Statement of Work (SOW) Thrust Bearing Oil Cooler Retubing.pdf

Statement of Work

Specifications For Thrust Bearing Oil Cooler Rehabilitation and Re-tubing Of

Spare Main Unit Thrust Bearing For John Day Dam

General

This specification is intended to define materials and services required to rehabilitate finned heat exchangers used to cool thrust-bearing oil in hydroelectric General Electric turbine generators. No original drawings are available. Fresh river water flows at @ 220 gpm through the tubes which are immersed in a bath of ISO 68 DTE Heavy Medium turbine oil. Each cooler set is comprised of two semi-circular halves. Each cooler half, side A and B, is constructed of a frame supporting 24 finned tubes with a supply /discharge manifold on one end and a return header on the other.

Prior to beginning work all material, construction drawings and an Operation and

Maintenance Manuals will be submitted to the Government for approval. The two cooler halves, A and B, will be examined upon receipt and any unusual condition reported to COR.

The government will be notified the inspection has taken place. No work is to be done outside the contract including optional CLINS without the express permission of the

Contracting Officer.

On completion of work, as-built drawings will be provided by the contractor to the

Contracting Officers Representative (COR) and placed in the O&M manual with 3 paper copies and in digital format. Each cooler will have its own serial number and the A and B sides be designated on nameplate.

All tubing, cooling fins, and gaskets must be replaced due to wall thinning and leakage causes by wear and /or corrosion. Leakage in a cooler would result in shutdown of the generator, loss of carbon free electrical production and a major disassembly to access the tub. This unit is a critical spare part and the highest quality is required in manufacture.

Unit is to be disassembled, cleaned, including head interiors, and sealing surfaces resurfaced and/or machined flat for sealing.

The unit is to be inspected after receiving it and any additional findings reported to the

Contracting Officer as soon as possible.

The tubes are to be rolled.

Tube taper plugs of the proper size will be provided to allow six tubes to be plugged, 12 plugs total for each cooler and listed on the packing list for shipping.

Tubing

The replacement tubing shall be made of 90/10 Cu Ni SB111 C70600 with a minimum wall thickness of 0.049” (existing) to a maximum of 0.065”. Tubing OD shall be 1.00 inch. The tubes are two different lengths and radii. There are 12 tubes of each length for each half, 24 tubes on each half; totaling 48 tubes per full thrust bearing oil cooler.

Approximate lengths of the tubing are 17’ 1-3/8 inch inner and 17’ 9 5/8 outer. Approximate radii to tube centerline are 6’ 3” and outer 6’ 6”. The fins shall be finned 7 to 9 fins per inch.

The fins shall be aluminum. The fin outside diameter shall be 1.875 to 2.01”. Fin thickness shall be a minimum of 0.012 to a maximum of 0.016. Damage to the fins such as bending and separation from the tubing may occur when the tubes are inserted into the frame. Not more than 1% noticeable fin damage is allowed in the finished cooler.

Manufacturer’s specification of the proposed finned tubing And a sample shall be submitted as part of the bid.

Tube rolling shall conform to TEMA standards and ASME standards for Heat Exchangers including wall thinning after rolling.

Manifolds And Heads

A new gasket shall be installed on each head. The gasket shall be a semi-rigid non –asbestos type formulated for both oil and water service. New gaskets are stock items that will be provided by the government at the time the coolers are picked up. The gasket will be installed using Permatex #2 sealant. Gasket material shall be trimmed flush with the periphery of the head and tube sheet if needed. Heads will be machined flat if required to allow sealing.

Hardware

All damaged hardware shall be replaced with like materials. Head bolts or cap screws shall be replaced and meet SAE J429 Grade 8, with matching washers. Any lock washers used shall be wedge self-locking type such as nordlock, not classical split washers. Replacement hardware shall be plated to resist corrosion.

Proper anti seize will be applied on threads to prevent galling. A torque table will be supplied and indicated on as built prints and the manual designating torque and lubrication for future assembly.

Nameplates

The original manufactures name plate will be retained. A new plate signifying the retubing with date, contractor’s name, serial number and A side or B side at a minimum will be attached to the head.

Cleanliness

The coolers will be delivered to the government in a clean condition so that no cleaning is needed prior to installation. No metallic particles or other foreign mater shall be visible on the coolers.

Testing

Each complete cooler shall receive a hydrostatic pressure test at 75 PSIG In accordance with

Pressure Vessel Standards. The pressure must hold for a minimum of 1.5 hours. Written documentation of the test shall be provided. At the discretion of the Government, a government representative may inspect both the on-going work and the pressure testing of the coolers.

Head Replacement Option

If upon initial inspection called for above, the heads are beyond repair, the Contracting Officer may authorize the replacement of the heads as an Optional Item.

New heads will be modeled on the existing heads with impingement plate as needed and will meet TEMA standards.

The current steel heads are @35 inches long by 8 inches wide with 52 closely spaced bolt holes with 4 ½ NPT pipe plugs, 2 at the top and 2 at the bottom. Two of the four heads, the supply/discharge manifold head, contain inlet/outlet 2 inch steel piping with 150 pounds flanges. New manifold heads must have the piping and flanges targeted with existing cooler to ensure fit when reinstalled.

If replaced, the old heads will be retained and returned to the project when the coolers are shipped back.

Packaging and Shipping and Optional Crate

The contractor shall be responsible for providing transportation to and from The John Day Dam

Powerhouse east of Rufus, OR. The contractor is the shipper and all shipping documents will be prepared in advance and provided to trucking company and John Day Project (COR). The cooler halves will be picked up in Government-provided shipping crates. Each shipping crate measures approximately 14 feet long by 5.5 feet wide and 4.5 feet high. The weight is approximately

2,200 pounds for one cooler half, two in total for 4,400 pounds. The crates may not be stacked.

The contractor shall pack the completed coolers for shipment in government supplied wooden crates.

If the government furnished crates become damaged or unsuitable for use during transit, the government may authorize the fabrication of a new crate from the contractor, based upon Contracting Officer pre-approval as an Optional Item. If necessary, the new crate will be strongly constructed for long term protected storage with reuse designed in. The crates shall insure adequate protection from damage in transit and the contractor shall be responsible for or make good any or all damage to either coolers or shipping crate that may occur prior to acceptance by the government, should the crate become damaged in transit, beyond the normal wear and tear of scuffs, scratches, etc.

All shipments are FOB Destination. Contractor will pay for all shipping related costs in both directions. Government crane service will load and unload the crates.

John Day is on a 4-day work week and the Warehouse hours are only Monday thru Thursday

0700 -1600 Pacific time. Any other transportation arrangements shall be made well in advance prior to transportation departure and with written approval from the Contracting Officer’s

Representative (COR).

Deliverables

1. Inspection of coolers A&B upon receipt condition report

2. Material, drawings and manual prior to starting retubing

3. Two sets of coolers retubed with new hardware as needed

4. Torque specifications for head fasteners on drawings and manual. Three sets of paper copies of all and one digital PDF copy.

5. New nameplates on heads

6. Hydro test documentation

7. Shipping both ways.

Government Supplied Equipment

Four head gaskets will be shipped with the coolers.

Optional Items CLINS

Head replacement, with old heads returned.

New Crate Constructed

Retube & Refinish 2nd Thrust Bearing Oil Cooler Set