DLA A-A-59223-1998 COOLING TOWERS LIQUID《液体冷却器》.pdf

1、INCH-POUNDA-A-59223May 18, 1998SUPERSEDINGF-C-2791November 29, 1991COMMERCIAL ITEM DESCRIPTIONCOOLING TOWERS, LIQUIDThe General Services Administration has authorized the use of thiscommercial item description for all Federal agencies.1. SCOPE. This commercial item description (CID) covers factory a

2、ssembled, inducedmechanical draft and forced mechanical draft cooling towers for commercial and industrial use.2. CLASSIFICATION. The cooling towers shall be of the following types, as specified(see 7.2).TYPEType I - Induced mechanical draft.Type II - Forced mechanical draft.3. SALIENT CHARACTERISTI

3、CS.3.1 Description . The cooling towers shall be of the induced mechanical draft or forcedmechanical draft type as specified (see 2. and 7.2). The cooling towers shall be comprised of thefollowing components and parts: frames and casings, louvers, drift eliminators, partitions, coldwater basin equip

4、ment, fans, blowers, drives, electric motors, access doors, ladders, workingplatforms (if specified), inspection plates, and panels.3.2 Standard commercial product . The cooling tower shall, as a minimum, be in accordance withthe requirements of this CID and shall be the manufacturers standard comme

5、rcial product.Additional or better features which are not specifically prohibited by this CID, but which are aBeneficial comments, recommendations, additions, deletions, clarifications, etc. and any datawhich may improve this document should be sent to: Commanding Officer (Code 15E2), NavalConstruct

6、ion Battalion Center, 1000 23 rd Avenue, Port Hueneme, CA 93043-4301, by usingthe Standardization Document Improvement Proposal (DD Form 1426) appearing at the end ofthis document or by letter.AMSC N/A FSC 4130Provided by IHSNot for ResaleNo reproduction or networking permitted without license from

7、IHS-,-,-A-A-592232part of the manufacturers standard commercial product, shall be included in the cooling towerbeing furnished. A standard commercial product is a product which has been sold or is beingcurrently offered for sale on the commercial market through advertisements or manufacturerscatalog

8、s or brochures, and represents the latest production model.3.3 Interchangeability . All units of the same classification furnished with similar options under aspecific contract shall be identical to the extent necessary to ensure interchangeability ofcomponent parts, assemblies, accessories, and spa

9、re parts.3.4 Safety . Heavy-duty metal guards or enclosures shall be provided over all fans and aroundother rotating or reciprocating parts in accordance with Occupational Safety and HealthAdministration (OSHA) regulations. Inlets and openings other than louvered openings shall beprovided with readi

10、ly removable screens. Discharge fans shall be protected by a ruggedly framedscreen or guard installed outside the fan and removable for service conforming to OSHAregulations. Ladders, safety cages, handrailings, working platforms, and fittings shall be providedwhere required, in accordance with OSHA

11、 regulations. All towers shall be designed andconstructed to provide ready access for maintenance, servicing and repair.3.5 Construction . The design of the cooling tower shall meet the requirements of this CID. Alltowers shall be constructed to withstand a wind pressure of not less than 30 pounds f

12、orce persquare foot ( psf) (1.44 kilopascal (kPa) on any external surface. Fan decks shall be constructedto withstand a live load of not less than 60 psf (2.87 kPa) in addition to the concentrated ordistributed loads of equipment mounted thereon. When specified (see 7.2), a 15 percent increasedloadi

13、ng shall be included for ice or snow load. The hot water distribution system shall be of theopen basin gravity feed type or the pressurized spray header type design.3.5.1 Towers and tower frames. The tower frame material shall be as specified (see 7.2).3.5.2 Cold water basins and casings. Casings sh

14、all have suitable seals and flashings at joints andconnections to ensure watertight construction and to minimize and control leakage.3.5.3 Inlet and discharge terminations. When specified (see 7.2), on forced draft centrifugal typeunits the air inlet and discharge terminations shall have flanged or

15、lipped projections forconnecting to duct work.3.5.4 Frames and louvers. Intermediate structural members shall be provided, wheneverrequired, for rigidity and support of casings, louvers, fill, distribution systems, fan decks, andother equipment. Inlet air louvers shall permit free air passage and be

16、 designed to prevent debrisand sunlight from entering the cold water basin while eliminating splashout.3.5.5 Fill or contact surfaces. The fill shall support expected loads without sag or failure andarranged to effectively break up the water. The fill shall be manufactured and performance testedby t

17、he cooling tower manufacturer. The fill shall be of the materials as specified (see 7.2).Polyvinyl chloride fill is suitable for inlet temperatures to 125 degrees Fahrenheit ( F)Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-592233(51.7 degrees

18、Celsius ( C) on cross flow type units and temperatures to 130 F (54.4 C) oncounterflow type units. Chlorinated polyvinyl chloride fill shall be used for applications whereinlet temperatures are greater than 130 F (54.4 C).3.5.6 Drift eliminators. Drift eliminator sections shall be designed in accord

19、ance with commercialpractice and arranged to effectively trap water droplets entrained in the discharge airstream.Sections shall be assembled in easily removable sections for type II and counterflow type I towers.3.5.7 Partitions, windbreak baffles, drift-check walls, and fan walls. Partitions, wind

20、break baffles,drift-check walls, and fan walls, when provided, shall be installed to suit design and capacity oftower, as ordered.3.5.8 Cold water basin equipment. The following equipment shall be furnished by the equipmentsupplier for all towers: sump with removable screen and vortex breaker, float

21、 valves, and allnecessary pipe connections and fittings within the tower. Float valves when provided shall be ofadequate sizes on adjustable arms. Sizes larger than 0.50-inch (12.70 mm) shall be the balancedpiston type. Valve seats and composition disks shall be replaceable.3.5.9 Fans, blowers, and

22、drives. The towers shall have propeller-type fans having not less thanfour blades or squirrel-cage, centrifugal-type blowers, as applicable. Centrifugal type blower fansshall be dynamically balanced. Wood fan blades are not acceptable. Fans and blowers shall becapable of withstanding 50 percent over

23、speed above normal maximum operating speeds. Fan andblower tip speeds shall be held within ranges which will permit conformance to sound levelrequirements specified herein (see 3.6.1). Drive components and supports shall be heavy-dutythroughout. Forced draft towers shafts shall be the hollow type wi

24、th outboard ball bearings or thesolid type with outboard ball bearings and oil lubricated intermediate sleeve bearings. Induceddraft towers shafts shall be solid type with outboard ball bearings. Bearings shall have L10 life ofnot less than 75,000 hours for type I towers and 40,000 hours for type II

25、 towers. If belt drivesare utilized, multi-grooved solid back single belt design shall be used to avoid uneven belt stretch.Adjustment shall be provided for belt tension and drive centers shall be not greater than 50 inches(1 270 mm). Belt drives shall be designed for 150 percent overload. Sheaves l

26、ocated in the airstream shall be corrosion-resistant material. Shafting for gear drives shall have flexible-typecouplings requiring no lubrication. Reduction gears shall be right angle, spiral bevel gear typewith a service factor of not less than 2.0, or a service factor of 1.67 for intermittent dut

27、yapplications. The gear and pinion of the spiral bevel type shall be lapped together. The gearassembly shall be enclosed in an oil filled housing provided with fill and drain plugs. The housingshall be of rigid construction to maintain precise alignment of gears under all loadings. Gear boxshall be

28、warranted for a period of five years from date of shipment by the manufacturer withproper routine maintenance.3.5.10 Pipe and fittings. Plastic pipe, when used, shall be not less than schedule 40 and conformto ASTM D 2996. Plastic fittings shall be of the same kind, class, and grade as the plastic p

29、ipeused. Fittings for other pipe shall be of the same material or equal and of the same class andgrade as the pipe. Materials used for joint compounds shall be in accordance with commercialpractices.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A

30、-5922343.5.11 Hardware. Hardware material shall be as specified (see 7.2).3.5.12 Electric motors. All motors used in tower installations shall be of the totally enclosed typewith voltage, frequency, and phase characteristics as specified (see 7.2). Fractional horsepower(watt (W) alternating current

31、(ac) motors shall conform to NEMA MG 1. Integral horsepower(hp) (W) ac motors shall conform to NEMA MG 1. Fan motors, 1 hp (746 W) and above, shallbe of the reversible two-speed type, when specified (see 7.2), and shall have single winding withvariable torque characteristics.3.5.12.1 Vibration cutou

32、t switch. When specified (see 7.2), a vibration cutout switch shall besupplied and installed in a protected position and in the most effective location, and interlockedwith the fan wiring to electrically open the motor circuit under excessive fan vibration.3.6 Performance . The performance of the to

33、wers shall be specified in terms of water flow, hotwater temperature, cold water temperature, and wet bulb temperature, as specified (see 7.2). Theperformance of the towers shall be based on an ambient wind velocity of 3 miles per hour(4.83 kilometre per hour). Other design and rating requirements a

34、nd permissible variations fromthe design conditions shall be in accordance with ASME PTC 23 or CTI ATC-105. A writtenthermal performance guarantee shall be provided by the cooling tower manufacturer.3.6.1 Sound power level. Sound power levels (in decibels (dB) with a reference pressure of0.0002 micr

35、obars) of the cooling tower shall be not greater than the maximum permitted dB levelsfor the designated octave band as set forth in table I or table II. The sound power level data forthe cooling tower shall be based on tests conducted in accordance with ASA S1.13.TABLE I. Sound power level (type I t

36、owers) .Octave Band (Hertz) 63 125 250 500 1000 2000 4000 8000Sound power level (dB) 112 112 110 108 102 98 93 90TABLE II. Sound power level (type II towers) .Octave Band (Hertz) 63 125 250 500 1000 2000 4000 8000Sound power level (dB) 105 102 99 99 94 92 89 843.6.2 Drift loss. Drift loss shall be n

37、ot greater than 0.005 percent of the water circulated.3.7 Lubrication . Unless otherwise specified (see 7.2), a means for lubrication shall be inaccordance with the manufacturers standard practice. The lubricating points shall be extended tothe outside of the unit for easy accessibility. Hydraulic l

38、ubrication fittings shall be in accordancewith SAE J534. Where use of high pressure lubricating equipment, 1,000 pounds per square inch(6 894 kPa) or higher, will damage grease seals or other parts, a suitable warning shall be affixedto the equipment in a conspicuous location.Provided by IHSNot for

39、ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-5922353.8 Anti-corrosion treatment . All punched, sheared, welded or exposed metallic areas, shall betreated with a cold galvanizing compound in accordance with good commercial practice, andsurfaces overcoated with a fact

40、ory coating or paint system that will withstand a salt-spray fog testin accordance with ASTM B 117.3.9 Fire protection . When specified (see 7.2), field erected towers constructed of flammablematerials shall have a fire protection system and other provisions in conformance with theNFPA 214.3.10 Iden

41、tification marking . Identification shall be permanently and legibly marked directly onthe tower or on a corrosion-resisting metal plate securely attached to the tower at the source ofmanufacturer. Identification shall include the manufacturers model and serial number, name, andtrademark to readily

42、identify the manufacturer.4. REGULATORY REQUIREMENTS.4.1 Materials . The offeror/contractor is encouraged to use recovered materials to the maximumextent practicable, in accordance with paragraph 23.403 of the Federal Acquisition Regulation(FAR). Unless otherwise specified herein, all equipment, mat

43、erial, and articles incorporated in thework covered by this commercial item description are to be new and fabricated using materialsproduced from recovered materials to the maximum extent possible without jeopardizing theintended use. The term “recovered materials” means materials which have been co

44、llected orrecovered from solid waste and reprocessed to become a source of raw materials, as opposed tovirgin raw materials. Unless otherwise specified, none of the above shall be interpreted to meanthat the use of used or rebuilt products are allowed under this commercial item description.4.2 Metri

45、c products . Products manufactured to metric dimensions will be considered on an equalbasis with those manufactured using inch-pound units, provided they fall within specifiedtolerances using conversion tables contained in the latest version of ASTM SI-10(IEEE/ASTM SI-10), and all other requirements

46、 of this commercial item description includingform, fit, and function are met. If a product is manufactured to metric dimensions and thesedimensions exceed the tolerances specified in the inch-pound units, a request should be made tothe contracting officer to determine if the product is acceptable.

47、The contracting officer has theoption of accepting or rejecting the product.5. QUALITY ASSURANCE PROVISIONS.5.1 Product conformance . The products provided shall meet the salient characteristics of thiscommercial item description, conform to the producers own drawings, specifications, standards,and

48、quality assurance practices, and be the same product offered for sale in the commercialmarket. The government reserves the right to require proof of such conformance.6. PACKAGING. The preservation, packing, and marking shall be as specified in the contract ororder.Provided by IHSNot for ResaleNo rep

49、roduction or networking permitted without license from IHS-,-,-A-A-5922367. NOTES.7.1 Source of documents .7.1.1 Occupational Health and Safety Administration (OSHA) regulations may be obtained fromthe Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.7.1.2 The Federal Acquisition Regulation (FAR) and Code of Federal Regulations (CFR) may beobtained from the Superintendent of Documents, U.S. Government Printing Office, Washin