SECTION 23 52 30 PART 1 - GENERAL 1.01 RELATED WORK A. Section 23 05 00: Common Work Results for HVAC B. Section 23 25 00: Chemical Water Treatment C. Section 23 51 23: Flue Piping 1.02 QUALITY ASSURANCE A. Factory test in accordance with ASME code. 1. ASME Section IV heat exchanger rated for 160-PSI working pressure. 2. Fire test to verify operation and function of all controls. B. Standard for Manufacture: ASME Code for Boilers and Pressure Vessels and state and local boiler codes, and shall be UL listed for zero side clearance. C. Burner management system to follow requirements of Industrial Risk Insurers (IRI). D. Boiler plant shall comply with ASHRAE Standard 90.1 Energy Standard for Building. 1.03 SUBMITTALS A. Submit manufacturer's product data for review. 1.04 DOCUMENTS A. Provide the following documents to be delivered to the Owner upon completion of work: 1. Test Reports: 2. Factory Test 3. Performance Test 4. Certificates/Permits 5. ASME Certificate 6. National Board of Pressure Vessels Inspectors Certificate 7. Guarantee 8. Construction and Operating Permits, as required by state and local regulations, from Air Pollution Control Authorities. 9. Certificate of Acceptance or Boiler Operating Permit from State Boiler Inspector or insurance company. 1.05 PERMITS A. Obtain applicable construction and operating permits from local EPA, boiler, and insurance inspectors. PART 2 - PRODUCTS 2.01 ACCEPTABLE MANUFACTURERS A. Aerco International B. Patterson Kelly 23 52 30 - Page 1
2.02 BOILER - GENERAL A. Boiler shall be complete with all controls and accessories ready to operate on natural gas. B. Condensing Boiler Requirement: 1. Operating performance shall be no less than 86+ACU-thermal efficiency at all operating conditions; the efficiency shall increase as the firing rate decreases. The efficiency shall be in excess of 90+ACU- with low return water temperatures (100 degrees F). The manufacturer shall publish part-load efficiency curves showing multiple firing rates in relation to changing return water temperatures. The part-load efficiency shall be independently certified by Underwriter's Laboratory (UL). 2. Working Pressure: ASME rated for 160-psi maximum working pressure. 3. Heat exchanger fire tubes and tube sheets shall be constructed of 316L stainless steel. Vessel shall not have a pressure drop of more than 2 psig at 150 GPM. Boiler shall be capable of handling return water temperatures down to 40 degrees F without failure due to thermal shock or fireside condensation. 4. Individual boiler capacity shall not exceed 2MMBtu input to ensure conformance with Permit by Rule regulations. C. Boiler shall be of low mass, low water content and maintain header temperature to within 2 degrees F of set point at any point of operation and shall function without the need for dedicated supply pumps. D. Each boiler shall have a minimum turndown, 10:1 for 2 MMBH or less to prevent boiler cycling and aid in load matching to use the minimum amount of fuel necessary. E. Provide complete unit, skid-mounted on a steel base frame, complete with lifting lugs. F. Finish: Prime coat and finish coat with manufacturer's standard colors. G. Insulate vessel and other heat dissipating surfaces with fiberglass insulation. H. Provide necessary piping connections. I. Access to the tubesheets and heat exchangers are available by burner and exhaust manifold removal. Minimum access opening shall be no less than 10 in. diameter. J. The boiler shall be capable of sealed combustion operation. 2.03 BOILER TRIM A. Each boiler shall utilize an electric single seated combination safety shutoff valve/regulator with proof of closure switch in its gas train and incorporate dual over-temperature protection with manual reset in accordance with ASME Section IV and CSD-1. B. Pressure relief valves of a type and size required by ASME code. C. Drain valve, located at rear drain connection. 2.04 LOW NOx BOILER BURNER A. Construct burner and safety controls and sequence to meet local gas company codes and regulations. 23 52 30 - Page 2
B. Include electric safety fuel cutoff valves, gas electric ignition system, air pump assembly, pressure regulating devices, pressure and temperature indication. C. All burner material exposed to the combustion zone shall be stainless steel. D. Provide regulation required to reduce gas supply pressure from 2 psig to manufacturer's inlet design pressure. Verify gas supply pressure to burner controls. E. Low NOx Gas Burner: Fiber mesh with stainless steel body, spark ignition and flame rectification. 2.05 INTEGRAL FORCED DRAFT BLOWER A. The forced draft blower shall be factory assembled, wired, and mounted. 1. Forced draft fan. 2. Direct drive motor. B. The boiler plant shall be able to utilize a common stack without the use of remote fan assist devices. 2.06 BOILER CONTROL PANEL (EACH BOILER) A. Electrical equipment and wiring to conform to NEC and UL. B. Include current protection for all motors, magnetic starting switches, thermal overload and under voltage protection. C. Locate control devices and relays in splash-proof steel cabinet mounted on front of boiler. D. Motors 1/2 HP and over: 460/3/60. E. The control panel shall utilize individual circuit boards with a PID control system including an LED display board for temperature indication, fault message board and firing rate indication. All boards shall be field replaceable. F. The panel hardware shall support both RS-232 and RS-485 remote communications via BACnet open protocol. When the Building Automation System (BAS) does not have BACnet protocol capability and interoperability is required, the installing contractor shall provide a BACnet Gateway to act as interface/translator between the BAS via either the RS-485 port of the boiler control panel or the RS-232 port of the boiler plant master control panel. G. Combustion Safeguard: Electronic type detector for monitoring main flame and pilot. H. The control panel shall incorporate three self-governing selectable features designed to enhance operation in modes where it receives an external control signal by eliminating nuisance faults due to over-temperature, improper external signal or loss of external signal. These features include: Setpoint High Limit - allows for a selectable maximum boiler outlet temperature and acts as temperature limiting governor. Setpoint Low Limit - selectable minimum operating temperature and Failsafe Mode - to operate the boiler on internal set point upon loss of external control signal. I. Automatic recycling after power failure or normal operation of operating control. J. Lock out control, requiring manual reset, after pilot or main flame interruption, low water cutout, or high limit operation. 23 52 30 - Page 3
K. Control sequence of operation by boiler control panel on each boiler which is coordinated by a Boiler Management System (BMS) panel when multiple boilers are utilized. L. Provide pre-purge and post-purge cycles with full protection against flame failure during both ignition and normal burning periods. M. Conform to local gas company codes and regulations. N. Gas solenoid valves, diaphragm valves, hydraulic valves, regulators, etc., UL and IRI approved components and labeled individually. O. Manual/Automatic Switch in the control panel shall permit continuous firing at the selected rate when automatic firing not desired. 2.07 BOILER MANAGEMENT SYSTEM (BMS) A. Provide a master control panel when one or more boilers are utilized in the boiler plant. B. The BMS shall control up to 32 boilers and shall operate them simultaneously to maximize efficiency. C. The BMS shall be a standalone microprocessor based device used to efficiently operate one or more boilers in response to building load, weather or calendar functions. D. The BMS shall be equipped with open protocol serial connection port, RS-232 or RS-485, to report key operating parameters to the facility management system (FMS). Provide gateway connection as required to convert to building FMS. E. The BMS shall at a minimum have the following control: 1. Sequential or parallel boiler operation 2. Control signal for start/stop of auxiliary equipment 3. Time delay between individual unit start-up to limit utility peaks 4. Start next available unit if boiler malfunctions or is turne off 5. Adjustable programming for night, weekend, holiday setbacks 6. Safety interlock for make-up air dampers, pumps, etc. 7. Non volatile memory to store programming during power failures 8. Fault alarms for boilers and BMS 9. Programmable minimum and maximum temperatures and resets based on outside air temperature 10. Provided with PID and adaptive loops to allow for tight control of boiler firing and loop temperatures 11. Runtime equalization 12. Ability to allow for boiler operation in a continuous mode without being required to cycle on and off 13. Ability to accept commands from the FMS through the gateway connection for programming, setpoint adjustment or turning on/off boiler 2.08 GAS PIPING A. Provide all necessary gas piping properly valved between main and connection to burner and pilot. B. Size in accordance with national, state, and local ordinances and codes, and NFPA recommendations. 23 52 30 - Page 4
C. Gas cocks: Lubricated plug cocks with operating handles for manual shutoff. D. Gas burner piping assembly, including pilot, shall meet requirements of IRI. E. Provide vent-less gas regulator to reduce gas pressure from 2 psig to equipment operating pressure. 2.09 POLLUTION CONTROL A. Boiler shall be certified to meet South Coast Air Quality Management District (SCAQMD) and the Texas Commission on Environmental Quality (TECO) standards. PART 3 - EXECUTION 3.01 INSTALLATION A. Install boilers, boiler accessories and piping in accordance with NFPA, ASME, local codes, and manufacturer's instructions, insuring agency requirements. B. Boilers and accessories shall be installed and piped per manufacturer's recommendations and under his supervision. C. Pipe drains on boiler to the nearest drain, full size of the connection. D. Pipe relief valves and vents to outside the building. Size in accordance with manufacturer's recommendations and ASME code but not less than connection size. E. Pipe gas vent connections on gas controls to outside of the building. F. Install boiler stacks constructed of UL listed stainless steel AL-29-4-C positive pressure material. The manufacturer shall provide stack layout and bear the responsibility of proper operation. G. Each boiler shall have individual isolation valves for service and maintenance. 3.02 DUTIES OF SERVICE REPRESENTATIVE A. Boiler and burner manufacturer's factory trained service representative(s) to perform services described. 1. Work with installing Contractor, including site visits, to ensure proper equipment installation and piping. 2. Instruct personnel designated by maintenance personnel in operation and maintenance of equipment. B. Service representative shall supervise the following: 1. Adjustment of firing equipment. a. Representative shall have the test equipment, tools, and instruments necessary to accomplish this work. 1) Boiler performance demonstration. 2) Adjustment of firing equipment. 2. Setup of BMS with reset slopes, outside air temperature data and time of day schedules in conjunction with the building control system. 3. Coordination of owner s water treatment vendor startup activities for heating water loops. 23 52 30 - Page 5
3.03 CLEANING (WASH OUT) A. Insure maintenance personnel and water treatment company representative are present, the required chemicals are present for the procedures required herein, and water treatment equipment is installed and functioning. B. Before boilers and heating system are placed in service, either for temporary or permanent use, clean and flush piping system prior to boiler connection and start-up. 3.04 START-UP A. Verify safety relief valve is installed properly. B. Adjust firing equipment. C. Operate each boiler for a minimum of one hour at each 1/4, 1/2, 3/4, and full loads. D. Take readings every half hour during the above operation for the following: 1. Stack temperature. 2. Boiler water temperature in and out. 3. Percent carbon dioxide and oxygen readings. E. Adjust fuel/air mix to maximum combustion efficiency while meeting low nitrous oxide emissions set forth by the State of Texas. 3.05 OPERATING DEMONSTRATION A. Demonstrate to Owner the operation of the system over entire range. B. Demonstrate to Owner the operation of total system as a unit boilers and control system. 3.06 WARRANTY A. The pressure vessel/heat exchanger of the boiler shall carry a non-prorated 7-year warranty against failure due to condensate corrosion, thermal stress, mechanical defects or workmanship. The control panel assembly shall carry a 2-year warranty against failure due to defective materials or workmanship. The BMS assembly shall carry a 2-year warranty against failure due to defective materials or workmanship A Warranty Certificate must be issued to the owner from the manufacturer and a copy of warranty must be submitted for engineer's approval. END OF SECTION 23 52 30 - Page 6