Section 15512 - Cast Iron Boilers 15512 - Cast... · SECTION 15512 CAST – IRON BOILERS Clark County DOA Standard Specifications – 15512 Ver. 1.0 September 5, 2005 Page 1 of 9

SECTION 15512

CAST – IRON BOILERS

Clark County DOA Standard Specifications – 15512 Ver. 1.0 September 5, 2005

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PART 1 - GENERAL 1.1 RELATED DOCUMENTS

A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Specification Sections, apply to this Section.

B. Related Sections include the following:

1. Section 15189 "HVAC Water Treatment" for feedwater treatment and connections.

2. Section 15550 "Breechings, Chimneys, and Stacks" for connections to breechings, chimneys, and stacks.

3 Sections 15900 “HVAC Instrumentation and Controls” for control wiring for automatic temperature control.

1.2 SUMMARY

A. This Section includes fuel-fired, cast-iron, heating hot-water boilers and accessories. 1.3 SUBMITTALS

A. Product Data: Include rated capacities; shipping, installed, and operating weights; furnished specialties; and accessories for each model indicated.

B. Shop Drawings: Detail equipment assemblies and indicate dimensions, required

clearances, method of field assembly, components, and location and size of each field connection. 1. Wiring Diagrams: Detail wiring for power, signal, and control systems and

differentiate between manufacturer-installed and field-installed wiring.

C. Source Quality Control Tests and Inspection Reports: Indicate and interpret test results for compliance with performance requirements before shipping.

D. Field Test Reports: Indicate and interpret test results for compliance with performance

requirements. E. Maintenance Data: Include in the maintenance manuals. Include parts list, maintenance

guide, and wiring diagrams for each boiler. 1.4 QUALITY CONTROL

A. Listing and Labeling: Provide electrically operated components specified in this Section that are listed and labeled. 1. The Terms "Listed" and "Labeled": As defined in NFPA 70, Article 100. 2. Listing and Labeling Agency Qualifications: A "Nationally Recognized Testing

Laboratory" as defined in OSHA Regulation 1910.7.

B. ASME Compliance: Fabricate and label boilers to comply with the ASME Boiler and Pressure Vessel Code: Section IV, "Heating Boilers."

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C. FM Compliance: Control devices and control sequences according to requirements of FM.

D. I=B=R Compliance: Boilers tested and rated according to the Hydronics Institute's

"Testing and Rating Standard for Heating Boilers," with I=B=R emblem on a nameplate affixed to the boiler.

E. IRI Compliance: Control devices and control sequences according to requirements of

IRI. F. Comply with NFPA 70 for electrical components and installation.

1.5 COORDINATION

A. Coordinate size and location of concrete bases. Concrete, reinforcement, and formwork requirements are specified in Division 3 Section "Cast-in-Place Concrete."

1.6 WARRANTY

A. General Warranty: The special warranty specified in this Article shall not deprive the Owner of other rights the Owner may have under other provisions of the Contract Documents and shall be in addition to, and run concurrent with, other warranties made by the Contractor under requirements of the Contract Documents.

B. Special Warranty: Submit a written warranty, executed by the contractor for the heat

exchanger. 1. Warranty Period: Manufacturer's standard, but not less than 10 years from date

of Substantial Completion. PART 2 - PRODUCTS 2.1 MANUFACTURERS

A. Available Manufacturers: Subject to compliance with requirements, manufacturers offering boilers that may be incorporated into the Work include, but are not limited to, the following:

B. Manufacturers: Subject to compliance with requirements, provide boilers by one of the

following: 1. Bryan 2. Cleaver Brooks 3. Ajax Boiler Company

2.2 BOILERS AND TRIM - GENERAL

A. All equipment or apparatus of any one system must be the product of one manufacturer or equivalent products of a number of manufacturers which are suitable for use in a unified or assembled system.

B. All materials or equipment to be furnished under this Contract shall be new, American

made and shall conform to the grade, quality and standards specified herein. Major items of equipment shall be the latest standard products as advertised in printed catalogs

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by reputable manufacturers for the purpose intended and shall have replacement parts available.

C. Mechanical fastenings used throughout the equipment on parts subject to wear and

replacement shall be of a type capable of removal and replacement without physical deformation.

D. Belts, pulleys, chains, gears, couplings, projecting set screws, keys and other rotating

parts shall be fully enclosed or properly guarded. E. When equipment is relocated to a place other than that shown on the Drawings or when

equipment other than that specified is used, the Contractor shall pay the entire cost of required revisions to such items as structural steel, concrete, electrical work, piping and ductwork.

F. All equipment installation shall conform to the recommendations and standards of the

respective manufacturers. The installer shall obtain these recommendations and standards and shall review them prior to the actual installation of the work. Where the contract documents indicate deviation from manufacturer's recommendations or standards, the Contractor shall call such deviations to the attention of the Owner before proceeding with the work. In all cases, work shall be subject to approval by the Owner.

2.3 HOT WATER BOILERS TRIM

A. Each hot water boiler shall be provided with the following trim:

1. ASME NB labeled safety relief valve with hand test lever rated for not less than the boiler burner output capacity. These valves shall be of the type designed for hot water use. Pressure relief rating shall not be in excess of thirty (30) psig for cast iron boilers regardless of static water pressure in the system, and a pressure relief rating shall not to be in excess of six (6) psig above the maximum allowable working pressure for pressure up to and including sixty (60) psig, and ten (10) percent of maximum allowable working pressure over sixty (60) psig for steel boilers, regardless of static water pressure in the system.

2. Safety relief valve discharge pipe shall be piped at full size of valve discharge to within six (6) inches of the floor.

3. External low water cut off (manual reset) arranged and wired to cut off burner on fall in water level below the safe water level of the burner.

4. Paddle type flow switch to be mounted in the boiler return nozzle and wired to the burner control to stop the burner and fuel supply when flow is not detected.

5. A minimum four and one half (4 1/2) inch water pressure gauge with a scale equal to a minimum of one and one half times the maximum boiler operating pressure. The gauge shall be mounted directly on the boiler.

6. A dial or column type hot water thermometer 250 deg. F maximum temperature, which shall be located to indicate the true temperature of the water. This device may be provided as a separate device or as a combination device with the pressure gauge.

7. Boiler drain valve opening(s) with valves so installed to completely drain the boiler.

8. High hot water temperature cut off (manual reset) which shall be located to sense the true temperature of the water.

2.4 BURNERS

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A. Each hot water boiler shall be provided with a combination multiple orifice flame retention

type burner, which is the boiler manufacturer's standard offering which meets the performance requirements and contains the features outlined in this Specification.

B. Each burner shall be capable of being fired using natural gas with a heating value of

1000 Btu's per standard cubic foot. Available natural gas pressure will be approximately seven (7) inches water gauge.

C. Burner output shall be controlled using Lo Hi Lo Off method for burners 1500 MBTUH

gross output and smaller and shall be controlled using modulating method for burners with greater than 1500 MBTUH gross output. Minimum required turndown on modulating burners shall be 4 to 1. Burner shall always return to low fire position for ignition and burner shall provide ignition and then shall be fired at low fire until the boiler water temperature or pressure reaches the minimum temperature or pressure required to prevent thermal shock or condensation on the boiler surface. Burner control shall be provided with purge cycles which are initiated before starting a burner and following shut down of the burner.

D. The gas train shall be IRI approved type consisting of:

1. Main gas shut off valve. 2. Gas pressure regulator with vent. 3. Low gas pressure interlock 4. Two (2) normally closed motorized safety shut off valves. 5. Normally open solenoid vent valve (connected between two motorized safety

shut off valves). 6. Gas test vent. 7. Gas shut off valve (down stream of test vent). 8. Two (2) unions for removal of main gas train. 9. Gas pilot shutoff valve. 10. Gas pilot manifold valve and regulator. 11. Pilot. 12. Butterfly firing valve with operator. 13. High gas pressure interlock.

E. Gas pilot shall be of premix type with automatic electric ignition. Electronic detector shall

monitor pilot so that primary fuel valve cannot open until pilot flame has been established.

H. Combustion air shall be provided by a forced draft blower. Blower shall be complete with

air damper with operator and sound attenuator section on the combustion air inlet. Motors shall be the standard motors provided by the burner/boiler manufacturer for application. See the boiler schedules for the motor electrical requirements.

I. Ignition system shall include:

1. Ultraviolet flame detector 2. Combustion airflow switch 3. Gas electric ignition assembly consisting of a pilot burner, 6000 volt ignition

transformer, spark plug, and gas pilot valve fuel train.

J. Fuel air control shall provide two position or modulating adjustment of the combustion air damper, and the butterfly gas valve, and the fuel oil metering valve using an electric positioning motor. Fuel air control shall work in conjunction with a temperature controller for hot water boilers.

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K. The burner control cabinet(s) shall be a NEMA I enclosure complete with the following:

1. Power on off automatic switch with light which illuminates with automatic mode. 2. Electronic flame safeguard and programmer. 3. Manual potentiometer or Hi Lo fire switch. 4. A "stop" switch. 5. A manual gas/oil fire selector switch. 6. A main fuel light. 7. A low water light. 8. A flame failure light. 9. An ignition failure light. 10. A main flame light. 11. An alarm contact for remote detection of failure of any safety device. 12. Remote "start" contacts. 13. Numbered terminal strip for connection of all externally mounted devices

including remote ON OFF, low water cutoff(s), high (temperature) pressure, flow switch.

14. Fused and grounded step down control transformer (115 volt 1 phase) for all control devices.

15. All required control devices and relays not mounted on the boiler or its piping. 16. Magnetic starters with overload protection for the burner motors.

2.6 BOILER LEAD LAG CONTROL PANEL

A. Each boiler system shall be provided with a lead lag control panel. Control panel shall be furnished by the boiler manufacturer and installed by the contractor including wiring.

B. Panel shall be a minimum NEMA I apparatus control panel, powered by an independent

115 volt power source. Refer to 15900 for further functional requirements. 2.7 BOILER (CAST IRON WATER)

A. The boilers shall be of a lower pressure sectional, gray or ductile cast iron wet base design and constructed in accordance with the provisions of Section IV of the ASME Boiler and Pressure Vessel Code and shall be stamped with the required official ASME symbol. The boilers shall be tested, approved and listed by IBR. The boiler shall be capable of developing full IBR gross output capacity of one hundred percent firing rate and include the IBR symbol of certification.

B. Each boiler section and/or complete section assembly shall be hydrostatically pressure

tested before shipment in accordance with Section IV of the ASME Boiler and Pressure Vessel Code.

C. The boiler shall be factory assembled and/or completely assembled at the job site at the

Contractor's option. Refer to Drawings for notes and requirements pertaining to installation. The Contractor shall provide for field assembly where required by space constraints. Field assembly shall be provided in accordance with the manufacturer's installation instructions.

D. Each boiler shall be suitable for hot water system and be stamped for a maximum

working pressure of 30 psig.

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E. Each boiler section shall be evenly spaced with spacing pads to eliminate corrosion from long iron to iron contact and sealed with heavy rope for complete retention of the products of combustion.

F. A clean out plate shall be provided on the front of boiler for inspection and easy cleaning

of flue ways to maintain high boiler efficiency. G. The boiler shall be provided with flame observation ports in the front and back section. H. The boiler shall be provided with adjustable damper to adjust for proper air/products of

combustion flow through the boiler; this damper shall be securely locked in position after desired combustion and pressure readings are obtained.

I. Boiler sections shall be full wet base design for maximum heat absorption and low floor

temperatures. J. Boilers shall include inspection and cleanout tappings located on side at the bottom

and/or on the side above the crown sheet in the front and back sections. K. Boilers shall be complete with burner and trim.

2.9 MOTORS

A. Refer to Section 15055 "Motors" for factory-installed motors. B. Motor Construction: NEMA MG 1, general purpose, continuous duty, Design B. C. Enclosure Type: Open drip-proof motors where satisfactorily housed or remotely located

during operation. 2.10 SOURCE QUALITY CONTROL

A. Test and inspect boilers according to the ASME Boiler and Pressure Vessel Code, Section IV for low-pressure boilers.

PART 3 - EXECUTION 3.1 EXAMINATION

A. Examine area to receive boiler for compliance with requirements for installation tolerances and other conditions affecting boiler performance. Do not proceed with installation until unsatisfactory conditions have been corrected.

3.2 INSTALLATION

A. Install boilers level and plumb, according to manufacturer's written instructions and referenced standards.

B. Install gas-fired boilers according to NFPA 54.

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C. Support boilers on 4-inch- (100-mm-) thick concrete base, 4 inches (100 mm) larger on each side than base of unit. Dowel base to floor on 18-inch (450-mm) centers along perimeter of base. Cast anchor-bolt inserts through base into floor.

D. Assemble boiler sections in sequence and seal between each section. Assemble boiler

trim according to manufacturer's written installation instructions. E. Install electrical devices furnished with boiler, but not specified to be factory mounted.

3.3 CONNECTIONS

A. Connect gas piping full size to boiler gas-train inlet with union. B Connect hot-water piping to supply- and return-boiler tappings with shutoff valve and

union or flange at each connection. C Install piping from safety-relief valves to nearest floor drain. D Install piping from safety valves to drip-pan elbow and to nearest floor drain. E. Connect breeching to boiler outlet, full size of outlet. F. Electrical: Comply with applicable requirements in Division 16 Sections. G. Ground equipment.

1. Tighten electrical connectors and terminals according to manufacturer's published torque-tightening values. If manufacturer's torque values are not indicated, use those specified in UL 486A and UL 486B.

3.4 FIELD QUALITY CONTROL

A. Manufacturer's Field Service: Engage a factory-authorized service representative to supervise the field assembly of components and installation of boilers, including piping and electrical connections. Report results in writing. 1. Test and adjust controls and safeties. Replace damaged and malfunctioning

controls and equipment.

B. Hydrostatically test assembled boiler and piping, according to applicable sections of the ASME Boiler and Pressure Vessel Code.

3.5 CLEANING

A. Flush and clean boilers on completion of installation, according to manufacturer's written instructions.

B. After completing boiler installation, including outlet fittings and devices, inspect exposed

finish. Remove burrs, dirt, and construction debris and repair damaged finishes including chips, scratches, and abrasions with manufacturer's touchup paint.

3.6 START UP SERVICE

A. Engage a factory-authorized service representative to provide startup service.

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B. Verify that installation is as indicated and specified.

1. Verify that electrical wiring installation complies with manufacturer's submittal and installation requirements in Division 16 Sections. Do not proceed with boiler startup until wiring installation is acceptable to equipment Installer.

C. Complete manufacturer's installation and startup checklist and verify the following:

1. Boiler is level on concrete base. 2. Flue and chimney are installed without visible damage. 3. No damage is visible to boiler jacket, refractory, or combustion chamber. 4. Pressure-reducing valves are checked for correct operation and specified relief

pressure. Adjust as required. 5. Clearances have been provided and piping is flanged for easy removal and

servicing. 6. Heating circuit pipes have been connected to correct ports. 7. Labels are clearly visible. 8. Boiler, burner, and flue are clean and free of construction debris. 9. Burner blower rotates in correct direction. 10. Pressure and temperature gages are installed. 11. Control installations are completed.

D. Ensure pumps operate properly. E. Check operation of pressure-reducing valve on gas train, including venting. F. Check that fluid-level, flow-switch, and high-temperature interlocks are in place. G. Start pumps and boilers, and adjust burners for maximum operating efficiency.

1. Fill out startup checklist and attach copy with Contractor Startup Report. 2. Check and record performance of factory-provided boiler protection devices and

firing sequences. 3. Check and record performance of boiler fluid-level, flow-switch, and high-

temperature interlocks. 4. Run-in boilers as recommended or required by manufacturer.

H. Perform the following tests for each firing rate for high/low burners and for 100, 66, and 33 percent load for modulating burners. Adjust boiler combustion efficiency at each firing rate. Measure and record the following: 1. Gas pressure on manifold. 2. Combustion-air temperature at inlet to burner. 3. Flue-gas temperature at boiler discharge. 4. Flue-gas carbon-dioxide and oxygen concentration. 5. Natural flue draft.

I. Measure and record water flow rate, pressure drops, and temperature rise through each boiler.

J. Inspect expansion tank, makeup water meter, tank pressure, pressure-reducing valve,

water level, and backflow preventer. 3.7 TESTS AND GUARANTEES

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A. Efficiency Guarantee Complete unit shall be guaranteed to operate at a fuel to gross heat output efficiency of 80 percent or greater over the operating range, when fired with either gas or oil. This efficiency shall be field verified at boiler startup.

B. Shop Test Complete packaged boiler shall receive factory tests to check construction,

operation and function of all controls. C. After the burners and combustion control systems have been placed in operation, all

equipment shall be adjusted for maximum combustion efficiency. In the process of effecting these adjustments, a combustion efficiency test shall be conducted with the use of an absorption type analyzer capable of measuring carbon dioxide, oxygen and carbon monoxide. This test shall continue for the length of time necessary to adjust the burners for maximum efficiency at 100, 75, 50 and 25 percent of rating. Stack temperature, overfire draft, carbon dioxide and oxygen shall be recorded. A written report on the combustion test shall be rendered in duplicate to the Owner.

3.8 DEMONSTRATION

A. Engage a factory-authorized service representative to train Owner's maintenance

personnel as specified below:

1. Operate boiler, including accessories and controls, to demonstrate compliance with requirements.

2. Train Owner's maintenance personnel on procedures and schedules related to startup and shutdown, troubleshooting, servicing, and preventive maintenance.

3. Review data in the maintenance manuals. Refer to Section "Contract Closeout." 4. Review data in the maintenance manuals. Refer to Section "Operation and

Maintenance Data." 5. Schedule training with Owner with at least 7 days' advance notice.

B. Boiler manufacturer's local representative shall provide proof of his ability to render

competent service for the maintenance and repair of all equipment on a 24 hour basis. He shall further attest that a complete inventory of parts, controls, etc. is maintained locally and that an effective service organization with these qualifications has been maintained locally for five (5) years or more.

END OF SECTION