Sunday 1 March 2015

SPECIFICATION FOR FORCED DRAFT AIR-COOLED HEAT EXCHANGERS FOR COOLING WATER SERVICE


1.    GENERAL DESCRIPTION:

Each air-cooled heat exchanger shall be of the forced draft, horizontal (vertical airflow) type or vertical (horizontal airflow), as manufactured by Ecodyne Heat Exchangers located in Houston, Texas.  Each exchanger shall consist of independent horizontal or vertical finned tube bundles, self supporting structural steel frame, plenum chamber, fan ring, fan, removable fan guard, fan bearing assembly, electric motor, motor support, adjustable V-belt drive and removable guard, and a high point expansion tank with atmospheric vent and sight glass.

2.    THERMAL PERFORMANCE & MECHANICAL REQUIREMENTS:

Each exchanger shall be capable of providing the following thermal performance and meet the specified mechanical design values:

Per Ecodyne Model No. 8W-10L-1F7 ACHE’s {part # 08207-001} (4 units)

Detail Description:
1.    Existing Radiators at Planters Pumping Station, cooling the existing Waukesha Engines (Model #: L5792 DSU, Serial # 353587, Specification # G41335), and Philadelphia Gear units (Order No. 452161, Ratio 4.44:1, 775 HP Rating, S/N 106325). 
2.    There are existing four (4) radiators at Planters Pumping Station that need to be replaced.
3.    The existing positions of radiators and their inlet and outlet pipes of unit numbers 1 & 2 are mirror images of units 3 & 4.
4.    The new radiators shall have the same heat rejection capacity as the existing ones, be designed for ambient temperature of 950F that will be experienced in operation, fit on the same foot print, and shall be similar to the Ecodyne Heat Exchangers (Model Number 8W-10L-1F7, Part Number 08207-001), or approved equal. (See attached drawing showing the relevant dimensions).
5.    Each new radiator shall be stamped with its unit number corresponding to its engine number; a field verification by Manufacturer Representative is recommended for new radiators’ positions and their inlet & outlet pipes configuration for the engines and the gear boxes.
6.    The time of fabrication and delivery of units from the date of Notice to Proceed shall be less than 8 months.  Liquidated damages of $200.00 per day will be assessed for each day that expires after 8 months from the date of the Notice to Proceed until all four units are delivered.
7.    The units shall be delivered to the Planters Pump Station, 268 Bypass Road, Belle Chasse, Louisiana 70037.
8.    The cost shall include the fabrication, transportation and delivery to Planters Pump Station.  Jefferson Parish forces will unload the units.
9.     Terms of progressive payments (If required).   The initial 50 percent will be made upon formal purchase order; and the final 50 percent payment will be made after accepting the delivery and inspection by the parish personnel. 


3.    MATERIALS AND CONSTRUCTION:

3.1    Finned Tube Bundle:

3.1.1    Tubes:
The tubes will be welded carbon steel. The tubes shall be roller expanded into the header box tubesheets. The unfinned portion of the tubes, between the fin-side of the tubesheet and the first fin, shall not exceed the thickness of one (1) tubesheet. The exposed unfinned portion of the tubes shall be coated with a minimum of 3 mils of epoxy to prevent corrosion.

3.1.2    Fins:
The fins shall be aluminum, L-footed, spirally wrapped type. The fin count shall in no case exceed 11 per inch. The fin ends shall be stapled to prevent loosening.  In salt air environments, the fins should be of marine grade aluminum or be coated with an epoxy to prevent corrosion.

3.1.3    Header Boxes: (Engine Cool)
The header boxes shall be plug type, fabricated from carbon steel. The header boxes shall be complete with flanged process connections. In addition to the flanged process connections, each header box shall be complete with 1"-3000# FNPT vent and drain connections (with pipe plugs). At least one (1) header box per tube bundle shall be free to "float" to accommodate any thermal expansion or contraction of the finned tubes. The exterior of the completed header boxes shall be SSPC-SP6- prepared and painted with Ecodyne’s standard paint system.

    Header Boxes: (Gear Oil)
The header boxes shall be fabricated from carbon steel. The header boxes shall be complete with process connections. In addition to the process connections, each header box shall be complete with 1"-3000# FNPT vent and drain connections (with pipe plugs). At least one (1) header box per tube bundle shall be free to "float" to accommodate any thermal expansion or contraction of the finned tubes. The exterior of the completed header boxes shall be SSPC-SP6- prepared and painted with Ecodyne’s standard paint system.

3.1.4    Bundle Frame:
Tube supports fabricated from A-36 structural steel shall be bolted to the side frames above and below the finned tube bundle assembly. The spacing of the tube supports shall not exceed six (6) feet. To assure maximum airflow across the finned tubes, heavy gauge galvanized sheet steel air seals shall be installed both at the sides and ends of the tube bundle assembly if gaps exist which would negatively impact performance. Four (4) carbon steel plate lifting lugs shall be welded to the side frames for use in mounting and dismounting the tube bundle assemblies to the support structures. Each entire tube bundle framework assembly shall be hot dip galvanized per ASTM A-123 after fabrication.



3.1.5    Fin Guard:
If required, each tube bundle shall be complete with a removable guard to protect the finned tubes from damage due to falling debris. The guards will be fabricated from 1-1/2” expanded metal welded into a structural angle framework. The guards will be hot dip galvanized per ASTM A-123 after fabrication.

3.2    Support Structure:
Each tube bundle assembly shall be mounted on a self-supporting carbon steel structure. All structural members shall be continuous welded for corrosion resistance. The plenum chambers shall be fabricated from a minimum of 11 gauge sheet steel for the side panels, end panels and the fan decks. These panels shall be bolted to A-36 wide flange beam columns. The fan drive mounts shall be fabricated from A-36 structural channel and shall also be bolted to the beam columns. Each of the columns shall be braced with structural angle "knee" braces to accommodate the specified loading. Each column shall include an oversized carbon steel base plate with holes for anchoring each exchanger. Lifting provisions for both the support structures and the completely assembled exchangers shall be provided. All of the carbon steel material for the support structures shall be hot dip galvanized per ASTM A-123 after fabrication.

3.3    Fans and Drives:

The forced draft fan(s) for each exchanger shall be of the manually adjustable pitch type with airfoil shaped blades fabricated from aluminum. The fan(s) shall be mounted on housed bearing and shaft assemblies via split taper bushings. The fan bearings will utilize tapered roller bearing inserts. The fan(s) shall be “V” belt driven by a 20 HP, 1800 rpm, 3 phase, 60 hertz, 460 volt, totally enclosed, fan cooled, severe duty, electric motor(s). The motor(s) shall include class F insulation, Class B temperature rise and a 1.15 service factor at 40°C. Each fan will be protected by an OSHA compliant, removable, guard. Each belt drive assembly shall be protected by an OSHA compliant, removable, guard. Remote lubrication of the fan bearings will be achieved with tubing routed from the fan bearings to the perimeter of the exchanger. All electrical devices will be suitable for a Class 1, Group D, Div. II area.

4.    FABRICATION:

All materials shall be new and comply with an ASME and/or ASTM specification.

    All welding materials shall comply with ASME specifications.

All pressure retaining welds shall be performed in accordance with ASME procedures and by ASME qualified welders, regardless of exchanger stamping requirements.

All structural welds shall be in accordance with AWS D1.1 and by AWS or ASME qualified welders.

5.    TESTING:

Each tube bundle shall be pressure tested in accordance with the requirements of the ASME Section VIII, Division 1 code. The pressure test shall be conducted with a rust inhibited water solution for a minimum of 30 minutes. After pressure testing, each tube bundle shall be drained, dried and sealed and charged with 3-5 PSIG of nitrogen.

Each exchanger shall be factory run tested prior to shipment. The results of airflow, noise and vibration tests will be reviewed and documented for compliance with the design requirements.

6.    PREPARATION FOR SHIPMENT:

    Each exchanger shall be completely factory assembled prior to shipment.

            The tube bundles shall be charged with 3-5 PSIG of nitrogen and sealed prior to
            shipment to minimize the entrance of contaminants during shipment and storage.

7.        PERFORMANCE AND PAYMENT BONDS

In order to insure the faithful performance of each and every condition, stipulation, and requirement of the contract and to indemnify and save harmless the Owner from any and all damages, either directly or indirectly, arising out of any failure to perform same, the successful bidder to whom the contract is awarded shall furnish a surety Bond in an amount at least equal to one hundred percent (100%) of the contract price, unless otherwise specified.  The successful bidder to whom the contract is awarded shall also furnish a labor and materials payment Bond in an amount at least equal to one hundred percent (100%) of the Contract Price, unless otherwise specified.  The Contract shall not be in force or binding upon the Owner until such satisfactory Bonds have been provided.  The Sureties shall be selected by the Contractor, subject to the approval of the Owner, and the cost of the Bonds shall be paid for by the Contractor, unless otherwise stipulated in the Supplementary Provisions.

Any security Bond written for a Jefferson Parish public works project or any other Jefferson Parish Contract requiring a bond shall be written by a surety or insurance company currently on the U.S. Department of Treasury Financial Management Service list of approved bonding companies which is published annually in the Federal Register, or by a Louisiana domiciled insurance company with at least an A rating in the latest printing of the A.M. Best’s Key Rating Guide to write individual Bonds up to ten percent of policyholder’s surplus as shown in the A.M. Best’s Key Rating Guide or by a security company that complies with the requirements of LSA-.R.S.38:2219

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