Attachment 1 - Scope of Work.pdf

SCOPE OF WORK

Repair of 2 Rooftop Condensing Units for Walk-In Freezer, Rm #44, Building #17

GENERAL INFORMATION

1.0 Background and Purpose

The United States Meat Animal Research Center is a facility with many facilities that aid in the production of various research projects and animal husbandry. As part of the effort the 2 rooftop condensing units for the walk-in freezer, rm. #44 in building 17 need to have the suction pipe and the freon replaced.

The condensing units are Larkin as manufactured by Heatcraft Refrigeration Products. The model number is LDVS2201L6D with serial numbers 10102374R and 10102375R. These condensing units are part of a Beacon II split system.

The evaporators for this split system are Larkin model #LHL4710DPA with serial numbers T10L01590 and T10L01591.

CONTRACTOR REQUIREMENTS

2.0 Technical Requirements/Tasks

The tasks shall include the following:

1.

2.

Remove existing freon from each condenser unit. Existing freon is primarily R-507 although there is some R-404a. Evacuate the systems from both sides to .3 mbar. Dye used for detecting leaks is in one of the units.

Replace all existing suction copper pipe from refrigerant evaporators to compressors with new 1-5/8” ACR copper pipe, including all fittings, elbows, cores, and other suction pipe material as required. There is approximately 60’ of suction pipe in one system and approximately 40’ of suction pipe in the other system.

3.

1.

Install all suction pipe insulation from the refrigerant evaporators to refrigerant compressors. Insulation shall be new closed cell black foam self sealing insulation, minimum 1.5” wall thickness. Insulation shall conform to ASTM C534, Grade 1, Type

A weatherproof protective jacket ITW .016” thick aluminum shall be installed for exterior insulation. Provide PVC jacket for suction line piping inside building.

Fiberglass insulation is not acceptable.

a. Install insulation system vapor stops upstream and downstream of valves, refrigeration specialty devices and at equipment connections.

b. Maintain insulation material thickness, insulation system vapor retarder, and insulation system protective jacketing continuity through wall, ceiling, and roof penetrations.

Submittals:

Literature shall be submitted for all material to be supplied prior to ordering.

Demolition:

4. Install freon R-449a in both systems and fill both refrigeration systems to capacity which may be different than the R-507 capacity. Capacity of each system is 61.5 lbs of R-507.

This work shall include pressure testing the systems to 300 psi for 24 hours with nitrogen prior to putting freon into the systems. Follow proper charging procedures. Do not charge liquid into the suction line.

5. The following should also be included:

a. Replacement of thermostatic expansion valves (TXV).

b. Replacement of orifices as needed.

c. Replacement of filter driers with equilibrium of dryness of 50 ppm or lower. Solid core or compacted bead type driers are acceptable.

d. Replacement of other material if needed for compatibility with R-449a.

6. Determine superheat, subcooling and set properly.

7. Set pressure cut-ins and cut-outs if needed.

8. Replace existing POE oil in both condenser units and lubricant filters if present. Provide oil as necessary to fill both refrigeration systems to capacity. Each system is thought to hold a minimum of 1 gallon of oil. It is believed that one system is near this capacity.

The other system is believed to have just enough oil to operate, but it is not believed to be at capacity.

9. All suction piping shall be properly supported.

10. Patch and repair wall/roofing as necessary where pipe is routed through them.

11. Contractor is responsible for verifying all field conditions, sizes of material, and distances prior to purchase of material.

12. Properly label/tag the compressors for R-449a and the lubricant used.

13. All settings of condensing units shall be adjusted for R-449a.

All material removed and not reused shall be removed by the contractor from the site.

Toilets:

Contractor may use Building #17 bathroom facilities if use is not abused. If use becomes an issue, contractor will be expected to provide their own facilities.

Access to Buildings:

Contractor's access to buildings shall be limited to those areas where work is being done.

Material Receiving:

Contractor shall be responsible for receiving and storage of all materials. Material shall not be shipped to owner's warehouse under any condition.

Security:

All contract personnel are required to complete a form to register as being on-site and shall also agree to a written statement of conduct while on the property.

Cleanup:

The Contractor shall keep the premises clean during construction and shall remove all rejected material, rubbish, etc., after completion of work and prior to final inspection.

Project time:

1.0 Deliverable/Schedule/Address:

All of this work shall be accomplished within a three week time period.

Work must begin 10 days after award. Work must be completed in a 3-week time period.

Facility address is listed below:

USMARC

844 Rd 313 Clay Center, NE 68933

4.0 Performance Requirement Measures:

Work must be completed in a 3-week time period.

5.0 Government Point of Contact:

Joe Warrick, Phone: (402)762-4131, joe.warrick@usda.gov