014; R 2023) Standard Practice for Specifying Color by the Munsell System

ASTM D3487 (2016; E 2017) Standard Specification for Mineral Insulating Oil Used in Electrical Apparatus

AMERICAN WELDING SOCIETY (AWS)

AWS A2.4 (2020) Standard Symbols for Welding, Brazing, and Nondestructive Examination

AWS D1.1 (2020) Structural Welding Code - Steel

SECTION 48 19 23.05 26 Page 8

AWS D1.6 (2017) Structural Welding Code - Stainless Steel

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)

IEEE 693 (2018) Recommended Practice for Seismic Design of Substations

IEEE C57.12.00 (2021) General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers

IEEE C57.12.10 (2017) Requirements for Liquid-Immersed Power Transformers

IEEE C57.12.70 (2020) Standard Terminal Markings and Connections for Distribution and Power Transformers

IEEE C57.12.80 (2010) Terminology for Power and Distribution Transformers

IEEE C57.12.90 (2021) Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers

IEEE C57.13 (2016) Requirements for Instrument Transformers

IEEE C57.19.00 (2023) General Requirements and Test Procedure for Power Apparatus Bushings

IEEE C57.19.01 (2017) Performance Characteristics and Dimensions for Power Transformer and Reactor Bushings

IEEE C57.91 (2011) Guide for Loading Mineral-Oil-Immersed Transformers and Step-Voltage Regulators

IEEE C57.104 (2019; E 2019) Guide for the Interpretation of Gases Generated in Oil-Immersed Transformers

IEEE C57.113 (2023) Recommended Practice for Partial Discharge Measurement in Liquid-Filled Power Transformers and Shunt Reactors

IEEE C57.149 (2012) Guide for the Application and Interpretation of Frequency Response Analysis for Oil-Immersed Transformers

IEEE C57.152 (2013) Guide for Diagnostic Field Testing of Fluid-Filled Power Transformers, Regulators, and Reactors

SECTION 48 19 23.05 26 Page 9

MANUFACTURERS STANDARDIZATION SOCIETY OF THE VALVE AND FITTINGS

INDUSTRY (MSS)

MSS SP-72A (2010) Ball Valves with Flanged or Butt-Welding Ends for General Service

NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)

NEMA 250 (2020) Enclosures for Electrical Equipment (1000 volts Maximum)

NEMA C80.1 (2020) Electrical Rigid Steel Conduit

(ERSC)

NEMA CC 1 (2018; R 2023) Electrical Power Connection for Substations

NEMA FB 1 (2014) Fittings, Cast Metal Boxes, and Conduit Bodies for Conduit, Electrical Metallic Tubing, and Cable

NEMA ICS 2 (2000; R 2020) Industrial Control and Systems Controllers, Contactors and Overload Relays Rated 600 Volts

NEMA ICS 5 (2017) Industrial Control and Systems:

Control-Circuit and Pilot Devices

NEMA MW 1000 (2023) Magnet Wire

NEMA SG 4 (2009; R 2013) Alternating-Current High-Voltage Circuit Breakers

NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

NFPA 70 (2023) National Electrical Code

UNDERWRITERS LABORATORIES (UL)

UL 248-8 (2011; Rev thru Aug 2020) Low-Voltage Fuses - Part 8: Class J Fuses

UL 360 (2013; Rev thru Jan 2024) Liquid-Tight Flexible Metal Conduit

UL 489 (2016; Rev thru Apr 2019) Molded-Case Circuit Breakers, Molded-Case Switches, and Circuit-Breaker Enclosures

UL 508 (2018; Rev thru Jul 2021) Industrial Control Equipment

UL 508A (2018; Rev thru Jul 2022) Industrial Control Panels

UL 514B (2012; Rev thru Mar 2024) Conduit, Tubing, and Cable Fittings

UL 969 (2017; Rev thru May 2023) Marking and

SECTION 48 19 23.05 26 Page 10

Labeling Systems

UL 1203 (2023; Rev thru Oct 2023) Safety Explosion-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations

UL 1863 (2004; Rev thru Oct 2019) Communications - Circuit Accessories

UL 4248-8 (2024) Fuseholders - Part 8: Class J

U.S. ARMY CORPS OF ENGINEERS (USACE)

EM 385-1-1 (2024) Safety and Occupational Health (SOH) Requirements

U.S. NATIONAL ARCHIVES AND RECORDS ADMINISTRATION (NARA)

29 CFR 1910 (2022) Occupational Safety and Health Standards

29 CFR 1926 (2022) Safety and Health Regulations for Construction

1.4 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only or as otherwise designated. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. Submit the following in accordance with SECTION 01 33 00, "SUBMITTAL PROCEDURES", unless otherwise indicated below:

SD-01 Preconstruction Submittals

Welding Quality Control Plan; G, HDC

Submit for approval the welding quality control plan not later than 60 calendar days prior to the start of tank manufacturing.

(see paragraph "Welding Quality Control Plan").

SD-02 Shop Drawings

a. Outline and Assembly Drawings; G

Submit outline and assembly drawings of the transformers for approval not later than 240 calendar days prior to the start of transformer fabrication to demonstrate that the equipment will conform to the requirements and intent of the specifications.

b. Detail Drawings; G

Submit detail drawings for approval not later than 180 calendar days prior to the start of transformer fabrication to demonstrate that the equipment will conform to the requirements of the specifications.

SD-03 Product Data

SECTION 48 19 23.05 26 Page 11

Submit for approval the product data not later than 120 calendar days prior to the start of transformer fabrication to demonstrate that the welding materials will conform to the requirements of the specifications.

a. Welding Electrodes and Rods; G

b. Shielding Gas; G

SD-05 Design Data

a. Transformer Design Data Review Report; G

Submit for approval a transformer design data review report within 30 calendar days of the design data review meeting, to demonstrate fully that all parts of the equipment will conform to the requirements and intent of the specifications.

b. Descriptive Data; G, HDC

Submit for approval the descriptive data and catalog data of all accessory devices, ancillary equipment and gaskets to be provided with the transformer not later than 180 calendar days prior to the start of transformer fabrication, to demonstrate fully that all parts of the equipment will conform to the requirements and intent of the specifications. (see paragraph "Descriptive Data")

c. Spare Parts List; G, HDC

Submit for approval a listing of all required spare parts to be provided with the transformer not later than 180 calendar days prior to the start of transformer fabrication. (see paragraph

"SPARE PARTS")

d. Structural Design Criteria and Seismic Calculations; G, HDC

Submit for approval the structural design criteria and seismic calculations not later than 60 calendar days after outline and assembly drawing approval. Perform design criteria and calculations utilizing civil or structural engineers who are presently registered professional engineers (PE) in any state or territory of the United States, and provide a cover sheet for the submittal which is stamped or sealed and signed by a PE.

e. Cabinet Heater Sizing Calculations

Submit for approval the calculations which verify the ratings of the transformer control and power cabinet heaters, based upon the cabinet sizes, cabinet material, and the regional ambient temperature conditions, not later than 180 calendar days prior to the start of transformer fabrication. (see paragraph "Lighting, Convenience Receptacle, and Cabinet Heaters").

SD-06 Test Reports

a. Transformer Factory Acceptance Test Report; G, HDC

Submit for approval the transformer factory acceptance test

SECTION 48 19 23.05 26 Page 12 reports for each transformer not later than 14 calendar days following completion of the factory acceptance tests. (see paragraph "Factory Acceptance Test Report").

b. Bushing Design Tests; G, HDC

Submit for approval the transformer bushing design test reports not later than 30 calendar days following completion of the tests (see paragraph "Bushing Design Tests"). If certified copies of bushing design tests previously conducted within ten (10) years are submitted in-lieu of new test results, submit them when the bushing selection is made, but not later than 60 calendar days prior to the performance of transformer factory acceptance tests.

c. Bushing Routine Tests; G, HDC

Submit for approval the transformer bushing routine test reports for each transformer not later than 30 calendar days following completion of the tests. (see paragraph "Bushing Routine Tests").

d. Bushing Current Transformer Manufacturer Routine Tests; G, HDC

Submit for approval the transformer bushing current transformer manufacturer routine test reports for each transformer not later than 30 calendar days following completion of the tests. (see paragraph "Bushing Current Transformer Manufacturer Routine Tests").

e. Weld Inspection and Test Report; G

Submit for approval the weld inspection and test report for each transformer tank not later than 14 calendar days following completion of the weld inspections and tests. (see paragraph "Weld Inspections, Tests and Weld Inspector Qualifications").

SD-07 Certificates

a. Transformer Oil Certification; G, HDC

Submit for approval the transformer oil certification documents a minimum of 14 calendar days prior to the delivery of transformer oil to the Oahe Dam power plant. (see paragraph "Quantity and Transformer Oil Certification").

b. Notification of the Date of the Transformer Design Data Review Meeting; G, HDC

Notify the COR 30 calendar days in advance of when the transformer manufacturer will be ready for performance of a design data review meeting, to be held at the manufacturer's facility.

If the meeting is to be held in a foreign country, notify the COR in writing of the meeting dates a minimum of 60 days prior to the proposed meeting date.(see paragraph "TRANSFORMER DESIGN DATA

REVIEW MEETING").

c. Request for Transformer Monitor Settings and Software Configuration

Request from the COR, in writing, 30 calendar days in advance of

SECTION 48 19 23.05 26 Page 13 when the transformer manufacturer will be ready to install the Government provided Transformer Monitor settings and configuration data for the purposes of quality control functional checks prior to the performance of factory acceptance testing. (see paragraph "Transformer Monitor Setup").

c. Notification of the Date of Factory Tests; G, HDC

Notify the COR, in writing, 30 calendar days in advance of when the transformer will be ready for factory acceptance tests, so that the tests may be witnessed by a Government Representative.

If factory testing in a foreign country is proposed, notify the COR in writing of the preliminary testing dates a minimum of 60 days prior to the start of factory tests. (see paragraph

"TRANSFORMER FACTORY ACCEPTANCE TESTS").

d. Welder Qualifications; G, HDC

Submit for approval the welding operators and welders qualifications a minimum of 60 calendar days prior to their performance of work. (see paragraph "Welder Qualifications").

e. Weld Inspector Qualifications; G, HDC

Submit for approval the qualifications for the Contractor's Quality Assurance personnel responsible for performing weld inspections a minimum of 60 calendar days prior to the performance of weld inspections. (see paragraph "Inspection and Weld Inspector Qualifications").

SD-08 Manufacturer's Instructions

a. Factory Test Procedures; G, HDC

Submit for approval the transformer factory test procedures a minimum of 60 calendar days prior to the performance of the factory acceptance tests. (see paragraph "TRANSFORMER FACTORY

ACCEPTANCE TESTS").

b. Welding Procedures; G, HDC

Submit for approval the welding procedures and specifications, and copies of test reports, a minimum of 60 calendar days prior to the performance of work. (see paragraph "Welding Procedure").

c. Prequalified Weld Procedures; G, HDC

Submit for approval the applicable prequalified weld procedures per the requirements of AWS a minimum of 60 calendar days prior to the performance of work. (see paragraph "Welding Procedure").

1.5 WARRANTY REQUIREMENTS

1.5.1 General Warranty Requirements

In addition to the requirements outlined in FAR 52.246-17, provide a manufacturer’s warranty for the power transformers for a period of 5 years from the date of final acceptance of the work. Provide a warranty certificate for each transformer indicating the date of expiry, to be

SECTION 48 19 23.05 26 Page 14 included in the final Operations and Maintenance Instructions. If the Government takes possession of any part of this work before final acceptance, this warranty is to continue for a period of 5 years from the date the Government takes possession. The following transformer issues will also be considered warranty repair items:

a. Transformer gassing quantities or rates exceeding the DGA status norms as defined in Table 1 of IEEE C57.104 .

b. Transformer oil leaks, at welded joints as well as gasketed connections and valve stem packing.

c. Paint failures resulting in visible loss of adhesion through bubbling, flaking, peeling, or any visible rust due to paint failure.

1.5.2 Devices Exempt from Transformer Full Warranty Period

The following transformer ancillary devices are subject to the device manufacturers standard warranty period, and are exempt from the transformer manufacturer's warranty period:

a. Cooling equipment

b. Bushings

c. Transformer mounted accessories

d. Control and power cabinet equipment

e. Insulated wire and cable

f. Conduit systems

PART 2 PRODUCTS

2.1 TYPE AND RATING

2.1.1 General

The transformers to be furnished under these specifications include one three-phase and nine single-phase, of two-winding design with one high-voltage and one low-voltage winding per phase, oil-immersed type suitable for outdoor operation. The transformers are to be *Am-5 either forced-oil/forced air-cooled type, Class OFAF, or directed-oil/forced air-cooled type, Class ODAF, **Am-5 of a design that has an established record of satisfactory operation with the type of oil preservation system specified, and manufactured suitable for shipment by sea transportation, railcar, and trucking by heavy hauler.

2.1.2 Transformer Contract Drawings, Limiting Dimensions and Equipment Arrangement

The layout, equipment arrangement and dimensional requirements of the transformers are to be as indicated on contract drawings. The transformers for Oahe Dam have contract drawing sheet numbers with a '200 series' designation, as indicated below. Contract drawings which have requirements which are common to both the 115 kV three-phase and 230 kV single-phase transformer designs are included on a the same drawing and indicated as OAHE 230KV AND 115KV TRANSFORMERS.

SECTION 48 19 23.05 26 Page 15

G-201 through G-212: General Drawings

E-201 through E-223: Electrical Drawings

S-201: Structural Drawing

2.1.3 Requirements

Except as otherwise specified herein, the transformers, accessories, and spare parts must conform to the applicable requirements of IEEE C57.12.00 , IEEE C57.12.10 , IEEE C57.12.70 , IEEE C57.12.80 and IEEE C57.12.90 .

2.1.4 Standard Products

Provide material and equipment which are standard products from a manufacturer that is regularly engaged in their production, and are items that have been commercially available for at least 3 years prior to bid opening, unless otherwise specifically approved. All materials must conform to the requirements of these specifications. Materials must be of industrial quality, free from defects and imperfections, presently being manufactured, and of the classification and grades designated. If the contractor desires for any reason to deviate from the standards designated in these specifications, submit for approval a statement describing the exact nature of the deviation, including complete specifications for the materials that are being proposed for use.

2.1.5 Descriptive Data

Submit for approval descriptive data for all transformer equipment, which includes catalog and technical data of sufficient detail to verify conformance with the requirements, herein. Highlight or circle the catalog and technical data for the specific device and model, and provide ordering information and cut sheets. The descriptive data is to include the following at a minimum:

1. Electrical core steel, including country of origin

2. Winding conductors, including country of origin

3. Gasket type and material

4. Valves (each type)

5. Oil sampling device

6. Coolers

7. Cooling fans (including wiring connection methods)

8. Oil pumps

9. Nitrogen regulator cabinet

10. Bushings (each type and rating)

11. Core ground bushings

12. Bushing current transformers

13. Bushing current transformer terminal boxes

14. Thermowells

15. Oil flow indicator with integral switch

16. Oil level indicator

17. Oil temperature indicator

18. Winding temperature indicator, including associated equipment

19. Rapid pressure rise relay, including seal-in relay

20. Dissolved gas analyzer, with all provided fittings

21. Pressure relief device, including discharge piping

22. De-energized tap changer, including operating handwheel

23. Portable fall arrest system and mounting base

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24. Insulating oil, including vendor and inhibitor

25. Control and power cabinet vibration isolators

26. Control cabinet folding computer tray

27. Transformer monitor

28. Fiber-optic winding temperature monitor

28. Fiber-optic probes

29. Fiber-optic tank feed-through plate and connectors

30. Ambient air RTD sensor

31. Annunciator

32. Auxiliary power transformer and mounting cabinet

33. Magnetic contactors

34. Molded-case circuit breakers (each type and rating)

35. 480 Vac circuit breaker locking provisions

36. Auxiliary relays

37. Undervoltage relays

38. Interposing relay for the lockout relay

39. Lockout relay

40. Control and instrument switches

41. Terminal blocks (each type)

42. Fuses

43. Fuse holders

45. Wire duct

46. Cabinet lighting

47. Cabinet door switch

48. GFCI receptacle

49. Cabinet heaters

50. Cabinet grounding busbar

51. Cabinet ventilation

52. Thermostat / humidistat

53. Insulated wire and cable (each type) and signal cable

54. Wire labeling method

55. Device nameplate method

56. Conduit and fittings

57. Junction boxes

58. Impact recorders for shipment (analog & digital)

59. Stainless steel anti-galling compound and Nitronic 60 hardware

2.1.6 Ratings and Electrical Characteristics

2.1.6.1 230KV Transformers

The ratings and electrical characteristics of each 230KV transformer are to be as follows:

a. Continuous rating, at ambient temperature conditions of 45 degrees Celsius (see drawing sheet G-202), on all taps, kVA: 68,667

b. Frequency, Hz: 60

c. Number of phases: 1

d. Rated voltage, kV:

(1) High-voltage windings: 230/132.790

(2) Low-voltage windings: 13.8

e. Winding connections (when connected as a three-phase bank):

SECTION 48 19 23.05 26 Page 17

(1) High-voltage windings: Grounded-Wye

(2) Low-voltage windings: Delta

f. Impedance, at 100-percent OFAF *Am-5 or ODAF **Am-5 rated current, subject to IEEE tolerances, percent: 10.6

g. Polarity: Subtractive

h. Basic impulse insulation levels (BIL), kV:

(1) Line ends of the high-voltage windings, not less than: 900

(2) Neutral ends of the high-voltage windings, not less than:

(3) Low-voltage windings, not less than: 110

i. Taps in low voltage windings: None

j. Taps (full capacity) in high voltage winding

(1) Tap 1, percent of high-voltage rating: 105.0

(2) Tap 2, percent of high-voltage rating: 102.5

(3) Tap 3, percent of high-voltage rating: 100.0

(4) Tap 4, percent of high-voltage rating: 97.5

(5) Tap 5, percent of high-voltage rating: 95.0

k. Maximum average sound level at rated voltage and frequency, with all cooling groups in operation, dB: 70

n. Maximum transformer total weight, completely assembled and oil filled with all accessories installed, pounds: 160,000

o. Maximum transformer total oil volume, completely assembled and oil filled, gallons: 4,700

2.1.6.2 115 KV Transformer

The ratings and electrical characteristics of the 115 KV transformer is to be as follows:

a. Continuous rating, at ambient temperature conditions of 45 degrees Celsius (see drawing sheet G-202), on all taps, kVA: 103,000

b. Frequency, Hz: 60

c. Number of phases: 3

d. Rated voltage, kV:

(1) High-voltage windings: 115

(2) Low-voltage windings: 13.8

e. Winding connections:

(1) High-voltage windings: Grounded-Wye

(2) Low-voltage windings: Delta

f. Impedance, at 100-percent OFAF *Am-5 or ODAF **Am-5 rated current, subject to IEEE tolerances, percent: 13.5

SECTION 48 19 23.05 26 Page 18

g. Angular displacement, low-voltage lags high-voltage by, degrees:

h. Basic impulse insulation levels (BIL), kV:

(1) Line ends of the high-voltage windings, not less than: 550

(2) Neutral ends of the high-voltage windings, not less than:

(3) Low-voltage windings, not less than: 110

i. Taps in low voltage windings: None

j. Taps (full capacity) in high voltage winding

(1) Tap 1, percent of high-voltage rating: 105.0

(2) Tap 2, percent of high-voltage rating: 102.5

(3) Tap 3, percent of high-voltage rating: 100.0

(4) Tap 4, percent of high-voltage rating: 97.5

(5) Tap 5, percent of high-voltage rating: 95.0

k. Maximum average sound level at rated voltage and frequency, with all cooling groups in operation, dB: 70

n. Maximum transformer total weight, completely assembled and oil filled with all accessories installed, pounds: 212,000

o. Maximum transformer total oil volume, completely assembled and oil filled, gallons: 4,400

2.1.7 Unusual Service Conditions

The transformers will be subject to the following unusual service conditions, as defined by IEEE C57.12.00 , paragraph 4.3:

a. As shown on drawing sheet G-202, "REGIONAL TEMPERATURE ANNUAL SUMMARY",the ambient temperature conditions at the Oahe Dam power plant has the following history since 1954. Because of this unusual service condition, the transformers are to be capable of full-load operation at an ambient temperature condition of 45 degrees Celsius.

(1) Maximum recorded temperature, degrees Celsius: 47.2

(2) Maximum daily average temperature, degrees Celsius: 36.4

(3) Occurrence of maximum recorded temperatures above 40 degrees Celsius, days: 206

(4) Occurrence of maximum recorded temperatures between 35 - 40 degrees Celsius, days: 1,229

(5) Occurrence of maximum daily average temperatures above 30 degrees Celsius, days: 246

(6) Occurrence of maximum daily average temperatures between 25 - 30 degrees Celsius, days: 4,905

SECTION 48 19 23.05 26 Page 19

2.1.8 Impedance Tolerance Between Transformers of Identical Design

The impedance tolerance between the 230 kV single-phase transformers is limited to a maximum of 3 percent at the OFAF *Am-5 or ODAF **Am-5 rating, to reduce circulating currents when wye-connected and assure proper operation of the transformer differential relaying.

2.2 STRUCTURAL DESIGN CRITERIA AND SEISMIC CALCULATIONS

Provide Structural design criteria and seismic calculations for the transformers, to include the main tank and all major components such as bushings, cooling equipment, and cabinets.

2.2.1 Structural Design Criteria

Structural design criteria is to include the following:

a. Indicate the industry design standards (ASCE or IEEE) and allowable stresses or capacities to which steel plate, structural steel shapes, welds, bolts and studs conform.

b. Indicate the industry standards (ASCE or IEEE) used in developing the seismic forces and analysis techniques used in design of the transformers and transformer components.

c. Provide the seismic design for equipment restraint in accordance with Chapter 13, "Seismic Design Requirements for Nonstructural Components," of ASCE 7-22 with the seismic design force computed as per Section 13.3 "Seismic Demands on Nonstructural Components".

Provide electrical equipment restraint in accordance with the provisions in IEEE 693 Annex D, or Section 13.3 of ASCE 7-22 whichever produces the more adverse seismic effects. For ASCE 7-22 , use a spectral acceleration S DS = 0.09, I P = 1.5 and z=h=1. For IEEE 693 , the seismic qualification level is to be moderate.

d. Provide wind load calculations based upon Exposure Category "D" of ASCE 7-22 . Base the effect of wind load forces upon ASCE 7-22 , or 40 psf, whichever is greater.

2.2.2 Seismic Calculations

Perform seismic calculations which include the following:

a. Derivation of seismic forces and load cases. Load cases used for developing seismic anchorage of the complete transformers are to account for the effect of the righting force of the weight of the transformers.

b. Calculations for use in the design of anchorage to resist overturning and base shear. Provide the maximum uplift and shear force per anchor calculations in pounds or kips.

c. A schematic depicting the location of the center of gravity, the applied seismic forces relative to the base, and the location of seismic anchors.

d. Calculations for individual components and their attachment to the transformers.

SECTION 48 19 23.05 26 Page 20

2.2.3 Anchorage to Concrete Pedestals for Seismic Restraint

Each transformer is to be manufactured for mounting on a the existing concrete transformer pedestals, with the railing removed and embedded steel plates installed on the top pedestal surfaces. For the purposes of performing seismic calculations, the transformer bases will be welded to steel plates attached to the concrete pedestals, as indicated in paragraph, Structural Steel Base.

2.3 THERMAL DESIGN

The temperature rise above ambient temperature of each transformer or parts thereof, when tested in accordance with its ratings, is not to exceed the limits of observable temperature rise for oil immersed apparatus as stated in IEEE C57.12.00 (paragraph 5.11.1). The winding temperature rise by resistance is not to exceed 65 degrees Celsius, and the hottest spot winding temperature rise is not to exceed 80 degrees Celsius on the tap connections that give the highest losses, with all coolers in operation. In addition, the transformer must not exceed the above temperature rises when tested at 70 percent of rated kVA with one of the cooling groups not in operation. The transformers must be capable of continuous operation at no-load, self excitation conditions with no auxiliary cooling groups in operation, and satisfactory operation with part or all of the auxiliary cooling equipment out of service in accordance with paragraph 9.8 of IEEE C57.91 . Suitable arrangements are to be provided within the transformer to direct the oil from the coolers through the core and coils. The design of the oil flow control system must effectively distribute the amount, direction, and velocity of the oil entering the tank from the coolers through the various portions of the core and coils in accordance with their requirements. A design of oil circulating system that depends solely upon the thermosiphon action of the oil to remove heat from the core or windings will not be acceptable.

2.4 CORE

The transformers' core steel laminations are to be constructed of high-quality, non-aging, cold-rolled, grain-oriented steel especially suitable for the purpose, meeting the requirements of ASTM A664 and ASTM A876, and the following:

a. Lamination maximum thickness of 0.270 mm, and the design flux density less than 1.75 Tesla.

b. Electrical core steel core loss, rms exciting power, rms and peak exciting current, and ac permeability design tested in accordance with ASTM A343, with the design test reports included with the descriptive data.

c. Each roll of sheet steel used is to have the surface insulation resistivity tested in accordance with ASTM A717.

d. The core is to be assembled with interleaved joints, and rigidly clamped to ensure mechanical strength to support the windings and to prevent shifting of the laminations during shipment, and also to reduce vibration during operation.

2.5 WINDINGS

The transformers are to be manufactured with windings meeting the

SECTION 48 19 23.05 26 Page 21 requirements of paragraph "Ratings and Electrical Characteristics", consisting of one high-voltage winding (H) per phase and one low-voltage winding (X) per phase. Consideration must be given to all factors of service, such as high dielectric and mechanical strength of insulation, coil characteristics, and minimum restrictions to free circulation of oil. Coils must be made up, shaped, and braced to provide for expansion, contraction, and shrinkage due to temperature changes and aging in service in order to avoid abrasion of insulation and to provide resistance to movement and distortion caused by abnormal operating conditions. Barriers are to be provided between windings and core and between high-voltage and low-voltage windings. End coils are to have additional protection against normal line disturbances. The windings must meet the following requirements:

a. Winding conductors manufactured from high-conductivity copper magnet wire meeting the applicable requirements of NEMA MW 1000.

b. Winding assembly of a circular coil construction if the transformer is a core-form design.

c. Conductor insulation consisting of thermally upgraded Kraft paper.

d. A de-energized tap changer with taps located in the high-voltage windings. The tap changer contacts are to be silvered, and capable of withstanding the full short circuit current of the transformer without injury.

e. Basic impulse insulation level (BIL) of the windings as specified in paragraph "Ratings and Electrical Characteristics", and capable of withstanding IEEE Standard dielectric tests, in accordance with paragraph "Power Transformer Tests", corresponding to the specified winding insulation levels.

f. Capable of withstanding without injury the mechanical and thermal stresses caused by short circuits on the external terminals of any winding or windings, with rated voltages maintained across the terminals of all other windings intended for connection to sources of energy, under the conditions listed in IEEE C57.12.00 (paragraph 7.1.1).

g. Fiber-optic probes embedded in the calculated hottest spot for each high and low-voltage winding duct spacers for direct winding temperature measurement, with quantities and distribution as required in paragraph "Fiber-Optic Winding Temperature Monitor."

2.6 TANK

2.6.1 Construction

Each transformer is to be manufactured with an oil-tight steel tank, with oil-tight covers per the requirements of IEEE C57.12.10 (paragraph 5.8), with the following features:

a. The main transformer tank and any attached compartment that is subjected to operating pressures, is to be designed and manufactured to withstand an internal pressure of not less than 10 psi without leakage or permanent deformation.

b. Manufactured for vacuum filling (essentially full vacuum) in the

SECTION 48 19 23.05 26 Page 22 field, with all valves, fittings and piping affected by vacuum filling rated for such filling.

c. Welded joints between the tank and cover, and between tank sections, designed to prevent weld splatter from entering the inside of the tank during the welding process.

d. Positioning guides inside the tank to assure the core and windings are in the correct position during the assembly process, and provide additional rigidity during transportation.

e. Unobstructed manholes in the cover (two for the single-phase transformers, and three for the three-phase transformer) with minimum dimensions of 24 inches by 24 inches, or 24 inches minimum diameter, to afford easy personnel access to the inside of the tank and the upper portions of the core and coils.

f. Handhole access covers in the tank sidewall for access to low-voltage bushing bottom connection and the de-energized tap changer switch mechanism for future maintenance.

2.6.2 Structural Steel Base

Each transformer is to be manufactured with an integral structural steel base manufactured for mounting on the existing concrete pedestals, meeting the following requirements:

a. A minimum of six inches in height.

b. Consisting of two skid channels oriented parallel to the high-voltage bushings, and two skid channels oriented perpendicular to the high-voltage bushings, spaced 84-inches on centers, which will be welded on the outer ends to steel plates embedded on top of the concrete pedestals by a separate installations contract after the transformer is placed into position.

c. Manufactured to be suitable for moving on rollers or skids when the transformer is completely assembled and filled with oil, permitting moving the transformer in a direction parallel to either centerline, with suitable pulling eyes provided.

d. Manufactured to withstand seismic forces as required in paragraph

"STRUCTURAL DESIGN CRITERIA AND SEISMIC CALCULATIONS".

2.6.3 Lifting, Moving and Jacking Facilities

2.6.3.1 Lifting Facilities

Design loads for lifting eyes must have a safety factor of five in accordance with IEEE C57.12.10 (paragraph 5.3.1). Lifting eyes must positively keep the lifting cable in place even when the cable is slack.

Each transformer is to be provided with the following lifting facilities:

a. Lifting attachments on the tank cover.

b. Adequate means for lifting the core and coil assembly from the tank.

c. Lifting eyes located at the top of the tank sidewalls manufactured

SECTION 48 19 23.05 26 Page 23 for lifting the complete transformer filled with oil, and allowing for securing of the transformer during shipment.

2.6.3.2 Moving Facilities

Moving facilities are to be furnished in accordance with IEEE C57.12.10 (paragraph 5.3.3).

2.6.3.3 Jacking Facilities

Each transformer is to be manufactured with jacking facilities to permit jacking the fully assembled transformer filled with oil per the requirements of IEEE C57.12.10 (paragraph 5.3.4). The design loads for jacking facilities must be a minimum of two times the actual loads to allow for possible unequal jacking forces.

2.6.4 Gasketing

2.6.4.1 General

Gaskets between metal surfaces are to be set in expansion-limiting grooves so that all contact surfaces are metal-to-metal when tightened. The gaskets are to be made of Nitrile NBR (Buna N) with a Durometer rating between 50 and 70, with the exception that gaskets for the low-voltage bushings are to be fluoroelastomer rubber meeting the below requirements .

Circular cross-section gaskets will not be acceptable for use in gasket grooves of rectangular cross-section.

2.6.4.2 Fluoroelastomer Rubber Gaskets

Fluoroelastomer rubber gaskets are to meet the requirements of ASTM D1418, designation FKM Type 2, and have have the following characteristics:

a. Manufactured with 100-percent virgin FKM fluoroelastomer polymer.

b. Operating temperature range between -20 and +400 Fahrenheit.

c. Durometer hardness of 70 (+/- 2)

d. Fluorine content of 66-percent.

2.6.4.3 Sizing

Nitrile gasket sizing for rectangular cross-section grooves are to be accomplished as follows:

a. Gasket thickness is chosen so that approximately 25-percent of the gasket cross-section protrudes above the depth of the groove, referred to as the 'gasket compression area'.

b. The width of the groove minus the width of the gasket determines the space available for gasket expansion during compression. The amount of groove space available for gasket expansion during the compression process is referred to as the 'gasket expansion area', which must be greater than the gasket compression area to avoid pinching of the gasket between the metal surfaces when tightened.

c. Proper sizing coordination between the gasket groove and the gasket cross-sections results in 25-percent gasket compression, with a

SECTION 48 19 23.05 26 Page 24 remaining gasket expansion area after tightening of between 5 and 10-percent.

2.6.5 Valves

All valves must conform with IEEE C57.12.10 (paragraph 5.1.8), be of ball-type stainless steel construction conforming to MSS SP-72A, circular flanged mounting, with reinforced PTFE valve seats, unless otherwise specifically indicated. The valves are to be of full-port design, designed for use with insulating oil with a 120 degrees Celsius minimum temperature rating and include hasps for locking the handle. Valves for each transformer are to be provided for the following:

a. Upper filter connection . A 2-inch valve with a 2-inch female NPT threaded open-end connection and a threaded plug, located on the Segment 4 tank sidewall such that it can be used to fill the transformer with oil while the transformer is under vacuum.

b. Vacuum pump connection . A 3-inch valve with a 3-inch circular-flanged open-end connection, located on the tank cover for use in connecting a vacuum pump during the vacuum filling process.

Provide a gasketed blind flange cover with an integral 3-inch NPT female connection and threaded plug for the valve open-end connection.

c. Main drain . A 3-inch valve with a 3-inch circular-flanged open-end connection, located at the extreme bottom of the tank on Segment 2 tank sidewall for use in gravity draining of the transformer. Provide a gasketed blind flange cover with an integral 3-inch NPT female connection and threaded plug for the valve open-end connection.

d. Oil sampling valve . A 1-inch valve, with a 1/2-inch NPT threaded open-end connection and a 1/2-inch threaded sampling device, complete with protective cover, located at the bottom of the tank on Segment 2 tank sidewall for the purposes of obtaining oil samples. An example sampling device is that made by United Brass Works Model 86.

e. Lower filter connection . A 2-inch valve with a 2-inch female NPT thread open-end connection and a threaded plug, located at the extreme bottom of the…