STATEMENT OF WORK DWTP 3.pdf

STATEMENT OF WORK (SOW)

Project: Heavy-Duty Deep Well Turbine Pump Overhaul and 18” Wellbore Rehabilitation System Specifications: 18" Casing, notional 150 HP Motor, 560' Pump Setting, and 1050

GPM @ 580' TDH

Location: Luke AFB AZ, Water Well Number 12

1.0 OBJECTIVE & SCOPE

The Contractor shall furnish all labor, materials, heavy rigging (crane operations), and engineering supervision necessary to extract, overhaul, and reinstall one (1) Deep Well Turbine Pump (DWTP) set at approximately 560 feet. The Contractor shall rebuild the 150 HP surface motor, overhaul the bowl assembly to meet the design point of 1050 GPM at 580 feet Total Dynamic Head (TDH), rehabilitate the 18-inch wellbore, and commission the system to Department of War (DoW) and Air Force standards.

2.0 APPLICABLE PUBLICATIONS & TECHNICAL STANDARDS

All work shall comply with the latest editions of:

Authority Standard Title / Subject

DoD UFC 3-230-02 O&M: Water Supply Systems

Air Force AFI 32-1067 Water and Fuel Systems

USACE EM 385-1-1 Safety & Health Requirements Manual (Rigging & LOTO)

AWWA AWWA A100 Standard for Water Wells

AWWA AWWA E101 Vertical Turbine Pumps - Line Shaft Types

3.0 TECHNICAL TASK REQUIREMENTS

🏗🏗 Task 1: Mobilization, Crane Rigging, and Safety (LOTO)

• Heavy Rigging: Due to the suspended weight of 560 feet of column pipe, line shaft, and bowl assembly, the Contractor shall utilize a certified crane or heavy-duty pump hoist rated for the total static and dynamic extraction load. A critical lift plan must be submitted if required by Base Safety per EM 385-1-1.

• Electrical LOTO: Coordinate with Base Civil Engineering (BCE) to disconnect and physically Lockout/Tagout the 150 HP motor control center (MCC).

🪝🪝 Task 2: Extraction and Inspection

• Extract the 150 HP motor, discharge head, 560 feet of column pipe, line shafting, and the pump bowl assembly.

• Match-mark and thread-gauge all line shaft couplings and column pipe joints during extraction.

⚙ Task 3: Surface Equipment Overhaul (150 HP Motor)

• Transport the 150 HP Vertical Hollow Shaft (VHS) motor to a reputable local motor rebuild shop.

• Perform a Megger test, clean, bake, and perform Vacuum Pressure Impregnation (VPI) or re-varnish the stator windings.

• Replace upper thrust bearings (must be rated for the extreme down-thrust of 560' of shaft and 1050 GPM hydraulic load) and lower guide bearings.

• Sandblast and epoxy-coat the interior of the discharge head (NSF 61). Replace stuffing box packing/mechanical seal and shaft sleeve.

🔧🔧 Task 4: Sub-surface Equipment Overhaul (560' Setting)

• Column Pipe: Perform ultrasonic wall-thickness tests on all 560 feet of column pipe. Reject and replace any sections showing greater than 15% wall degradation.

• Line Shafting: Check all line shafts on a lathe for straightness (critical for a 560' shaft to prevent vibration). Replace all line shaft bearings/sleeves.

• Bowl Assembly: Completely rebuild the bowl assembly. Replace impellers, wear rings, and pump shafts to restore the OEM factory pump curve capable of delivering 1050 GPM at 580 ft TDH. Coat bowls with friction-reducing epoxy.

🕳🕳 Task 5: 18" Wellbore Rehabilitation

• Pre-Rehab Camera Survey: Conduct a color video survey of the 18" casing down to the total drilled depth (well past the 560' pump setting).

• Cleanout & Sump Bailing: Bail or airlift accumulated sand/debris from the bottom of the well.

• Rehabilitation: Mechanically brush the well screens. Apply customized chemical treatments (acidizing and/or chlorination) based on the camera survey findings to restore specific capacity.

• Post-Rehab Camera Survey: Conduct a final video survey to verify casing integrity and screen cleanliness.

🚀🚀 Task 6: Reinstallation, Calibration, and Commissioning

6.1 Plumbness and Mechanical Alignment

• Discharge Head Leveling: The Contractor shall ensure the pump discharge head is installed perfectly plumb and level over the well casing. Shimming shall be done with machined stainless-steel plates; the use of wedges or temporary spacers is strictly prohibited.

• Motor Shaft Runout: Prior to coupling the motor to the top line shaft, the Contractor shall use a dial indicator to verify the motor shaft runout. Maximum allowable runout at the motor coupling shall not exceed 0.002 inches.

6.2 Lateral Adjustment and Shaft Elongation (Stretch)

• Engineering Calculation: Due to the 560-foot pump setting and the hydraulic down-thrust generated by pumping 1050 GPM at 580 feet TDH, the Contractor must calculate the exact line-shaft elongation (stretch).

• Impeller Clearance: The adjusting nut on the 150 HP Vertical Hollow Shaft (VHS) motor shall be set to lift the impellers off the bowl seats, compensating for the calculated shaft stretch plus the OEM-recommended running clearance.

The Contractor shall document this calculation and the final nut adjustment (measured in turns/fractions of an inch) in the final commissioning report.

6.3 Dynamic Vibration Testing & Tolerances

• Baseline Measurement: Upon startup and stabilization at the design duty point (1050 GPM), the Contractor shall perform a certified vibration analysis using a calibrated vibration meter.

• Test Points: Readings shall be taken at the top motor bearing housing in three independent axes: Horizontal (Parallel to discharge), Horizontal (Perpendicular to discharge), and Vertical (Axial).

• Acceptance Criteria: Vibration levels shall not exceed the maximum allowable limits set forth by the Hydraulic Institute (HI 9.6.4) and AWWA E101 for a 150 HP vertical turbine pump. The overall unfiltered vibration must strictly adhere to the following limits:

Measurement Axis Maximum Allowable Vibration (Peak Velocity)

Condition / Standard

Horizontal (Parallel) 0.15 inches/sec (3.8 mm/sec) HI 9.6.4 / AWWA E101

Horizontal (Perpendicular)

0.15 inches/sec (3.8 mm/sec) HI 9.6.4 / AWWA E101

Vertical (Axial) 0.10 inches/sec (2.5 mm/sec) HI 9.6.4 / AWWA E101

6.4 Corrective Action for Out-of-Tolerance Performance

• If vibration readings exceed the maximum allowable limits, or if motor amperage indicates phase imbalance/mechanical binding, the Contractor shall immediately shut down the pump.

• The Contractor shall diagnose and correct the root cause (e.g., bent line shaft, improper lateral adjustment, or baseplate misalignment) at no additional cost to the Government. The system will not be accepted until dynamic vibration testing falls within the specified tolerances.

• Reinstall the overhauled system.

• Shaft Elongation Calibration: The Contractor must calculate the shaft stretch

(elongation) caused by the hydraulic weight of pumping 1050 GPM from 560 feet. The top adjusting nut must be set with precise lateral clearance to ensure the impellers do not drag on the bowls during operation.

• Disinfection: Chlorinate the well per AWWA C654.

• Testing: Conduct a step-drawdown test to verify the pump meets the 1050 GPM /

580' TDH performance requirement. Monitor 150 HP motor amperage and vibration at the discharge head.

4.0 DELIVERABLES AND QUALITY ASSURANCE

Deliverable Description Timeline

DEL-01 Rigging/Critical Lift Plan 10 days prior to mobilization

DEL-02 150 HP Motor Overhaul & Megger Report 5 business days prior to reinstallation

DEL-03 Pre/Post 18" Casing Video Surveys 5 days after survey completion

DEL-04 Certified Pump Curve & Step-Drawdown Results Step-Rate Aquifer Test Forms Constant-Rate Aquifer Test Form As-built" diagram of the installation, showing pump setting depth, water level, and all component details.

Results from all field tests, including the step-drawdown test and water quality analysis report

3 days after commissioning

DEL-05 Total Coliform / E. coli Lab Results Prior to system tie-in

Because of the depth (560 feet) and high horsepower, bearing failure due to improper shaft alignment or incorrect lateral adjustment is the highest risk during re-commissioning.

END OF SOW

4.0 DELIVERABLES AND QUALITY ASSURANCE