Statement of Work.pdf

Replace Chilled Water Coils at AHU-1 Cereal Crops Research Unit (CCRU) USDA-ARS, Madison, WI

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Scope of Work Description

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Scope of Work Description:

1. Project Location: USDA-ARS-CCRU

502 Walnut Street Madison, WI 52726

2. Point of Contact at Location: David Lamar

(608)-346-0736 david.lamar@usda.gov

3. MWA EPM: Wayne Myers

(309)-681-6124 wayne.myers@usda.gov

4. The project shall include a Base Bid, Bid Option 01, Bid Option 02, and Bid Option

03.

Base Bid: Provide replacement of chilled water coils at AHU-1 of the CCRU facility along with associated piping modifications as described below and in accordance with this Statement of Work.

Bid Option 01: Provide piping / ductwork installation to vent drained coiling coils as described below and in accordance with this Statement of Work.

Bid Option 02: Provide replacement of control valve assembly, control valve bypass piping, calibrated balancing valve, pressure gauges, thermometers, and shutoff valves that are located in 6” chilled water piping header to AHU-1 as described below and in accordance with this Statement of Work.

5. Interested parties are strongly encouraged to visit the site of the proposed work and review the existing conditions relating to construction and labor, to be fully informed as to the facilities involved, and the difficulties and restrictions that may affect the performance of the Contract. Failure to visit the site will not disqualify those submitting a proposal. However, change order requests for items that could have been reasonably ascertainable from a site visit (and included in a proposal) will be reviewed by the CO and evaluated accordingly.

6. Scans of original construction drawings of the Cereal Crops Lab (dated February

2004) are provided in the project’s solicitation package. The Contractor shall use the existing drawings as reference / resource in developing their bid / proposal. The Contractor shall confirm all existing conditions, dimensions, etc. prior to proceeding with any project activities.

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7. The scope of the project shall be, generally, replacing chilled water coils with new along with associated modifications to provide properly operating mechanical equipment as originally intended. The coil replacement and associated modifications shall be in accordance with this Statement of Work and the FAR Solicitation and Contract clauses that are identified in the complete Solicitation package. This Statement of Work (SOW) shall consist of this “Scope of Work Description”, Project Specifications, Attachments, General Notes and Requirements, Photographs, and Existing Drawings.

A. The replacement / repairs shall be performed in a neat, workmanlike manner to provide code-compliant, complete, properly functioning installation.

B. Contractor shall be responsible for all project waste including hauling away, directing waste to recycle, and legally disposing of remaining waste. See Project Specifications for additional information on requirements for directing waste to recycle.

C. The replacement of the chilled water coils and associated piping system modifications shall be sequenced and scheduled to minimize the time period of air handler AHU-1 shutdown and its impact to the facility. For bidding purposes, the Contractor shall assume that coil replacement and associated piping system modifications will occur over a weekend, starting at 3:00 pm on Friday and with restoration of a functional air handler completed by 5:00 pm on Sunday (i.e. air handler and cooling coils shall be functional and producing cooling – final trim out items such restoration of pipe insulation, balancing, etc. can occur during weekdays during normal working hours).

Base Bid work and Bid Option 02 work may occur on separate weekends as needed to comply with these time constraints.

Contractor shall assume Bid Option 01 work will be performed during normal working hours.

D. Contractor shall provide all materials and components needed for the indicated replacement / repairs. All materials and components furnished for the repairs shall be 100% compatible with the existing air handler. Contractor shall provide product data sheets in their proposal on the materials that will be furnished for the indicated repairs. See Note 16 for additional information. Provide information on:

Chilled water coil(s) – Provide product data sheets Piping materials – Provide product data sheets Piping components / accessories (valves, gauges, thermometers, etc.) –

Provide product data sheets Pipe insulation – Provide product data sheets

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8. Existing Conditions:

Existing air handler AHU-1 has two chilled water coils (upper and lower). Mechanical drawings dated 2004 from original building construction indicate the following on the chilled water coil(s) (see “Existing Drawings” for additional information – Air Handler Schedule is shown on M-810):

Maximum face velocity: 450 ft / min Entering air: 87.4 dB °F; 73.4 wB °F Leaving air: 52.0 dB °F; 51.3 wB °F Maximum SP Loss: 5 in H2O Waterside Flow: 420 gallons / min Maximum Pressure Drop: 10 ft H2O Entering Water: 42° F Leaving Water: 56° F Minimum Sensible Cooling Capacity: 1630 MBTUH Minimum Total Cooling Capacity: 2950 MBTUH

Approximate dimensions of each existing coil are 133” W x 53” H x 12” D.

Contractor shall confirm dimensions of each coil prior to ordering / purchasing of new coils.

Chilled water is supplied to the CCRU facility from University of Wisconsin. For bidding purposes, Contractors shall assume that the chilled water does not contain glycol.

Existing chilled water piping system to AHU-1 consists of 6” chilled water supply and return lines routed to the air handler with 3” branch runs /connections to each coil. See “Existing Drawings” for additional information and reference “Detail 1 – Multiple Coil Piping Detail”. The piping system includes, but not limited to, the following piping components and accessories:

Shut off valves on main 6” supply and return lines to AHU-1.

Calibrated balancing valve with flow sensors on main 6” return line to AHU-

1.

Pressure gauges and temperature thermometers on main 6” supply and return lines to AHU-1.

“Y” strainer with blowdown valve and hose bibb on main 6” supply line to

AHU-1.

Control valve assembly on main 6” return line to AHU-1. Control valve assembly shall consist of automatic two-way control valve with shut-off valves; shut-off valves are provided on both inlet and outlet sides of control valve.

Bypass assembly around control valve assembly with globe valve. Bypass is full size of the control valve.

Shut-off valve at branch supply line to each coil.

Shut-off valve at branch return line to each coil.

Balancing valve at branch return line to each coil.

Pressure gauge and temperature thermometer on each branch supply and return line to each coil.

Automatic air vent on each coil.

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Drain assembly at each coil, connected to branch line. Drain assembly consists of 3/4” pipe with shut-off valve and hose bibb.

9. Base Bid: The scope of Base Bid shall include, but not limited to:

Contractor shall remove two (2) chilled water coils in their entirety and replace with new. See “Requirements for Chilled Water Coils” below for additional information.

Contractor shall disconnect and remove existing chiller water supply and return lines, along with associated pipe insulation to allow removal of coils.

Remove existing 3” branch supply and return lines to each coil in their entirety. Remove existing 6” main supply and return lines to AHU-1 back to ceiling space of Mechanical Room (remove vertical risers of piping run).

Contractor shall provide chilled water connection (supply and return) to each new coil including the furnishing and installation of new chilled water piping, associated valves, piping components, and piping accessories. See “Requirements for Chilled Water Piping Installations” for additional information. Intercept and extend 6” piping to restore originally intended installation. Provide connections to coils with 3” piping. The renovated piping system shall include providing the following new components / accessories in the installation:

o Shut-off valve at branch supply line to each coil.

o Shut-off valve at branch return line to each coil.

o Balancing valve at branch return line to each coil.

o Pressure gauge and temperature thermometer on each branch supply and return line to each coil.

o Automatic air vent on each coil.

o 2” stub-out at one of branch lines to each coil. Each stub-out shall be nominal 12” in length and shall be located downstream of shut-off valve at coil. Stub-out installation shall include shut-off valve and shall be capped. New shut-off valve shall be full port type and equipped with quarter turn handles, PTFE seats and seals, chrome plated brass ball, and blowout proof valve stems. Stub-out shall be in branch line that does not have drain assembly. (Stub-out shall be used in venting of coil as described in Bid Option 01).

o Drain assembly at each coil, connected to allow draining of coil. Drain assembly shall consist of 3/4” pipe with shut-off valve and hose bibb.

Removal and replacement of freeze-stat at AHU-1 that protects the chilled water coils. New freeze-stat shall be:

o Compatible with facility’s building control system.

o Serpentine, capillary type; providing full coverage across the new coils

(additional elements shall be provided as needed for complete coverage across the new coils).

o Manual reset type with auxiliary contacts. Contact arrangement shall be selected to maintain existing interlocks with AHU-1 control and building control system. A freezing condition at any 18” increment along the sensing element shall activate the auxiliary contacts.

(Existing freeze-stat is interlocked with AHU-1 control through a normally closed contact and is providing digital input to facility’s building control system through a normally open contact.)

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Contractor shall modify and restore AHU casing / enclosure as needed for coil replacement.

Contractor shall fill and vent the new coils and associated piping to provide properly filled system.

Contractor shall furnish and install new pipe insulation to restore a fully insulated chilled piping system to AHU-1. Installation of new pipe insulation system shall include restoration of pipe insulation disturbed by the Contractor in performance of the project’s scope for Base Bid and restoration of pipe insulation that has been removed by the Owner. See “Requirements for Pipe Insulation Systems” below for additional information.

Contractor shall engage a testing, adjusting, and balancing (TAB) firm for this project. TAB firm shall be certified by either AABC or NEBB and shall perform TAB services for this project. See “Requirements for Testing, Adjusting, and Balancing” below for additional information.

10. Bid Option 01: The scope of Bid Option 01 shall be piping installation to allow air

“cold weather” venting of coils. The installation shall include, but not limited to:

Contractor shall provide new 4” rigid PVC air duct from existing air supply line in Mechanical Room 157 to each new 2” stub out at branch line to each coil.

(See Note 9 – Base Bid for more information on 2” stub-out).

Contractor shall all fittings and materials needed and make connection to existing 6” diameter supply air duct near north wall of Mechanical Room and direct a portion of the air flow into 4” PVC duct. Provide volume air damper / valve at point of connection to 6” duct. See “Existing Drawings – Sheet M- 210” for additional information.

Contractor shall provide 4” rigid PVC air duct to vicinity of AHU-1 chilled water coils. Route 4” air duct in ceiling space of mechanical space in neat, workmanlike manner. For bidding purposes, assume 40 feet of 4” PVC duct along with associated fittings and components.

At vicinity of chilled water coils, provide 2” rigid branch duct to each 2” stub-out. Provide all fittings and components needed to transition to 2” duct.

Provide volume air damper at each 2” duct run to balance air flow through coils. For bidding purposes, assume 20 feet of 2” PVC duct for each branch run along with associated fittings and components.

Contractor shall provide all fittings and materials needed and provide final connection to 2” stub-outs at supply line to each coil.

11. Bid Option 02: The scope of Bid Option 02 shall include, but not limited to: (see

“Requirements for Chilled Water Piping Installations” below for additional information) Contractor shall remove existing shut-off valves on existing 6” main supply and return lines routed to AHU-1 and replace with new.

Contractor shall remove existing balancing valve on main 6” return line to

AHU-1 and replace with new.

Contractor shall remove existing pressure gauges and temperature thermometers on main 6” supply and return lines to AHU-1 and replace with new.

Contractor shall maintain and re-use existing “Y” strainer with blowdown valve and hose bibb on main 6” supply line to AHU-1.

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Contractor shall remove existing control valve assembly on main 6” return line to AHU-1 and replace with new. Control valve assembly shall consist of automatic two-way control valve with shut-off valves on both inlet and outlet sides of control valve. Removal and replacement shall include disconnecting / reconnected electrical interlock with facility’s building control system.

Contractor shall remove existing bypass assembly around control valve assembly and replace with new. Bypass shall consist of piping with shut-off valve, size of bypass assembly shall match the full size of the control valve

Contractor shall fill and vent the new coils and associated piping to provide properly filled system.

Contractor shall furnish and install new pipe insulation to restore pipe insulation disturbed by the Contractor in performance of the project’s scope for Bid Option 02. See “Requirements for Pipe Insulation Systems” below for additional information.

12. After project award, the Contractor shall inspect / confirm all existing conditions and dimensions prior to proceeding with any project activities and identify all existing conditions that may impact the work and alert the CO and EPM immediately if conditions are discovered that differ from the SOW. Contractor shall point out discrepancies between work identified in this SOW and actual field-verified conditions--if they exist, prior to performing work. Items not identified in SOW may be treated as unforeseen conditions and priced in accordance with standard FAR contract clauses. Coordinate with location for laydown and staging areas.

13. Period of performance shall be as indicated in the Contract Documents and begins after Notice to Proceed is issued by CO.

14. Basis-of-design products are indicated in this SOW to convey a specified standard of quality and salient characteristics desired but are not to be considered a single-source specification. Contractor-proposed equals will be considered.

The Contractor must compare and validate that quality and salient characteristics are equal and approve the proposed equal products prior to submission for Government review and approval. Additional work required to incorporate Contractor-proposed equals shall be at the Contractor’s expense.

Owner will review all Contractor-proposed equal equipment, materials, manufacturers, or installation. It shall be the Contractor’s burden to furnish all documentation and / or samples to show equality with specified items.

Owner’s decision on equality is final.

15. In their proposal, Contractor shall include product data sheets on the chilled water coils, chilled water piping, shut-off valves, control valve assembly, balancing valves, and associated components to be furnished in the indicated repairs.

Product data sheets shall indicate and shall be clearly marked to identify the specific model, size, dimensions, capacities, and performance characteristics of the material / component to be furnished.

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16. The Contractor shall furnish all labor, materials, equipment, supplies, transportation, utilities, supervision, *safety equipment, and incidentals for all elements of the work to provide a complete and properly functioning installation in accordance with this Statement of Work. The installation shall be ready for use by Final Completion date.

* Note: Contractor is solely responsible for safety measures and conformance to applicable requirements in accordance with FAR clauses referenced in Solicitation package.

Contractor shall provide all means and methods to protect the facility and its installations from all project activities, including protecting the facility from environmental elements as the improvements are completed.

17. Contractor shall coordinate all work activities with the Owner prior to beginning any work. All work shall be scheduled in a manner such that ongoing research is not jeopardized, and facility’s ongoing day-to day operations are not affected negatively, including air quality.

Project shall be left clean at the end of each workday.

Contractor shall coordinate access to all areas with the designated USDA staff.

Contractor shall verify all parking, security, and health requirements with the

USDA staff.

Coordinate with location for laydown and staging areas.

18. Applicable Codes and Standards:

Current State of Wisconsin Building Codes.

All current Madison, WI local codes.

Most recent International Building Codes

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Requirements for Chilled Water Coils:

1. New chilled water coils shall be for direct replacement and shall match existing coils in type, physical size, and capacity.

2. New coils shall be constructed of copper tubes with aluminum fins mechanically bonded to the tubes and with galvanized steel end casings. Fin design shall be sine wave rippled, 10 fins per inch. Coils shall have row design and number of rows to provide the performance characteristics indicated. Minimum tube thickness shall be 0.035”.

Coils shall be certified in accordance with ASHRAE Standard 410 and shall be hydrogen leak tested.

Coils shall be mechanically supported above drain pan to allow drain pan cleaning and coil removal.

Coil connections shall be labeled and extend beyond air handler unit casing.

Coil headers and return bends shall be fully contained within the end casing(s) of the coil.

3. New cooling coil(s) shall be installed in accordance with the written instructions and recommendations of the coil manufacturer. Additionally, the installation shall be in accordance with the recommendations of applicable ASHRAE standards and requirements of latest edition of ICC international codes.

Installation of the coil shall include furnishing and installation of metal fabrications to completely seal coils to the air handler casing to prevent leakage of air around cooling coil(s).

4. Existing drip / drain pan(s) may be re-used. Locate and arrange drain pans for proper capture and draining of condensate. Provide piping to route captured condensate to drain. Installation shall be as indicated in Detail 7 on Sheet M-611 of “Existing Drawings”.

Requirements for Chilled Water Piping Installations:

1. New and renovated piping installations of chilled water supply (CWS) and chilled water return (CWR) lines shall meet or exceed the requirements of the latest edition of ICC International Plumbing / Mechanical Codes.

2. New piping for CWS and CWR lines shall be Schedule 40 steel pipe with wrought-cast or forged-steel flanges and flange fittings and with welded and flanged joints. Steel pipe shall conform to ASTM A 53/A 53M. Flange and flange fittings shall conform to ASME B16.5 and shall include bolts, nuts, and gaskets.

Piping shall be routed parallel to and at right angles to structural elements in neat, level / plumb, workmanlike manner. Contractor shall provide all mounting hardware for proper support of piping system.

3. Pipe hangers shall be provided at change of directions and at maximum spacing of 6 feet for CWS and CWR piping. In addition, pipe hangers shall be located within 12” of joints at each change of direction and shall be located within 18” of joints for straight runs. Pipe hangers and supports shall include provisions such that piping system is completely insulated through hanger / support.

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4. New thermometers shall be mercury-free, liquid-in-glass type complying with ASTME.1; shall have scale range of 1-120 deg F with 2-degreee scale divisions;

shall have adjustable joint; shall have blue reading, organic-filled tube with magnifying lens; shall have white aluminum scale with black markings and stem of length to suit installation; Weksler Model A935AF2**AF2-AL series or approved equal. Contractor shall provide compatible stainless-steel thermometer well. Installation of new thermometers and associated wells shall be in accordance with manufacturer’s written instructions and recommendations.

5. New pressure gauges shall be phosphor-bronze bourdon-tube type with bottom connect; dry tube type complying with ASME B40.1; shall have stainless-steel case with 4-1/2” diameter lens; shall have white-coated aluminum scale with black markings; shall have accuracy of ± 1% of full scale; and shall be provided with stainless-steel needle type valve; Weksler Model EA14E series or approved equal. Installation of new pressure gauges shall be in accordance with manufacturer’s written instructions and recommendations.

6. New shut-off valves shall be butterfly type unless noted otherwise. New butterfly valves shall be 125 CWP, iron, single-flange type complying with MSS SP-67, Type 1; shall be lug type with EPDM seat, stainless-steel disc and stainless-steel stem; shall have throttling handles with a minimum of seven locking positions;

and shall extended neck to accommodate insulation thickness. Size of shut-off valve shall match size of piping where valve is installed. Installation shall be in accordance with manufacturer’s written instructions and recommendations.

7. New balancing valves shall be calibrated type so that flow can be determined when the temperature and pressure across valve is known Valves shall be constructed for working pressure of the application; shall have provisions for connecting a portable differential pressure meter; shall have built-in check valves for meter connections; shall have a integral pointer to register degree of valve opening; shall be constructed with internal seals to prevent leakage around rotating element; shall be Bell & Gossett or approved equal. Size of balancing valve shall match size of piping where valve is installed. Installation shall be in accordance with manufacturer’s written instructions and recommendations.

8. New control valves shall be 100% compatible with the facility’s building control system; shall match existing control valve in size and performance characteristics; and shall be selected based on medium to be controlled, maximum inlet temperature and pressure at the valve, the pressure differential that will exist across the valve under maximum load demand, the maximum capacity the valve must deliver, the maximum line pressure differential the valve actuator must close against, for actual expected conditions, and with actual pipe sizes where the valve will be installed; Siemens or approved equal. The new control valve shall be normally closed, two-way, electrically actuated (electronic) type that is powered from 24VAC supply, capable of operation from 0-10V or 4- 20mA control signal (DIP switch selectable); shall have direct-coupled installation, visual and electronic stroke indication, manual override, spring return

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to fail-safe position, automatic stroke calibration, and maintenance free operation. Installation of the new control valve shall be in accordance with the manufacturer’s written instructions and recommendations. The new control valve shall provide proportional control of the valve across the entire control signal range.

9. New automatic air vents shall be ball-float type with brass/bronze or brass bodies, corrosion-resistant steel float, linkage, and removable seat. End connections of vents shall not be less than 1/8” threaded connection.

10. New and renovated CWS and CWR water piping system(s) shall be completely insulated piping system(s).

11. New and renovated new CWS and CWR piping systems shall be tested for leaks with corrective measures implemented when leaks are identified. Testing shall be performed prior to installing any pipe insulation.

12. New and renovated CWS and CWR piping systems shall be labeled to provide clear indication of use and direction of flow. Labeling shall be applied after pipe insulation has been installed and is complete.

Requirements for Pipe Insulation Systems:

1. Where pipe insulation is specified for a piping system, the new and renovated pipe insulation system shall be complete in every respect and ready for use.

2. Unless noted otherwise; new interior pipe insulation system shall be mineral fiber, Type 1 complying with ASTM C 547, 1.5” thick, performed pipe insulation with vapor barrier and all purpose, reinforced fire-retardant jacket with white surface unless noted otherwise.

Requirements for Testing, Adjusting, and Balancing (TAB)

1. Contractor shall provide TAB services to measure and adjust water flow at chilled water coils of AHU-1. See Photograph 1 for piping arrangement and location of balancing valves serving AHU-1. Adjust balancing valves to provide specified water flow rate to AHU-1 (420 gal/min) with associated control valve in a fully open position and to provide equal flow to each chilled water coil.

After above adjustment; measure and record flow rates of main piping to AHU-1 and flow rates to each chilled water coil with control valve at 10% open, 25% open, 50% open, 75% open, and fully open. Indicate flows recorded in the TAB report.

2. Contractor shall provide TAB services to measure heat-transfer at new cooling coils. Measure and record data on the following with the control valve in a fully open position:

Entering-water and leaving-water temperature.

Water pressure drop.

Dry-bulb temperature of entering and leaving air.

Wet-bulb temperature of entering and leaving air.

Air flow Air pressure drop

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3. All measurements shall be performed with instruments that have been calibrated at least every six months or more frequently if required by instrument manufacturer.

4. Contractor shall submit a TAB report, prepared and certified by the TAB firm, to the Owner indicating all recorded data and presented on forms certified by the TAB firm. Report shall also identify any irregularities and difficulties encountered during measurements.