223500 DOMESTIC WATER HEAT EXCHANGERS.pdf

Bid Addendum #1 BATTLE CREEK VA MEDICAL CENTER

RENOVATE AUDIOLOGY

PROJECT NO. 515-23-101

09-01-20

DOMESTIC WATER HEAT EXCHANGERS

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SECTION 22 35 00

PART 1 - GENERAL

1.1 DESCRIPTION

A. This section describes the requirements for domestic hot water heat exchangers including thermometers and all necessary accessories, connections and equipment.

B. Application is for indirect water heating utilizing steam or hot water as a medium and can be used for heat recovery or solar systems for pre-heating water prior to primary water heating equipment.

C. A complete listing of common acronyms and abbreviations are included in

Section 22 05 11, COMMON WORK RESULTS FOR PLUMBING.

1.2 RELATED WORK

A. Section 01 00 00, GENERAL REQUIREMENTS.

B. Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, AND SAMPLES.

C. Section 01 91 00, GENERAL COMMISSIONING REQUIREMENTS.

D. Section 22 05 11, COMMON WORK RESULTS FOR PLUMBING.

E. Section 22 05 19, METERS AND GAGES FOR PLUMBING PIPING.

F. Section 22 05 23, GENERAL-DUTY VALVES FOR PLUMBING PIPING.

G. Section 22 08 00, COMMISSIONING OF PLUMBING SYSTEMS.

H. Section 22 11 23, DOMESTIC WATER PUMPS: Circulating Pump.

1.3 APPLICABLE PUBLICATIONS

A. The publications listed below form a part of this specification to the extent referenced. The publications are referenced in the text by the basic designation only. Where conflicts occur these specifications and the VHA standards will govern.

B. American Society of Heating, Refrigerating and Air-Conditioning

Engineers (ASHRAE):

90.1-2019...............Energy Standard for Buildings Except Low-Rise

Residential Buildings

C. American National Standard Institute (ANSI):

Z21.22-2015.............Relief Valves for Hot Water Supply Systems

D. American Society of Mechanical Engineers (ASME):

ASME Boiler and Pressure Vessel Code –

BPVC Section IV-2019....Rules for Construction of Heating Boilers

BPVC Section VIII-1-2019 Rules for Construction of Pressure

Vessels, Division 1

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Form U-1................Manufacturer’s Data Report for Pressure Vessels

B1.20.1-2013............Pipe Threads, General Purpose (Inch)

B16.5-2017..............Pipe Flanges and Flanged Fittings: NPS 1/2 through NPS 24 Metric/Inch Standard

B16.24-2016.............Cast Copper Alloy Pipe Flanges, Flanged

Fittings, and Valves: Classes 150, 300, 600, 900, 1500, and 2500

PTC 25-2018.............Pressure Relief Devices

E. National Fire Protection Association (NFPA):

70-2020.................National Electrical Code (NEC)

F. NSF International (NSF):

61-2018.................Drinking Water System Components – Health

Effects

372-2016................Drinking Water System Components – Lead Content

G. Underwriter Laboratories (UL):

207-2009(R2020).........Standard for Refrigerant-Containing Components and Accessories, Nonelectrical

778-2016(R2019).........Standard for Motor-Operated Water Pumps

1.4 SUBMITTALS

A. Submittals, including number of required copies, shall be submitted in accordance with Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, and

SAMPLES.

B. Information and material submitted under this section shall be marked

“SUBMITTED UNDER SECTION 22 35 00, DOMESTIC WATER HEAT EXCHANGERS”,

with applicable paragraph identification.

C. Manufacturer's Literature and Data Including: Full item description and optional features and accessories. Include dimensions, weights, materials, applications, standard compliance, model numbers, size, and capacity.

1. Heat Exchangers.

2. Heat Reclaimers.

3. Pressure and Temperature Relief Valves.

4. Steam Control Valves.

5. Heating Hot Water Control Valves.

6. Thermometers.

7. Pressure Gauges.

8. Vacuum Breakers.

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9. Safety Valves.

10. Expansion Tanks.

11. Circulating Pumps.

12. Steam Traps.

13. Heat Traps.

D. A Form U-1 or other documentation stating compliance with the ASME

Boiler and Pressure Vessel Code.

E. Shop drawings shall include wiring diagrams for power, signal and control functions.

F. Complete operating and maintenance manuals including wiring diagrams, technical data sheets, information for ordering replaceable parts, and troubleshooting guide:

1. Include complete list indicating all components of the systems.

2. Include complete diagrams of the internal wiring for each item of equipment.

3. Diagrams shall have their terminals identified to facilitate installation, operation and maintenance.

G. Completed System Readiness Checklist provided by the CxA and completed by the contractor, signed by a qualified technician and dated on the date of completion, in accordance with the requirements of Section 22

08 00, COMMISSIONING OF PLUMBING SYSTEMS.

H. Submit training plans and instructor qualifications in accordance with the requirements of Section 22 08 00, COMMISSIONING OF PLUMBING

SYSTEMS.

1.5 QUALITY ASSURANCE

A. Equipment components in contact with potable water shall meet compliance requirements in documents NSF 61 and NSF 372.

B. Comply with American Society of Heating, Refrigerating and Air-

Conditioning Engineers (ASHRAE) 90.1 for efficiency performance.

C. The heat exchanger shall be certified and labeled by an independent testing agency.

D. Circulating pump power shall be installed per NFPA 70.

E. Bio-Based Materials: For products designated by the USDA’s

Bio-Preferred Program, provide products that meet or exceed USDA recommendations for bio-based content, so long as products meet all performance requirements in this specifications section. For more

22 35 00 - 4 information regarding the product categories covered by the

Bio-Preferred Program, visit https://www.biopreferred.gov.

1.6 AS-BUILT DOCUMENTATION

A. Comply with requirements in Paragraph AS-BUILT DOCUMENTATION of Section

22 05 11, COMMON WORK RESULTS FOR PLUMBING.

PART 2 - PRODUCTS

2.1 SHELL AND TUBE, DOMESTIC WATER HEAT EXCHANGERS

A. The shell and tube heat exchangers shall be double wall, semi-instantaneous type, horizontal configuration with domestic water in the tubes and steam in the shell. Heat exchanger shall be of counter-flow design. The shell and tube heat exchanger shall be a packaged assembly of tank, heat exchanger coils, control valves, controls, and specialties constructed of ASME code stainless steel shell with 1034 kPa (150 psig) minimum working pressure. Heat exchanger shall comply with NSF 61 and NSF 372 for barrier materials for potable-water tank linings. Provide with access for cleaning and disinfection. Heat exchanger capacities are scheduled on the drawings.

B. The stand or skid shall be factory-fabricated for floor mounting. It shall be a split stand for ease of disassembly and movement through the building.

C. The tappings (openings) shall be factory-fabricated of materials compatible with the tank and in accordance with appropriate ASME standards for piping connections, pressure and temperature relief valve or another approved method of pressure and temperature relief, pressure gauge, thermometer, drain valve, anode rods and controls. The openings shall be in accordance with ASME standards listed below:

1. 50 mm or DN50 (NPS 2 inch) and smaller: Threaded ends according to

ASME B1.20.1.

2. 65 mm or DN65 (NPS 2-1/2 inch) and larger: Flanged ends according to

ASME B16.5 for steel and stainless-steel flanges, and according to

ASME B16.24.

D. Shell insulation shall comply with ASHRAE 90.1 and suitable for operating temperature. The entire shell and nozzles shall be completely surrounded except connections, gauges and controls.

E. The heat exchanger coils shall be constructed from copper and fabricated in a helix wound or straight tube configuration for steam

22 35 00 - 5 heating medium. The pressure rating shall be equal to or greater than the steam supply pressure plus 50 percent.

F. The temperature controls shall be designed for an output temperature of

60 degrees C (140 degrees F) based upon an adjustable temperature transmitter that operates a control valve and is capable of maintaining outlet water temperature within 2 degrees C (4 degrees F) of setting.

Heaters shall be capable of raising the discharge temperature to 77 to

82 degrees C (170 to 180 degrees F) for thermal eradication.

1. Steam control valve shall regulate the control of steam flow to the heating coil to control water temperature and shall be electronically operated. Alternatively, the control valve can utilize constant pressure steam monitored by the control valve. The outlet water temperature shall not vary more than +/- 1 degrees C

(2.5 degrees F).

2. A drip trap, steam condensate trap (if required), Y strainer, vacuum breaker, and pressure gauge shall be factory sized and piped with steam control valve per manufacturer’s instructions.

3. A normally closed solenoid valve shall be rated at 5 amps, 120-volt.

Solenoid valve shall close the steam supply to the heating coil, should the water temperature in the tank reach the high set point.

G. Safety control shall be automatic, high temperature limit shutoff device or another approved safety control scheme.

H. The relief valves shall be ASME rated and stamped for combination temperature and pressure relief valves or another approved method of pressure and temperature relief.

I. The pressure storage vessel shall be all welded construction and ASME

BPVC Section VIII-1 stamped for a working pressure of 1034 kPa (150 psig). The shell of the exchanger shall be carbon steel. Lining shall meet NSF 61 and NSF 372 requirements. The storage vessel shall be provided with a fiberglass insulation system in compliance with ASHRAE

90.1, with jacket, and a magnesium anode. Provide with access for cleaning and disinfection.

2.2 THERMOMETERS

A. Thermometers shall be rigid stem or remote sensing, scale or dial type with an aluminum, black metal, stainless-steel, or chromium plated brass case. The thermometer shall be back connected, red liquid

(alcohol or organic-based) fill, vapor, bi-metal or gas actuated, with

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228 mm (9 inches) high scale dial or circular dial 50 to 127 mm (2 to 5 inches) in diameter graduated from 4 to 100 degrees C (40 to 212 degrees F), with two-degree graduations guaranteed accurate within one scale division. The socket shall be separable, double-seat, micrometer-fittings, with extension neck not less than 63 mm (2 1/2 inches) to clear tank or pipe covering. The thermometer shall be suitable for 19 mm (3/4 inch) pipe threads. Thermometers may be console-mounted with sensor installed in separate thermometer well.

2.3 SAFETY VALVES FOR SHELL AND COIL HEATERS

A. Separate combination pressure/temperature relief valves shall be provided on each water heater or another approved method of pressure and temperature relief.

B. A double solenoid safety system shall be provided for each shell and coil heater to function as a safety over temperature prevention system.

System shall consist of aquastat, pilot light, solenoid safety valve and solenoid water safety valve located in the control circuit. The aquastat shall be set at 60 degrees C (140 degrees F). Alternatively, if the temperature reaches the maximum temperature, the automated valve on the hot outlet of the exchanger will close and move the mixing valve to the cold position. This shall require a manual reset to inspect for maintenance issues. Shutoff valves shall comply with Section 22 05 23, GENERAL-DUTY VALVES FOR PLUMBING PIPING.

2.4 DOMESTIC HOT WATER EXPANSION TANKS

A. A steel pressure rated tank constructed with welded joints and factory installed butyl rubber diaphragm shall be installed as scheduled. The air precharge shall be set to minimum system operating pressure at tank.

B. The tappings shall be factory-fabricated steel, welded to the tank and include ASME B1.20.1 pipe thread.

C. The interior finish shall comply with NSF 61 and NSF 372 for barrier materials for potable water tank linings and the liner shall extend into and through the tank fittings and outlets.

D. The air charging valve shall be factory installed.

2.5 HEAT TRAPS

A. Heat traps shall be installed in accordance with ASHRAE 90.1 unless provided integrally with the heaters.

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2.6 COMBINATION TEMPERATURE AND PRESSURE RELIEF VALVES

A. The combination pressure and temperature relief Valve shall be ANSI

Z21.22 and ASME rated and constructed of all brass or bronze with a self-closing reseating valve. The relief valves shall include a relieving capacity greater than the heat input and include a pressure setting less than the water heater’s working pressure rating. Sensing element shall extend into storage tank.

PART 3 - EXECUTION

3.1 INSTALLATION

A. If an installation is unsatisfactory to the COR, the contractor shall correct the installation at no additional cost or time to the

Government.

B. The water heaters shall be installed on concrete bases. Refer to

Section 22 05 11, COMMON WORK RESULTS FOR PLUMBING.

C. The water heaters shall be installed level and plumb and securely anchored.

D. Water heaters shall be installed and connected in accordance with manufacturer’s written instructions with manufacturer’s recommended clearances.

E. All pressure and temperature relief valves discharge shall be piped to nearby floor drains with air gap or break.

F. Thermometers and isolation valves shall be installed on water heater inlet and outlet piping and shall be positioned such that they can be read by an operator or staff standing on floor or walkway.

G. Shutoff valves shall be installed on the domestic water supply piping to the water heater and on the domestic hot water outlet piping.

H. All manufacturer’s required clearances shall be maintained.

I. A combination temperature and pressure relief valve shall be installed at the top portion of the storage tank. The sensing element shall extend into the tank. The relief valve outlet drain piping shall discharge by air gap into a floor drain.

J. Water heater drain piping shall be installed as indirect waste to spill by air gap into open drains or over floor drains.

K. Dielectric unions shall be provided if there are dissimilar metals between the water heater connections and the attached piping.

L. Provide vacuum breakers per ANSI Z21.22 on the inlet pipe if the water heater is bottom fed.

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3.2 LEAKAGE TEST

A. Before piping connections are made, the water heaters shall be tested at a hydrostatic pressure of 1380 kPa (200 psig) for water heaters rated at less than 1104 kPa (160 psig) and 1654 kPa (240 psig) for units with an maximum working pressure of 1104 kPa (160 psig) or over.

Any failed test shall be corrected and the water heater shall be replaced with a new unit at no additional cost or time to the

Government.

3.3 PERFORMANCE TEST

A. Ensure that all the remote water outlets are always tested to a minimum of 43 degrees C (110 degrees F) and a maximum of 49 degrees C (120 degrees F) water flow. If necessary, make all correction to balance the return water system or reset the thermostat to make the system comply with design requirements.

3.4 STARTUP AND TESTING

A. Perform tests as recommended by product manufacturer and listed standards and under actual or simulated operating conditions and prove full compliance with design and specified requirements. Tests of the various items of equipment shall be performed simultaneously with the system of which each item is an integral part.

B. The tests shall include system capacity, control function, and alarm functions.

C. When any defects are detected, correct defects and repeat test at no additional cost or time to the Government.

D. The CxA will observe startup and contractor testing of selected equipment. Coordinate the startup and contractor testing schedules with the COR and CxA. Provide a minimum notice of 10 working days prior to startup and testing.

3.5 COMMISSIONING

A. Provide commissioning documentation in accordance with the requirements of Section 22 08 00, COMMISSIONING OF PLUMBING SYSTEMS.

B. Components provided under this section of the specification will be tested as part of a larger system.

3.6 DEMONSTRATION AND TRAINING

A. Provide services of manufacturer’s technical representative for 4 hours to instruct each VA Personnel responsible in operation and maintenance of the system.

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B. Submit training plans and instructor qualifications in accordance with the requirements of Section 22 08 00, COMMISSIONING OF PLUMBING

SYSTEMS.

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