A.02 Attachemnt 1 SOW Thrust Bearing Oil Cooler Retubing Updated.pdf

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

Spare Main Unit Thrust Bearing At John Day Dam

This will be a Firm Fixed Price Supply Contract. TWO (2) sets of coolers (4 heat exchangers total), is to be refurbished by replacing the finned tubing under this contract.

This specification is intended to define materials and services required to rehabilitate Two sets of finned heat exchangers use to cool thrust-bearing oil in hydroelectric General Electric turbine generators. Fresh river water flows 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 is constructed of a frame supporting 24 finned tubes with a supply /discharge manifold on one end and a return header on the other. There are 4 heat exchangers total in the two sets. The normal maximum working pressure is 50psi but will vary with upstream dam head level. and the water temperature ranges from 40-74 degrees with a flow of 170 gpm to 220 gpm as head varies.

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

Manual will be submitted to the Government for approval. As built drawings will be provided with the coolers and placed in the O&M manual when delivered with 3 paper copies and in digital format.

The sketch provided is not a official drawing and is For Information Only . It is titled "Thrust Bearing Oil Cooler Tubes" . The contract will control the specifications.

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 and sealing surfaces resurfaced to flat for sealing.

The tubes are to be rolled.

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 and shall be extruded. The fin outside diameter shall be 1.875 to

2.01”. Fin thickness shall be a minimum of 0.011 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.

part of the bid.

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

Manifolds

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 approved by the government. The gaskets will be installed using Permatex #2 sealant. Gasket material shall be trimmed flush with the periphery of the head and tube sheet if needed.

Hardware

All damaged hardware shall be replaced with like materials. If replaced, bolts or cap screws shall meet SAE J429 Grade 8, with matching washers. Any lock washers used shall be wedge self-locking type such as nordlock, style not classical split washers. Replacement hardware should be plated to resist corrosion. Any deviations must be approved by the government.

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

Twelve tube plugs of proper size, material and taper will be provided to enable 6 tubes to be plugged.

Cleanliness

The coolers will be delivered 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 one hour. Written documentation of the test shall be provided. At the discretion of the Government, a

Government representative may inspect both the on-going work or the pressure testing of the coolers. A certificate of Hydro testing will be provided and mill certificates for the tubes.

Packaging and Shipping

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

Powerhouse east of Rufus, OR. 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 not including shipping crate. The crates may not be stacked. The contractor shall pack the completed coolers for shipment in Contractor constructed new wooden crates designed for long term protected store with future reuse designed in. The crates shall insure adequate protection from damage in transit and the contractor shall be responsible for and make good any or all damage to either coolers or shipping crate that may occur prior to acceptance by the government. As the specified delivery point at John Day Powerhouse.

All shipments are FOB Destination at the dam powerhouse door. 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).