Specifications for Low Profile Series V Closed Circuit Cooling Towers

Detailed Series V Specification formatted for word processor use

1.0 Closed Circuit Cooling Tower

1.1 General: Furnish and install ____factory assembled, forced draft, centrifugal fan, closed circuit cooling tower(s) with vertical air discharge, conforming in all aspects to the specifications and schedules as shown on the plans. Overall dimensions shall not exceed approximately ____ft (mm) long x ____ft (mm) wide x ____ft (mm) high. The total connected fan horsepower shall not exceed ____HP (kW). The total connected pump horsepower shall not exceed ____HP (kW). The closed circuit cooling tower(s) shall be Baltimore Aircoil Company Model(s) ________________.

1.2 Thermal Capacity (water as heat transfer fluid): The closed-circuit cooling tower(s) shall be warranted by the manufacturer to cool ______USGPM (l/s) of _______ water from ____°F (°C) to ____°F (°C) at ____°F (°C) entering wet-bulb temperature. The thermal performance shall be certified by the Cooling Technology Institute in accordance with CTI Certification Standard STD-201. A manufacturer’s performance guarantee or performance bond without CTI Certification will not be accepted.

(Alternate) 1.2 Thermal Capacity (aqueous glycol solution as heat transfer fluid): The closed circuit cooling tower(s) shall cool ________USGPM (l/s) of _____% by volume ethylene/propylene glycol solution from ______°F (°C) to _____°F (°C) at _____°F (°C) entering wet-bulb temperature. Coil pressure drop shall not exceed ________ psi (kPa). Basis for thermal performance rating shall be the Cooling Technology Institute (CTI) certified rating for water cooling appropriately adjusted for the thermal properties of the aqueous glycol solution used. Additionally, the thermal performance of the product line with water as the heat transfer fluid shall be certified by the CTI in accordance with CTI Certification Standard STD-201. Manufacturers' performance guarantees or performance bonds without CTI Certification of water ratings shall not be accepted.

1.3 Corrosion Resistant Construction: Unless otherwise noted in this specification, all steel panels and structural members shall be constructed of heavy-gauge G-235 (Z700 metric) hot-dip galvanized steel, with all sheared edges given a protective coating of zinc-rich compound.

(Alternate) 1.3 Corrosion Resistant Construction: Unless otherwise noted in this specification, all steel panels and structural members shall be protected with the BALTIBOND® Corrosion Protection System. The system shall consist of G-235 (Z700 metric) hot-dip galvanized steel prepared in a four-step (clean, pre-treat, rinse, dry) process with an electrostatically sprayed, thermosetting, hybrid polymer fuse-bonded to the substrate during a thermally activated curing stage and monitored by a 23-step quality assurance program. Coatings other than the BALTIBOND® Corrosion Protection System must be submitted to the engineer for pre-approval. Approved equals must have undergone testing, resulting in the following results as a minimum:

1. When X-scribed to the steel substrate it shall be able to withstand 6000 hours of 5% salt spray per ASTM B117 without blistering, chipping, or loss of adhesion.

2. When X-scribed to the steel substrate it shall be able to withstand 6000 hours of exposure to acidic (pH=4.0) and alkaline (pH=11.0) water solutions at 95ºF (35˚C) without signs of chemical attack.

3. Shall withstand impact of 160 in-lbs per ASTM D2794 without fracture or delamination of the polymer layer.

4. Shall with stand 6000 hours of ultraviolet radiation equivalent to 120,000 hours of noontime sun exposure without loss of functional properties.

5. Shall withstand 200 thermal shock cycles between -25ºF and +180ºF (-32˚C and 82˚C) without loss of adhesion or other deterioration.

6. Shall withstand 6000 hours of exposure to 60 psi (42,184 kg/m2) water jet without signs of wear or erosion.

1.4 Quality Assurance: The closed circuit cooling tower manufacturer shall have a management system certified by an accredited registrar as complying with the requirements of ISO-9001:2000 to ensure consistent quality of its products and services. Closed circuit cooling tower manufacturers that are not ISO-9001:2000 certified shall provide an additional year of warranty to the customer at no additional cost.

2.0 Construction Details

2.1 Tower Structure: The closed circuit cooling tower shall be constructed of heavy-gauge steel utilizing double-brake flanges for maximum strength and rigidity and reliable sealing of water-tight joints. All sheared edges shall be protected with a coating of zinc-rich compound.

2.2 Casing Assembly: The closed circuit cooling tower shall include a coil casing section consisting of a serpentine coil, spray water distribution system, and drift eliminators, as indicated by the manufacturer. PVC drift eliminators shall be removable in easily handled sections. They shall incorporate a minimum of three changes in air direction.

2.3 Coil Assembly: The cooling coil shall be fabricated of continuous lengths of all prime surface steel at the manufacturer’s own facility, and hot-dip galvanized after fabrication. The cooling coil shall be pneumatically tested at 375 psig (2,865 kPa). The cooling coil shall be designed for low pressure drop with sloping tubes for free drainage of fluid and shall be ASME B31.5 compliant. Maximum allowable working pressure shall be 300 psig (2,068 kPa) (280 psig (1,931 kPa) for coils supplied with a CRN).

(Alternate) 2.3 Coil Assembly (Galvanized steel coil with cleanable header): The cooling coil shall be fabricated of continuous lengths of all prime surface steel at the manufacturer’s own facility, and hot-dip galvanized after fabrication. The cooling coil shall be designed for low pressure drop with sloping tubes for free drainage of fluid. Removable cover plates permit access to each circuit for pressure cleaning. Coil has a maximum allowable working pressure of 80 psig (650 kPa) and is tested at 125 psig (960 kPa) air pressure under water.

(Alternate) 2.3 Coil Assembly (ASME coil) : The cooling coil shall be fabricated of continuous lengths of all prime surface steel at the manufacturer’s own facility, and hot-dip galvanized after fabrication. The cooling coil shall be pneumatically tested at 375 psig (2,865 kPa). The cooling coil shall be designed for low pressure drop with sloping tubes for free drainage of fluid. Maximum allowable working pressure shall be 300 psig (280 psig for coils supplied with a CRN). The cooling coil shall be designed, built, tested and stamped in accordance with Section VIII, Division 1, of the ASME Boiler and Pressure Vessel Code.

(Alternate) 2.3 Coil Assembly (Galvanized steel coil with additional circuit): The cooling coil shall be fabricated of continuous lengths of all prime surface steel at the manufacturer’s own facility, and hot-dip galvanized after fabrication. The cooling coil shall be designed for low pressure drop with sloping tubes for free drainage of fluid. The cooling coil shall be designed for low pressure drop with sloping tubes for free drainage of fluid. Maximum allowable working pressure shall be 300 psig (280 psig for coils supplied with a CRN). The coil header shall be partitioned. Each coil segment shall include an inlet and outlet connection to allow independent operation of each segment.

(Alternate) 2.3 Coil Assembly (Galvanized steel coil with fins): The cooling coil shall be fabricated of continuous lengths of all prime surface steel at the manufacturer’s own facility, and hot-dip galvanized after fabrication. The cooling coil shall be designed for low pressure drop with sloping tubes for free drainage of fluid. The cooling coil shall be designed for low pressure drop with sloping tubes for free drainage of fluid. Maximum allowable working pressure shall be 300 psig (280 psig for coils supplied with a CRN). Steel fins, spirally wound, optimally spaced for wet/dry operation on designated rows of tubes shall be provided on the coil.

2.4 Water Distribution System: Water shall be distributed evenly over the coil at a minimum flow rate of 4.5 gpm/ft2 (3.1 l/s-m2) to ensure complete wetting of the coil at all times. The distribution system shall consist of large-diameter, non-clog, plastic 360° distribution nozzles spaced across the coil face area in Schedule 40 PVC spray branches by snap-in rubber grommets, allowing quick removal of individual nozzles or complete branches for cleaning or flushing. Nozzles shall utilize a two-stage diffusion pattern to provide overlapping, umbrella spray patterns that create multiple intersection points with adjacent nozzles.

2.5 Spray Pump System: The closed circuit cooling tower shall include a close-coupled, bronze-fitted centrifugal pump equipped with a mechanical seal, mounted on the basin and piped to the suction strainer and water distribution system. It shall be installed so that it can be drained when the basin is drained. The pump assembly shall include a metering valve and bleed line to control the bleed rate from the pump discharge to the overflow connection. The pump motor shall be totally enclosed fan cooled (TEFC) type suitable for _____ volts, ____ phase, ______ Hz electrical service.

(Alternate) 2.5 Spray Pump System-Remote Sump: On installations requiring a remote sump, the closed circuit cooling tower shall be modified to accommodate the use of an independent basin and pump (both by others) for recirculating water. 2.6 Basin Assembly: The combination basin/fan section shall be constructed of heavy-gauge G-235 (Z700 metric) galvanized steel. The basin shall be provided with large area lift out strainers with perforated openings sized smaller than the water distribution nozzles and an anti-vortexing device to prevent air entrainment. The strainer and vortex device shall be constructed of the same material as the cold water basin to prevent dissimilar metal corrosion.

3.0 Mechanical Equipment

3.1 Fan System: The fans and motors shall be factory installed at the base of the unit in the dry entering air stream to provide greater reliability and ease of maintenance. The forwardly curved centrifugal fans shall be heavy-duty centrifugal flow type, statically and dynamically balanced prior to shipment. Fan housings shall have curved inlet rings for efficient air entry and rectangular discharge cowls shall extend into the basin to increase fan efficiency and prevent water from entering the fans.

3.2 Bearings: Fans shall be mounted on a steel fan shaft supported by heavy-duty self aligning, relubricatable bearings with cast iron housings and designed for a minimum L10 life of 40,000 hours (280,000 hrs average life).

3.3 Fan Motor/Drive System: Fan motor(s) shall be totally enclosed fan cooled (TEFC) type with a 1.15 service factor, suitable for _____ volts, ____ phase, ____ Hz electrical service and shall be mounted on an easily adjusted, heavy-duty motor base. V-belt drives shall be designed for not less than 150% of motor nameplate horsepower.

(Alternate) 3.3 Fan Motor/Drive System: Fan motor(s) shall be totally enclosed fan cooled (TEFC) inverter duty type with a 1.0 service factor, suitable for _____ volts, ____ phase, ____ Hz electrical service. Motor shall be designed per NEMA Standard MG1, Section IV, Part 31. V-belt drives shall be designed for not less than 150% of motor nameplate horsepower.

3.4 Mechanical Warranty: The fan(s), fan shaft(s), bearings, supports, and fan motor(s) shall be warranted against defects in materials and workmanship for a period of five (5) years from date of shipment.

(Alternate) 3.5 ENERGY-MISER® Fan System: Two single speed fan motors, one sized for full speed and load, the other sized for 2/3 speed and approximately 1/3 of full load horsepower shall be provided in each cell for capacity control and standby protection from drive or motor failure. Two speed motor(s) is not an acceptable alternative.

(Alternate) 3.5 BALTIGUARD PLUS™ Fan System: Two single speed fan motors, one sized for load, the other sized for 1/3 of the full load horsepower shall be provided in each cell for capacity control and standby protection from drive or motor failure. The manufacturer of the equipment shall supply controls for the larger motor, a VFD for the smaller motor and factory programmed logic controller to maximize energy saving for off peak load and wet-bulb conditions.

4.0 Sound

4.1 Sound Level: To maintain the quality of the local environment, the maximum sound pressure levels (dB) measured 50 ft (15,240 mm) from the closed circuit cooling tower operating at full fan speed shall not exceed the sound levels detailed below.