36C26118B0377-022.pdf

VETERANS AFFAIRS NORTHERN CALIFORNIA HEALTH CARE SYSTEM

Consolidated CHW/HW Piping

Project No. 612A4-18-233

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SECTION 23 25 00

HVAC WATER TREATMENT

PART 1 - GENERAL

1.1 DESCRIPTION

A. This section specifies cleaning and treatment of circulating HVAC water systems, including the following.

1. Cleaning compounds.

2. Chemical treatment for closed loop heat transfer systems.

3. Chemical treatment for open loop systems.

4.

1.2 RELATED WORK

A. Section 01 00 00, GENERAL REQUIREMENTS.

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

C. Section 23 05 11, COMMON WORK RESULTS FOR HVAC and STEAM GENERATION.

D. Section 23 21 13, HYDRONIC PIPING.

1.3 QUALITY ASSURANCE

A. Refer to paragraph, QUALITY ASSURANCE in Section 23 05 11, COMMON WORK

RESULTS FOR HVAC and STEAM GENERATION.

B. Technical Services: Provide the services of an experienced water treatment chemical engineer or technical representative to direct flushing, cleaning, pre-treatment, training, debugging, and acceptance testing operations; direct and perform chemical limit control during construction period and monitor systems for a period of 12 months after acceptance, including not less than 6 service calls and written status reports. Emergency calls are not included. //During this period perform monthly tests of the cooling tower for Legionella pneumophila and submit reports stating Legionella bacteria count per millimeter. These tests shall be conducted in a certified laboratory and not by a technician in the field. Minimum service during construction/start-up shall be 6 hours.

C. Field Quality Control and Certified Laboratory Reports: During the one year guarantee period, the water treatment laboratory shall provide not less than 12 reports based on on-site periodic visits, as stated in paragraph 1.3.B, sample taking and testing, and review with VA

23 25 00 - 2 personnel, of water treatment control for the previous period. In addition to field tests, the water treatment laboratory shall provide certified laboratory test reports. These monitoring reports shall assess chemical treatment accuracy, scale formation, fouling and corrosion control, and shall contain instructions for the correction of any out-of-control condition.

D. Log Forms: Provide one year supply of preprinted water treatment test log forms.

E. Chemicals: Chemicals shall be non-toxic approved by local authorities and meeting applicable EPA requirements.

1.4 SUBMITTALS

A. Submit in accordance with Section 01 33 23, SHOP DRAWINGS, PRODUCT

DATA, and SAMPLES.

B. Manufacturer's Literature and Data including:

1. Cleaning compounds and recommended procedures for their use.

2. Chemical treatment for closed systems, including installation and operating instructions.

3. Chemical treatment for open loop systems, including installation and operating instructions.

4. Glycol-water system materials, equipment, and installation.

C. Water analysis verification.

D. Materials Safety Data Sheet for all proposed chemical compounds, based on U.S. Department of Labor Form No. L5B-005-4.

E. Maintenance and operating instructions in accordance with Section

01 00 00, GENERAL REQUIREMENTS.

1.5 APPLICABLE PUBLICATIONS

A. The publication listed below form a part of this specification to the extent referenced. The publications are referenced in the text by the basic designation only.

B. National Fire Protection Association (NFPA):

70-2008.................National Electric Code (NEC)

C. American Society for Testing and Materials (ASTM):

F441/F441M-02 (2008) ... Standard Specification for Chlorinated Poly

(Vinyl Chloride) (CPVC) Plastic Pipe, Schedules

40 and 80

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PART 2 - PRODUCTS

2.1 CLEANING COMPOUNDS

A. Alkaline phosphate or non-phosphate detergent/surfactant/specific to remove organic soil, hydrocarbons, flux, pipe mill varnish, pipe compounds, iron oxide, and like deleterious substances, with or without inhibitor, suitable for system wetted metals without deleterious effects.

B. All chemicals to be acceptable for discharge to sanitary sewer.

C. Refer to Section 23 21 13, HYDRONIC PIPING and Section 23 22 13, STEAM and CONDENSATE HEATING PIPING, PART 3, for flushing and cleaning procedures.

2.2 CHEMICAL TREATMENT FOR CLOSED LOOP SYSTEMS

A. Inhibitor: Provide sodium nitrite/borate, molybdate-based inhibitor or other approved compound suitable for make-up quality and make-up rate and which will cause or enhance bacteria/corrosion problems or mechanical seal failure due to excessive total dissolved solids. Shot feed manually. Maintain inhibitor residual as determined by water treatment laboratory, taking into consideration residual and temperature effect on pump mechanical seals.

B. pH Control: Inhibitor formulation shall include adequate buffer to maintain pH range of 8.0 to 10.5.

C. Performance: Protect various wetted, coupled, materials of construction including ferrous, and red and yellow metals. Maintain system essentially free of scale, corrosion, and fouling. Corrosion rate of following metals shall not exceed specified mills per year penetration;

ferrous, 0-2; brass, 0-1; copper, 0-1. Inhibitor shall be stable at equipment skin surface temperatures and bulk water temperatures of not less than 121 degrees C (250 degrees F) and 52 degrees C (125 degrees

Fahrenheit) respectively. Heat exchanger fouling and capacity reduction shall not exceed that allowed by fouling factor 0.0005.

D. Pot Feeder: By-pass type, complete with necessary shut off valves, drain and air release valves, and system connections, for introducing chemicals into system, cast iron or steel tank with funnel or large opening on top for easy chemical addition. Feeders shall be 18.9 L

(five gallon) minimum capacity at 860 kPa (125 psig) minimum working pressure.

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2.3 CHEMICAL TREATMENT FOR OPEN LOOP SYSTEM(S)

A. General: Provide the following:

1. A factory-fabricated and tested packaged, self-contained, chemical feed/blow-down monitoring, controlling and alarming system, containing all except specified or indicated remote components, and requiring only terminal sample stream and chemical piping/tubing connections, remote component electrical connection and power supply.

2. System shall be suitable for a broad spectrum make-up water supply and chemical treatment program. Components, except those specified or indicated otherwise, shall be housed in one or more joined or divided steel enclosures.

B. System Functions:

1. Automatically maintain a predetermined, selectable, total dissolved solids concentration through a continuously monitoring conductivity controller, maintain a predetermined, selectable, scale/corrosion inhibitor and dispersant residual, through a continuously make-up monitoring meter/counter/timer and inhibitor/dispersant ratio controller; achieve a predetermined, selectable, peak concentration of one or two microbiocides as needed on an alternating basis, through a programmable timer controller. De-energize controller or stagger feed chemicals that would degrade or could be incompatible if fed simultaneously.

2. Automatically maintain a predetermined, selectable, pH level through a continuously monitoring pH controller. For systems with make up water alkalinity in excess of 125 PPM or hardness above 300 PPM, provide acid feed limit timer and audible/visual alarm actuated on low pH.

C. Main control panel and accessories:

1. Housed in a NEMA Type 4X enclosure:

a. Hinged key lock door with viewing window.

b. Hard wire connected to power source.

c. Provide minimum of three (3) 115V, 1 Ph, 60 Hz receptacles located on enclosure for electrical connection and control of chemical pumps.

d. Prewired for ease of installation.

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2. Provide an external combination mounted flow switch with transparent sight tube.

a. Disable control outputs upon loss of water flow to prevent chemical feeding.

b. Provide complete with 3/4 IN connections and combination conductivity and temperature electrode.

3. Keypad or remote control: Access all measurements and set points through chemical resistant key pad or remote.

a. Security code to prevent unauthorized access.

4. Utilize microprocessor technology.

5. Menu driver programs.

6. Liquid crystal display (LCD).

7. Provide temperature corrected measurements by reading water temperature and adjusting conductivity values according to known temperature curve.

a. Range: 0-100 degC (32-212 degF) with an adjustable high alarm.

8. Provide real-time clock.

9. Conductivity monitor:

a. Provide linear measurements of full range.

b. Provide two scales for selection of high and low in field to assure accurate measurements.

c. Provide increments of 1 microohm/cm with adjustable hysteresis.

d. Provide bleed-off control in following manner:

1) Standard operation-controller actuates a bleed off solenoid valve when dissolved solids level is exceeded by trip point.

2) Provide an adjustable bleed limit timer to prevent excessive bleed off.

3) An alarm contact shall close when timer has timed out.

10. Biocide operation:

a. Provide a programmable 28 day biocide timer for accurate addition of algaecide.

b. Provide a secondary bleed off timer to lower conductivity in system prior to biocide feed.

c. Lock out cooling water bleed-off during biocide feed period.

11. Chemical feed control: Provide three timers that are capable of operating in one of following field programmable modes.

a. Counter-timer-chemical feed proportioned to make-up water rate.

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1) Controller shall send low voltage signal to a contacting head water meter.

2) Low voltage signal will ensure long contact life.

3) Water meter shall read in gallons.

12. Alarms:

a. Provide alarm LEDs with silence button for high and low conductivity, 10-60 minute bleed-off, chemical feed limit timers, and chemical drum level. Provide remote output relay to indicate alarm condition to Building Control System specified under

Section 23 09 23, DIRECT-DIGITAL CONTROL SYSTEM FOR HVAC.

13. Controller operating data history:

a. Retain in memory all operating data for following parameters:

1) Standard memory shall allow acquisition and storage of all analog inputs for a one-week period.

2) A three (3) hour minimum, maximum average of all conditions shall be stored for a one-week period.

3) A minute-by-minute account of operating conditions shall be available for latest three-hour period.

14. Electrode: Combination temperature and conductivity type.

a. Quick disconnect.

b. Supplied in flow switch assembly.

15. Ph monitor:

a. Sensor for monitoring purposes only.

b. Acid shall not be used to control pH.

16. Remote communication: Provide open protocol BACnet/IP interface to perform the following functions:

a. Access Real-time system values.

b. Change operating parameters.

c. Controller diagnostics.

d. Obtain history files.

e. Alarm condition notification.

D. Impulse water meter:

1. General:

a. Measure in gallons.

b. Sized to meter peak make up rates.

c. Equipped with an electrical contacting register.

d. Totalize flow at main control panel.

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2. Provide at following locations:

a. Cooling tower make up line.

b. Cooling tower bleed off line.

E. Provide CPVC injection nozzles, ASTM F441 with corporation stop to inject chemical into main circulating water line.

1. Pressure rating: 700kPa (100 PSI)

2. Size: DN20 (3/4 IN) NPT.

3. Quantity: Three (3).

F. Provide chemical feed pumps operated by a 115V, 60 cycle, single PH motor.

1. Provide separate stroke and stroke frequency setting capabilities.

2. Positive displacement type pump

a. Provide with anti-siphon/pressure relief valve installed on pump head which provides anti-siphon protection and aids in priming under pressure.

b. Capacity: As determined by Water Treatment Vendor.

c. Complete with discharge check valves, foot valves, polyethylene suction and discharge tubing.

3. Quantity: Provide one pump for each chemical provided.

G. Bleed-off piping assembly:

1. Inlet shut-off valve.

2. Wye strainer.

3. Strainer blowdown valve.

4. Throttling valve.

5. Brass solenoid valve compatible with main control panel.

6. Assembly shall be sized by Water Treatment Vendor.

H. Secondary containment spill pallets for chemical drums:

1. Material: Polyethylene.

2. Capacity: 250 L (66 GAL) each.

3. Dimensions each: DN135 (53 IN) length x DN74 (29 IN) wide X DN43

(17 IN) high.

4. Provide each pallet with grating and drain plug.

5. Provide one portable loading ramp.

6. Quantity: Two (2).

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I. Provide liquid level switch assemblies with a CPVC bung hole adapter, ASTM F441, to mount directly into 200 L (55 GAL) chemical drum bung hole.

1. Interface with main control panel.

2. Quantity: Three (3).

J. Corrosion monitor rack:

1. Materials: Corrosion resistant.

2. Construction: ASME specifications.

3. Number of coupons: four (4).

4. Coupon holders: quick disconnect type.

K. Provide test kits for monitoring inhibitor levels, total dissolved solids, chlorides, alkalinity and closed system inhibitors.

L. Erosion chemical feeder:

1. Completely enclosed.

2. Materials: Corrosion resistant.

3. External, non-clog inlet control valve.

4. Bottom drain valve.

5. Inlet and outlet connections to allow for recirculating water.

6. Suitable for use with chlorine or bromine tablets.

N. Chemicals: Except for acid, provide sufficient chemicals for start-up and testing and twelve months operation from date of project acceptance.

1. Scale/corrosion inhibitor: Provide a concentrated liquid organic corrosion/scale/ fouling inhibiting formation without phosphates, chromates, zinc and other materials in excess of allowable, local, effluent limits. Feed automatically. Maintain residual as determined by water treatment laboratory.

2. Dispersant: Provide a concentrated liquid organic/polyelectrolyte formulation. Feed automatically. Maintain residual as determined by water treatment laboratory.

3. pH Control: Depending upon local water conditions, provide 60 or 66 degree Baume technical grade, concentrated sulfuric acid for acidic treatment or sodium hydroxide (NaOH) for basic treatment to maintain pH in the range of 7.0 to 8.0 automatically. Provide one initial 47

L (12.5 gallon) carboy of acid or base and one spare carboy of acid or base, if required.

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4. Microbiocides: Provide two different, one oxidizing and one non-oxidizing, concentrated algaecide-biocide formations containing no heavy metals and which are effective at maximum encountered pH.

Alternate solutions as needed to effectuate selective kill without build-up of immunity. Period treatment with a chlorine releasing agent is permissible within allowable, local, effluent limits. Feed automatically. Develop peak concentration and maintain for minimum period as determined by water treatment laboratory.

5. All chemicals to be acceptable for discharge to sanitary sewer.

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