Division 43 Process Gas and Liquid Handling, Purification, and Storage Equipment

Transcription

1 Division 43 Process Gas and Liquid Handling, Purification, and Storage Equipment

2 Part 1 General Section Waste Gas Burner 1.01 Summary A. Section Includes: Waste gas burner with flare and ignition system. Includes auto ignition system, valves, package control system and appurtenances. B. The equipment specified herein is intended to replace obsolete equipment, which is being demolished Submittals A. Shop Drawings: Submit in accordance with Section , Submittal Procedures, covering the items included under this Section. Shop Drawing submittals shall include: 1. Product data for each gas piping specialty and special duty valve. Include rated capacities of selected models, furnished specialties and accessories, and installation instructions. 2. Shop Drawings detailing dimensions, required clearances, for connection to gas meter. 3. Coordination drawings for gas distribution piping systems. B. Record Drawings: At Project closeout, submit record drawings of installed products, in accordance with requirements of Section , Closeout Procedures. C. Test and Inspection Report: A written report shall be submitted to ENGINEER documenting testing and/or inspection results. The report shall be prepared as noted under Section , Product Requirements. D. Operation and Maintenance Manuals: Submit in accordance with requirements of Section , Closeout Procedures, operation and maintenance manuals for items included under this Section Quality Assurance A. Qualifications for Welding Processes and Operators: Comply with the requirements of ASME Boiler and Pressure Vessel Code, "Welding and Brazing Qualification." B. Regulatory Requirements: Comply with the requirements of the following codes: 1. Michigan Mechanical Code. 2. BOCA Basic National Mechanical Code Sequencing and Scheduling A. Work Interruptions: When interruptions in work occur while repairs or alterations are being made to an existing piping system, leave the system in safe condition. B. Coordinate the installation of pipe sleeves for foundation wall penetrations CNG F

3 1.05 Maintenance A. Valve Wrenches: Furnish to OWNER, with receipt, two valve wrenches for each type of gas valve installed, requiring same. Part Products Manufacturers A. Available Manufacturers: Subject to compliance with requirements, manufacturers offering gas piping system products which may be incorporated in the work include, but are not limited to, the following: 1. Varec, Series 244WS. 2. Or equal Burner A. Waste Gas Burner: Provide a waste gas burner with pilot gas supply and flame check, sizes and capacities as shown in the Schedule. 1. Burner shall be self-supporting on 150 pound ANSI flange for winds to 150 mph and shall meet Seismic Zone 4 requirements.. Burner shall be constructed with a 304 stainless steel shroud and upper 24 inches of stack and pilot piping. Remainder of burner stack shall be mild steel. Pilot nozzles and thermocouple shall be 316 stainless steel. Thermowell shall be inconel Pilot Gas A. Continuous flame nozzle shall be mounted integral to the burner and shall have a long profile flame. Pilot shall be inclined 45 degrees off vertical. Pilot flame shall extend through waste gas flow profile to ensure ignition of waste gas regardless of the flow rate. B. Unprotected pilot shall withstand winds up to 110 mph (177 km/h) without the use of downdraft protectors, vortex vanes or other flow restricting devices. C. Provide a waste gas burner that will allow operation using pilot gas supply pressure of 4" WC minimum to a maximum of 21 WC. D. Waste gas burner shall operate using only one of the following pilot gas at 4 WC supply pressure: 1. natural gas, 65 SCFH 2. propane, 45 cfh 3. digester gas with minimum heat content of 550 BTU/cubic ft or greater as pilot fuel, 55 SCFH. E. Pilot gas only runs continuously when there is a demand to flare or combust waste gas, otherwise the burner remains on standby and does not continuously use pilot gas CNG F

4 F. Pilot gas and air shall be mixed and ignited at ground level, remote from the burner stack. Specifically, no component of the ignition system shall be mounted to the burner stack or shroud; nor shall heat shields be substituted in an attempt to protect such devices from the heat of combustion. 1. Theory of Operation A. The pilot ignition system shall utilize flame front technology. 1. A pressure switch or PLC signal (choose one) installed on the main gas line, initiates start-up sequence through the remote start contacts. 2. This contact closure energizes the Remote-Start timer to eliminate nuisance switching and false starts. 3. The start-up sequence will open the continuous pilot solenoid valve and the flame retention solenoid valve. 4. The continuous pilot line receives a constant air/gas supply from the mixing chamber. 5. The system will purge for "spark interval set time" minutes. 6. The transformer sends a voltage to the spark plug. 7. This generates a flame front, which ignites the gas from continuous flame nozzle. 8. The thermocouple located inside the continuous flame nozzle heats up. When it exceeds its temperature set point, the retention solenoid valve closes. Pilot ON light comes on in the control panel. 9. The explosion proof solenoid valve on the pressure relief and flame trap assembly is energized close, opening the regulator and permitting flow of digester gas to the burner for combustion. 10. Local Start Operation In AUTO mode, the burner and the pilot will remain lit and will attempt re-ignition in case the pilot is lost. Ignition will continue to happen until the PILOT ON indicating light comes on in the panel or when a second timer times out. 11. Remote Start Operation a) If the thermocouple cools below its set point, Pilot ON turns off and PILOT OFF comes on and re-ignition will occur. b) A system alarm will come on indicating a pilot flame failure if the thermocouple does not heat up above its setpoint within the set time. The unit would have to be manually reset. c) If the pressure in the waste gas line drops below the pressure switch setpoint or the plant permissive signal is lost, the "Remote Start" time delay relay will begin timing and delay switching until it times out providing a delayed pilot shutdown to prevent nuisance switching CNG F

5 2. Pilot Gas Control Components d) Once the time delay relay times out, the Continuous Pilot Gas Supply solenoid valve will close. e) Once the thermocouple cools below its set point, the LED pilot light will switch from green to red. f) OPTION: The contacts for the three-way solenoid valve on the pressure relief regulator changes closing the regulator. g) The burner is now in STANDBY mode. h) The system alarm relay will not activate while in STANDBY mode. i) Total system will remain in standby mode until the Remote Start contacts close initiating pilot start-up ignition sequence. A. The pilot gas control components shall be mounted on a stainless steel plate with weatherhood and mounting stand. The control panel will also be mounted on the same plate. B. It must be installed a maximum of 70 feet horizontal distance from the flare. The pilot gas piping from the pilot gas control components panel to the waste gas burner connection may have 45 deg. elbows to connect to the pilot gas connections in the burner stack. The pilot gas piping and venturi are at an incline to maximize air-gas mixing. C. Pilot Gas Components include: 1. XP Solenoid valves with aluminum construction and stainless steel inserts. 2. Pressure gauges, 0-30 inches WC range min 3. Isolation valves 4. 2-inch 347 SS inspirating venturi. 5. air blower 6. All tubing and threaded fittings shall be provided in stainless steel D. Gas inlet connection shall be 1 NPT. Gas outlet connections shall be 2 NPT to the continuous flame line and 1/2 NPT to the flame retention line. Pilot gas and air shall be mixed and ignited remote from the burners of the burner stack. Specifically, no component of the ignition system shall be mounted to the burner stack assembly. 3. Burner Controls Control Panel shall include the following features: A. NEMA 4X, 316 SS construction B. Three-position selector switch for OFF/HAND/AUTO modes C. Pilot flame monitoring D. Status lights for "Pilot On", "Pilot Off", "Spark", " Retention Valve" CNG F

6 E. Adjustable thermocouple set point. F. Heater and thermostat G. Manual ignition button H. SPDT contacts for remote indication of Pilot On/Off and Pilot Flame Failure functions I. 120 VAC, single phase, 60 Hz. J. Capability for repeated ignition cycle. K. 10 amps, grounded neutral. L. UL certified. The Control panel shall include necessary pilot controls to provide automatic re-ignition of the burner. It will provide flame sensing and re-ignition sequence in case the pilot is lost. In case of a pilot flame failure, the solenoid valves shall fail close. Part 3 Execution 3.01 Preparation A. Precautions: Before turning off the gas to the premises, or section of piping, turn off all equipment valves. Perform a leakage test as specified in "FIELD QUALITY CONTROL" below, to determine that all equipment is turned off in the piping section to be affected. B. Conform to the requirements in NFPA 54, for the prevention of accidental ignition Piping Installations A. General: Conform to the requirements of NFPA 54 - National Fuel Gas Code. B. Install pipe sleeve and seals at foundation and basement wall penetrations. C. Seal pipe penetrations through fire barriers using fire barrier penetration sealers. D. Drips and Sediment Traps: Install a drip leg at all low points where condensate may collect. E. Install gas piping at a uniform grade of 1/4-inch in 15 feet, upward to risers, and from the risers to the meter, or service regulator when meter is not provided, or the equipment. F. Make reductions in pipe sizes using eccentric reducer fittings installed with the level side down. G. Connect branch outlet pipes from the top or sides of horizontal lines, not from the bottom Field Quality Control A. Piping Tests: Inspect, test, and purge digester gas piping with nitrogen at 50 psig CNG F

7 DIGESTER GAS SYSTEM EQUIPMENT SCHEDULE Waste Gas Burner: Size: Pilot Gas Supply: Gas Type: Flame Check Size: Burner Capacity: Gas to be Flared: 2-inch 1/2-inch Natural gas 1/2-inch on pilot line 3850 scfh at 4 w/c. Digester Gas, 65% methane End of Section CNG F

8 SECTION CENTRIFUGAL SEWAGE PUMPS PART 1 - GENERAL 1.01 SUMMARY A. Section Includes: Labor, materials, and equipment necessary for furnishing the fabrication, production and installation of dry pit sewage pumps as shown on Drawings or listed on Schedule REFERENCES A. Reference Standards: 1. AISI C1141 Steel 2. ANSI Class 125 Flanged Dimensions 3. ANSI B.11 Bearings 4. ASTM A 48 Cast Iron 5. ASTM A 532 Abrasion-Resistant Cast Irons 6. SAE 1045 Steel 7. SAE 4140 Steel 1.03 SYSTEM DESCRIPTION A. Performance Requirements: Except where noted, each pump shall be designed to operate continuously at the specified duty point with available net positive suction head as shown without cavitation and without requiring throttling to prevent cavitation or overloading the motor. Multiple pumps running concurrently shall also satisfy the above condition. B. Pump/Motor Coupling: Close coupled pumps with common motor and impeller shafts will not be acceptable unless specifically called for on Schedule. C. Suction Requirements: Velocities at the pump casing inlet shall not exceed 20 feet per second at the specified duty point. The pump manufacturer shall provide suction reducing elbows if required to provide a reduction of not more than 2 standard pipe diameters per fitting between the suction header and the pump casing inlet. D. Characteristic Curves: Constant speed pumps' characteristic curves must have a continuous test rise from duty point to shutoff head. Shutoff head must be a minimum of 10 feet above duty point unless stated otherwise on Schedule. 1. Variable speed pumps' characteristic curves shall have a minimum shutoff head as noted on Schedule SYSTEM RESPONSIBILITY A. Pump manufacturer may rely upon information on Pump Schedule pertaining to steady-state operating conditions (flow, TDH, NPSHA, etc.). However, pump manufacturer shall be responsible to review this Specification Section, relevant pipework Drawings, schematics, and electrical and instrumentation Drawings to ensure that equipment offered is suitable for the purposes intended by the Contract Documents. Refer questions and clarifications to ENGINEER CNG F

9 1.05 SUBMITTALS A. Shop Drawings: Submit in accordance with Section , Submittal Procedures covering the items included under this Section. B. Test and Inspection Report: A written report shall be submitted to ENGINEER documenting testing and/or inspection results. The report shall be prepared as noted under Section Product Requirements. C. Operation and Maintenance Manuals: Submit in accordance with requirements of Section Submittal Procedures, operation and maintenance manuals for items included under this Section. D. Warranty: Submit in accordance with requirements of Division 1, warranties covering the items included under this Section. PART 2 - PRODUCTS 2.01 MANUFACTURERS A. Subject to compliance with specified requirements, manufacturers offering products which may be incorporated in Work include: 1. Double Mechanical Pump Seals: a. John Crane Co., Type 21. b. Durametallic Corp., Double CRO. c. Or Equal 2. Centrifugal Sewage Pumps: a. Fairbanks-Morse. b. Clow Yeomans c. Or Equal 2.02 EQUIPMENT A. Pumps shall be vertical or horizontal in the respective capacities and duty points as listed on Schedule. B. The discharge head will consist of the static lift plus the friction head in the suction and discharge piping. Special suction conditions, if required, are as shown on Schedule. Self-priming pumps shall be furnished where called for on Schedule. C. The total dynamic head stated on Schedule shall be developed by the pumping units. Any losses incurred between the suction and discharge connections furnished with the pump are not included. D. Pumps shall be used to pump sewage and shall be of the nonclog type capable of passing solid spheres up to 3 inches in diameter. E. Pump speeds shall not exceed the speeds listed on Schedule. The pumps shall be arranged as nearly as the types will permit to those indicated on Drawings with direction of rotation as required by the installation COMPONENTS A. Motors: Electric motors shall be of the vertical or horizontal shaft as required. Each motor shall be provided with a suitable thrust bearing which shall carry the load of the rotor together with that of such parts of the shaft as may not be carried by the pump. 1. Pump motor nameplate horsepower shall be sufficient for nonoverloading operation at all points on the performance curve of the impeller selected to meet the duty point including horsepower requirements of CNG F

10 the drive. At no point shall the required brake horsepower exceed 85 percent of the motor nameplate horsepower multiplied by the motor service factor. 2. Motors shall comply with the specifications set forth in Section Electrical Motors and with details outlined on Schedule. B. Anchor Bolts: All anchor bolts shall be stainless steel unless otherwise noted and furnished under this Section DRY PIT PUMPS A. Casing: Pump casings shall be made of cast iron of suitable thickness to withstand the specified pressures. Casings shall be tested with internal hydrostatic pressures of at least 50 psi, and under this test pressure they shall show no leakage or distortion. The casings shall be provided with suitable openings for priming connections, air vents, drainage, gauges, and suitable eye bolts for lifting. A 1/4-inch minimum IPS tap, fitted with a threaded plug, shall be provided on the pump suction and discharge. Pumps shall have ANSI, Class 125 flat-face flanged suction and discharge connections machined so as to make a watertight joint using thin paper gaskets. 1. Machined fittings for casing parts shall be accurately aligned and identical so that casing may be installed for either clockwise or counterclockwise direction of rotation. Casing shall be so arranged that the impeller may be removed without disturbing either suction or discharge piping. 2. Each pump shall be provided with a pump casing handhole and cover plate, or a straight or reducing elbow-type suction nozzle bolted with suitable make-up piece to the casing, with large hand hole, with quick opening cover for permitting access to the interior of the pump casing. T B. Impellers: Impellers shall be of the single suction nonclog type. Impellers shall be constructed of close-grained cast iron, carefully machined, balanced statically and dynamically, finished smooth inside and outside, and firmly secured to the shaft. C. Shaft: The pumps shaft shall be high grade carbon steel, SAE 1045 minimum, machined true, straight, and round and of sufficient size to transmit full driver output. They shall be fitted with removable sleeves of hardened 304 or 316 stainless steel compatible with the mechanical seal mounting requirements where they pass through the stuffing boxes or are in contact with sewage. All other parts of the shaft shall be finished and polished. Where required, wearing and sealing rings shall be water sealed. Wearing rings, shaft sleeve, and packing gland shall be of a corrosion-resisting material. D. Stuffing Box: The stuffing box head shall be a close-grained cast iron, bolted to the volute. It shall contain a stuffing box designed to accommodate, interchangeably, either a double mechanical seal or graphiteimpregnated packing with lantern ring. The stuffing box shall be tapped in a convenient location for a sealing water connection. E. Seals: When indicated on Schedule, pumps shall be equipped with an O-ring type, friction drive, double, mechanical seal. Rotating elements shall be high-grade carbon. Stationary elements shall be silica-free ceramic or tungsten carbide. Springs shall be Hastelloy B or C, and all other wetted parts shall be stainless steel. O- rings shall be Viton Stationary element shall be self-aligning. Seal faces shall be true to a tolerance of 2 Helium light band ( inch). Rotating elements shall be securely fixed to the shaft with setscrews. 2. One spare seal shall be provided for each set of 1 or 2 pumps of the same size in each station, and 2 spare seals shall be provided for each set of more than 2 pumps of the same size for each station. Spare seals shall be packaged for long-term storage. F. Coupling: A flexible coupling with a guard shall be provided between the pump and motor. G. Vertical pumps shall have a sturdy base supporting the pump casing. Base shall be designed to provide easy access to the cleanout on the suction elbow. The base shall be drilled for its attachment to a concrete base above the floor upon which the pump is placed CNG F

11 H. Bearings: Bearings shall be antifriction ball or roller type. Lubrication shall be grease and fittings shall be provided for lubrication and cleaning. Bearings shall be designed for AFBMA recommendations with a rating life of B-10, 100,000 hours for the loads imposed by operating the selected pump at a flow equal to 35 percent of the flow at the best efficiency point, with design maximum speed and maximum impeller diameter. I. Motor Support: Vertical pumps shall be provided with a fabricated steel motor support. Motor supports that bolt directly on the pump shall be designed to permit access to the frame, coupling, and stuffing box. Motor supports that mount externally from the pump shall be designed to permit access to the coupling ACCESSORIES A. Variable Speed Drives: Variable speed drives shall be provided when called for on Schedule and shall be of the type specified in Section Variable Frequency Motor Controllers SOURCE QUALITY CONTROL A. Shop Tests: Prior to shipment, each pump shall be fully tested on water at the manufacturer's plant. The purpose of the shop tests shall be to demonstrate that the pumps to be provided shall meet the requirements of the Specifications and, if applicable, the Special Warranties included in the Agreement. 1. Tests shall consist of running the pumps with furnished impeller at their rated capacity, head, and speed, or range of speeds if furnished with variable speed drives, and at such other conditions of head and capacity to properly establish a performance curve or family of curves in the case of variable speed units. Performance data including efficiency and horsepower shall be collected and noted as part of the performance curve. 2. All pumps shall be tested in accordance with the standards of the Hydraulic Institute. Certified copies of the test results and the performance curves, for each of the pumps to be furnished, shall be submitted to ENGINEER and approved prior to shipment of the pumps to the Project. 3. Generally, pumps shall be tested as a complete assembly including drive and motor. If the pumps are tested separately from the motors, or variable speed drives and motors, CONTRACTOR shall submit to ENGINEER, certified performance curves of the equipment to be furnished as guaranteed by the manufacturer. These certified curves shall be obtained either from actual tests of the equipment to be furnished or from tests of equipment of the same size and construction. The motor manufacturer's curves shall supply all the necessary information concerning the equipment as indicated for the complete shop tests. 4. When pumps are tested separately from the variable speed drives, CONTRACTOR shall test one of each size drive complete with the actual motor to be furnished. Each drive and motor shall be tested at the specific speeds, torques, and power requirements for the duty point conditions required for any performance guarantee provisions of the Contract. PART 3 - EXECUTION 3.01 ERECTION A. Equipment provided under this Section shall be fabricated, assembled, erected, and placed in proper operation condition in full conformity with detail drawings, specifications, engineering data, instructions, and recommendations of the equipment manufacturer approved by ENGINEER FIELD QUALITY CONTROL A. Performance Tests: CNG F

12 1. After the pumping units have been erected, performance tests shall be conducted. The purpose of these performance tests shall be to demonstrate that the units have been properly erected, and that they and their appurtenant equipment will operate satisfactorily and meet the specified conditions and the guarantees of CONTRACTOR. 2. For the purpose of these tests, OWNER will furnish the electricity, lubricating oil, and the water for a test load when these items are available. The measurement of the quantity of water pumped may or may not be included in the performance test. 3. The performance tests shall be conducted under the supervision of ENGINEER with the cooperation of the manufacturer's factory representative. 4. It is intended that these tests shall be carried out by operating each pumping unit through the range specified for a continuous period of at least 2 hours, or until it is shown to the satisfaction of ENGINEER that all of the equipment is in perfect condition and will meet the requirements specified. Throughout these tests of the pumping equipment, the motors and pumps must run smoothly without vibration or heating, otherwise the test shall be stopped and not again undertaken until the unit shall have been put into condition to comply with the requirements for smoothness of operation. B. Installation Check: The manufacturer shall provide the services of a factory-trained representative to check the installation of all equipment installed in this Section. The services shall be as noted in Section Product Requirements TESTING AND TRAINING A. Operator Training: The station manufacturer shall furnish, in addition to the performance tests, operator training for 2 of OWNER's personnel. The training programs shall be conducted at the Site and shall be for a period of approximately 1 day. Training shall include, but not be limited to, operation safety, emergency, maintenance of equipment, and testing procedures CNG F

13 CENTRIFUGAL SEWAGE PUMP SCHEDULE No. of Units: 1 3 Type: Dry Pit Centrifugal Dry Pit Centrifugal Location: Chapman Street PS Chapman Street PS Service: Raw Sewage Raw Sewage Installation (Horizontal or Vertical): Vertical Vertical Capacity (gpm): Total Head (feet): Minimum NPSH at Duty Point: Minimum Shutoff Head: 75 feet 72 feet Maximum Pump Speed: 1800 rpm 1200 rpm Motor: Volt: Phase: 3 3 Enclosure: TEFC TEFC Accessories: Provide variable speed drive for each pump meeting requirements of specification Section Variable Frequency Motor Controllers. Remarks: Design intent is to replace the existing pumps in kind, without piping modifications. Other pumps may be proposed by Contractor, however, all piping and valve modifications, bypass pumping if required, is the responsibility of Contractor at no additional cost to Owner. END OF SECTION CNG F

14 Section Boiler and Heat Exchanger Part 1 General 1.01 Scope of Work A. Work under this section includes, but is not limited to the removal of the existing boiler and heat exchange unit and all related components, furnishing and installing a new combination boiler and heat exchanger as indicated on the project drawings, herein specified, as necessary for proper and complete performance. Each unit shall include a packaged combination of a fire tube boiler and a concentric tube heat exchanger, both so arranged that there is no transmission of heat from the boiler water to the tube jacket water by conduction or thermal circulation between sludge heating cycles. Each unit shall be designed to permit operation of the boiler at a temperature of not less than 180 F. A hot water circulation pump, with manual and automatic controls, shall be provided with each unit to circulate water through the water jackets during the heating period. The boiler and heat exchanger shall be rated for a nominal 250,000 BTU/hour Related Work Specified Elsewhere A. Unit Prices: Section B. Concrete: Division 03 C. Electrical: Section Reference Standards A. Unless otherwise specified, the Work of this Section shall conform to the applicable portions of the following Standard Specifications: 1.04 Submittals 1. ANSI - American National Standards Institute 2. ASTM - ASTM International 3. ASME Code Rules American Society of Mechanical Engineers 4. NEC National Electrical Code 5. NFPA 54, National Fuel Gas Code 6. UL Compliance: Comply with applicable requirements of UL 486A and B, and UL 508, 7. NEMA Compliance: Comply with applicable requirements of NEMA Standards ICS 2, "Industrial Control Devices, Controllers and Assemblies," and Pub No. 250 A. Submit Shop Drawings per section and this section, submittals shall include: 1. Shop Drawings: Submit Shop Drawings of motor controllers showing wiring diagrams, dimensions and sizes. 2. Product Data: Submit manufacturer's data and installation instructions on motor controllers CNG F

15 3. Wiring Diagrams: Submit power and control wiring diagrams for motor controllers 4. Submit operation and maintenance manuals for all components. Submit electronic copies on CD, as well as three hard cover copies. B. Operations and Maintenance Manuals 1. Operation shall be in accordance with written instructions provided by the manufacturer. Comprehensive instructions supplied at time of shipment shall enable personnel to properly operate and maintain all equipment supplied. Content and instructions shall assume operating personnel are familiar with pumps, motors, piping and valves, but lack experience on exact equipment supplied. 2. Documentation shall be specific to all equipment supplied and collated in functional sections. Each section shall combine to form a complete system manual covering all aspects of equipment supplied by the manufacturer. Support data for any equipment supplied by others, even if mounted or included in overall station design, shall be provided by those supplying the equipment. Instructions shall include the following as a minimum: a. Functional description of each major component, complete with operating instructions. b. Instructions for operating all controls in all modes of operation. c. Calibration and adjustment of equipment for initial start-up, replacement of necessary components, or as required for routine maintenance. d. Support data for commercially available components not produced by the manufacturer, but supplied in accordance with the specifications, shall be supported by literature from the manufacturer and incorporated as appendices. e. Electrical schematic diagram of all circuits shall be in accordance with NFPA 70. f. Schematics shall illustrate, to the extent of authorized repair, motor branch, control and alarm system circuits including interconnections. Wire numbers and legend symbols shall be shown. Schematic diagrams for individual components, not normally repairable by the operator, need not be included. Details for such parts shall not be substituted for an overall system schematic. Partial schematics block diagrams, and simplified schematics shall not be provided in lieu of an overall system diagram. g. Mechanical layout drawing of all components, prepared in accordance with good commercial practice, shall provide installation dimensions and location CNG F

16 C. Operation and maintenance instructions which rely on vendor cut-sheets and literature which include general configurations, or require operating personnel to selectively read portions of the manual shall not be acceptable. Operation and maintenance instructions must be specific to equipment supplied in accordance with these specifications Delivery of Materials A. Each unit shall be completely shop assembled, and then test fired prior to delivery Quality Assurance A. Manufacturer s Experience B. Testing 1. All equipment shall be furnished by manufacturers with at least ten (15) years experience in the manufacture and design of combination boiler and heat exchanger systems and components as specified. 2. Manufacture shall have at least twenty five (25) successfully operating installations in actual service for a period of not less than ten (10) years. Engineer may require evidence of this data. 3. Manufacturer shall be ISO 9001 certified. 1. The boiler and heat exchanger of each unit shall be hydrostatically tested in the shop to a pressure of 60 PSIG after the unit has been assembled. In addition, each unit shall be test fired in the shop and all control circuits thoroughly checked for satisfactory operation before the unit is shipped. Part 2 Products 2.01 Acceptable Manufacturers A. Walker Process Equipment, Lakeside Equipment, or Equal Equipment A. Boiler 1. Each unit shall include a fire tube boiler designed in accordance with ASME Rules for Construction - Low Pressure Boilers, and shall be rated at not less than 30 PSIG. The fire tubes in each boiler shall be No. 13 gauge boiler tubing having a minimum wall thickness of 0.095". The tubes shall be rolled and beaded into tube sheets having a minimum thickness of 3/8". The furnace of each boiler shall be fabricated from seamless steel boiler tubing of suitable diameter, electrically welded between the tube sheets, and fitted with refractory on the burner end to protect the burner parts and to promote efficient combustion. 2. Both the head and back plates of the boiler shall be accessible and readily removable for inspection without need for draining the boiler. The back plate of each boiler shall be fitted with a sight port for visually checking the flame CNG F

17 Each boiler shall be wrapped with a minimum of 1 1/2" of glass wool blanket insulation and enclosed with No. 14 gauge steel paneling. Each boiler shall be fitted with a low water cut-off, an ASME-rated pressure relief valve, a compression tank with water level gauge, a makeup water regulator, a thermometer, and pressure gauge. (Each boiler shall be supplied with 2" NPT connections to permit connecting the building heat supply and return piping.) 3. The boiler shell shall be shop surface prepared to SSPC-SP-10, and coated with a high performance industrial heat resistant coating such as Flame Control No. 888 by Flame Control Coatings, LLC or equivalent. All other fabricated steel parts shall be commercially cleaned per SSPC-SP-7, given one (1) shop coat of rust-inhibitive primer and one (1) shop coat of the Manufacturer's standard machinery enamel. 4. A Manufacturer's Data Report for Boilers, Form H-2, as required by the provisions of the ASME Code Rules, shall be furnished to the contractor for transmittal to the Owner. This form must be signed by a qualified inspector, holding a National Board commission, certifying that construction conforms to the latest revision of the ASME Code. B. Boiler Burner 1. The burner furnished with each boiler shall be of the forced draft design with only combustion air being furnished to the burner by a high-pressure air blower. Induced draft fans shall not be used since they must handle excess volumes of gas, are subject to attack from corrosive stack gases, and handle variable gas volumes and densities making it difficult to control air-fuel ratios for efficient combustion. Each burner shall efficiently burn digester (sludge) gas and natural gas. 2. Each burner shall be provided with the following controls (choose one): a. Digester Gas - Natural Gas Automatic Blend-in: Each burner shall be provided with all automatic controls required for the burning of either digester gas, natural gas, or a blend of the two gases. Upon depletion of the available digester gas, the auxiliary supply of natural gas shall be automatically admitted to the burner to make up the gas deficiency until sufficient digester gas is once again available. All available digester gas shall be fully utilized. In addition, each burner shall be supplied with a sensitive gas pressure regulator for each gas supply, a low-pressure check valve for the digester gas line and an adjustable gas orifice valve for the natural gas line. Threaded connections for gas supply piping shall also be supplied. 3. The control system for each burner shall provide a 30-second pre-purge before any starting cycle, after a power failure, and at fuel switchover. A substantial pilot must be established in the burner before admission of gas supply to the burner. Included with each burner shall be a control panel containing all burner controls, blower motor relay, timers and other appurtenances, all of which shall be mounted on the boiler body, and completely wired to the necessary remote controls and valves through a numbered terminal block furnished with the panel CNG F

18 4. Positive control of the fuel supply shall be maintained by employing an ultraviolet flame scanner solid-state flame protection device. The flame protection devices shall be Underwriters Laboratories and Factory Mutual approved. In the event of flame failure, the fuel supply valve shall be positively closed and an alarm sounded. 5. All electric gas valves shall be motorized and of a type approved by Underwriters Laboratories and American Gas Association. C. Heat Exchanger 1. The heat exchanger of each unit shall consist of a series of Schedule 40 steel pipe sludge tubes concentrically placed within Schedule 40 steel pipe water jackets. The tubes shall be joined by Neoprene-gasketed end castings so designed that any leakage occurring will be to the exterior of the heat exchanger. The tubes shall be supported by 3/4" thick steel end plates with structural steel members serving as boiler supports and framing for the exterior steel paneling. The sludge and water tubes shall be independently removable and so arranged as to prevent contamination of the heating water by material circulated through the sludge tubes. 2. The sludge tube end castings shall be removable to permit tube inspection without having to drain the jacket water. All sludge passageways shall be designed to pass (3") spheres. The inlet and outlet connections shall be of cast iron and shall have 4" flange connections for sludge piping and threaded connections for jacket water piping. In addition, these castings shall have 3/4" NPT connections for attachment of sludge and water inlet and outlet thermometers. The entire sludge-water tube bundle shall be wrapped independently of the boiler with a minimum of 1 1/2" of blanket insulation. 3. The heat exchanger of each unit shall have sludge tubes that will provide a total heated surface area, measured on the inside of the sludge tubes, of not less than 28.9 SQ. FT. 4. A Manufacturer's Data Report for Unfired Pressure Vessels, Form U-1, as required by the provisions of the ASME Code Rules, shall be furnished to the contractor for transmittal to the Owner. This form must be signed by a qualified inspector, holding a National Board commission, certifying that construction conforms to the latest revision of the ASME Code. The ASME "U" symbol shall also be stamped on the heat exchanger nameplate. D. Hot Water Circulation Pump 1. Each unit shall be provided with a centrifugal pump to provide positive, counter flow circulation of hot water through the water jackets. 2. The pump shall be factory-mounted in an accessible part of the unit and shall be driven by a minimum 1 HP motor. E. Circulating Water Control Valve CNG F

19 1. Each unit shall be provided with a thermostatic limit valve placed in the water jacket circulating line to maintain a boiler water temperature of 180 F, regardless of the load on the boiler, so that a sufficient supply of heat will always be available for sludge heating and, also, to prevent condensate corrosion of the boiler. Boilers operating at temperatures under 180 F will not be allowed due to potential corrosion problems. The control valve shall also limit the sludge heat exchanger jacket water from exceeding a temperature of 150 F to prevent sludge "baking" on the tubes and the resultant loss of heat transfer efficiency. F. Digester Temperature Control 1. The system for controlling the temperature of the digester contents within the desired limits shall include the following controls (choose one): a. Manual control - The digester temperature control shall be provided by manual operation of "On-Off" selector switches for the starters controlling the sludge recirculation pump and the hot water circulation pump. All operating controls shall be in an enclosed control panel mounted on the boiler and wired to a numbered terminal block. Each unit shall be provided with factory-installed water and sludge indicating thermometers mounted in the inlet and outlet castings of the heat exchanger. All four thermometers shall be the mercury red reading type having a range of F. b. Timed-Automatic Control - (When automatic control of the contents of the digester is desired, it is suggested that this system be used rather than the system outlined in 1 above.) The automatic control of the temperature of the digester contents within 0.5 F, plus or minus, shall be accomplished by means of a temperature controller with a thermocouple inserted in the sludge inlet casting on each heat exchanger. An adjustable program timer shall be furnished to periodically start the sludge recirculation and hot water circulation pumps. The controls shall be so arranged that the pumps will continue in operation until the temperature of the digester contents has reached the desired level or, if the digester contents do not require heat, the pumps will be shut down after a short period of operation. The hot water circulation pump starter shall be interlocked with the sludge recirculation pump starter so that the sludge recirculation pump must be operating before the hot water circulation pump can operate when the control cycle is on automatic. The control cycle shall also be arranged so that, if desired, the sludge recirculation pump can operate continuously, under manual control, with the temperature controller operating the hot water circulation pump only as required to maintain the temperature of the digester contents. 2. The sludge recirculation pump starter shall be interlocked with the raw sludge pump starter to insure operation of the sludge recirculation pump when raw sludge is pumped to the digester through the heat exchanger. 3. All operating controls, except the thermocouple and the sludge recirculation pump starter, shall be in an enclosed control panel mounted on the boiler and wired to a numbered terminal block. Each unit shall be provided with factoryinstalled water and sludge thermometers mounted in the inlet and outlet castings of the sludge heat exchanger CNG F

20 G. Motor Characteristics All four thermometers shall be of the mercury red reading type with a range of F for water and F for sludge. 1. Each motor shall be NEMA Design B, open drip proof with Class B insulation, and shall include a sealed conduit box. H. Guarantee 1. The equipment manufacturer shall guarantee the equipment against defect in design, material and workmanship for a period of twelve (12) months after initial operation of the equipment in accordance with the General Conditions. Part 3 Execution 3.01 Installation A. Install all equipment in accordance with the manufacturer s instructions, recommendations, and approved shop drawings. B. Pumps 1. The sludge recirculation pump shall be furnished by the contractor under Specification Section and installed by the contractor at the location shown on the Plans. Each sludge recirculation pump shall be as described in Specification Section and shall have a capacity of 300 GPM at 26 feet total dynamic head. This head includes sludge side friction headloss through the heat exchanger and the friction headloss in the sludge pipework. C. All piping of each unit shall be shop fabricated and assembled. All other piping to and from the unit shall be furnished and installed by the contractor. D. The equipment manufacturer shall furnish all Type 304 stainless steel anchor bolts, nuts washers and gaskets necessary for the equipment furnished by him, as well as any templates required for setting the anchorage. E. The contractor shall furnish and apply all touch-up of the finish paint coats in accordance with the requirements of Part Manufacturers Services End of Section A. Furnish the services of a qualified manufacturer s representative to inspect the complete installation, make any necessary adjustments, participate in the startup and field testing of equipment, and place into operation. B. Furnish the services of a qualified manufacturer s representative to instruct plant personnel in the operation and maintenance of equipment. C. The following manufacturer s service shall be provided. 1. One (1) trip for one (1) eight hour days for startup. 2. One (1) trip for one (1) eight hour day for operator training in operation and maintenance of the systems CNG F