All inquiries, questions, requests for substitution, and/or clarifications:
Must be submitted in writing via the email below according to the directions given in
the Request for Approval of Substitution and in the Instructions to Bidders prior by 12:00
PM, Friday, April 26, 2024.
All questions should be directed to:
By emailing: Trish Creta
Senior Construction Project Manager
City of Durham General Services Department
Phone - (919) 560-4197
trish.creta@durhamnc.gov
Underutilized Business Enterprise (UBE) goals:
The Underutilized Business Enterprise (UBE) goals for this project are MBE 0% and
WBE 0%. Bidders are responsible for filling out the required UBE Construction forms
and including them in their bid package to be considered responsive. Contract completion time for all work on this project is 100 calendar days. SCOPE OF WORK
A. Project Description
B. Replacement of Module 1 compressor
1. Equipment Information
Make: Multistack
Equipment Model #: MS080TC3H2W2AAC-R134A
Serial #: AE 02 066
2. Recover refrigerant 134a from the module and dispose of per EPA
regulations.
3. Furnish all required rigging to hoist compressors from stairwell to equipment
room.
4. Furnish all required rigging to remove old compressor and set new
compressor.
5. Disconnect refrigerant lines and electrical from old compressor and remove.
6. Furnish and install new compressor and reconnect refrigerant lines and
wiring.
7. Leak test the repairs and evacuate system to 500 microns.
8. Perform a 1 hour vacuum decay test. Load 80 lbs. of new refrigerant into the
system.
9. Power up new compressor and commission.
10. Startup module for proper operation and performance.
C. Replacement of Module 4 compressor
1. Equipment Information
Make: Multistack
Equipment Model #: MS080TC3H2W2AAC-R134A
Serial #: AE 02 065
2. Recover refrigerant 134a from the module and dispose of per EPA
regulations.
3. Furnish all required rigging to hoist compressors from stairwell to equipment
room.
4. Furnish all required rigging to remove old compressor and set new
compressor.
5. Disconnect refrigerant lines and electrical from old compressor and remove.
6. Furnish and install new compressor and reconnect refrigerant lines and
wiring.
7. Leak test the repairs and evacuate system to 500 microns.
8. Perform a 1-hour vacuum decay test. Load 80 lbs. of new refrigerant into the
system.
9. Power up new compressor and commission.
10. Startup module for proper operation and performance.
D. BPHX (brazed plate heat exchanger) Cleaning of Modules 1 through 4
1. Equipment Information
Make: Multistack
Equipment Model #: MS080TC3H2W2AAC-R134A
Serial #: AE 02 63; AE 02 64; AE 02 65; AE 02 066
2. Condenser BPHX Scope
Lockout/Tagout machine electrically.
Isolate the brazed plate heat exchangers (BPHE) from the system by
closing the supply and return water valves.
Drain condenser piping and BPHE for each module.
Unbolt the Gruvlok couplings and remove from the 90 degree bend from
both the top and bottom (inlet and outlet) of each BPHE for cleaning
separately.
3. BPHE Scope
Install necessary fittings and adaptors on each BPHE individually to
attached Multistack BPHE cleaning machine.
Fill exchanger with water and scale dissolver solution (6 gallon each
BPHX mfg. recommendations).
Perform a hydrostatic test with cleaning pump.
Circulate Multistack scale-dissolver solution for (4) hours as per factory
recommendation.
4. Flushing Process
Add Scale Break Neutralizer solution to lower Ph to acceptable level to
flush and drain cleaning water and solution.
Add fresh water to the machine reservoir and circulate through HPHE
until water runs clear.
Reverse cleaning machine hoses and backflush any debris that may have
settled in the bottom of the BPHE. Repeat as needed.
Remove all fittings and disconnect cleaning machine.
Reinstall inlet and outlet header using new gaskets.
Backfill HPHE's headers and piping.
Open isolation valves and place machine back into service.
Startup module and check for proper operation and performance.
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