/ Marley Sigma Steel Cooling Tower /

Transcription

1 / Marley Sigma Steel Cooling Tower /

2 / The Marley Difference / You ll enjoy single source responsibility and reliability because SPX Cooling Technologies designs and manufactures virtually all major cooling tower components. All Marley components are designed and selected to be part of an integrated system. For example, the spray pattern from nozzles and the pressure drop through drift eliminators both affect a fill s heat transfer capacity. So, we include that impact in our thermal analysis. Drift eliminators must be effective at the air velocities where fill is most efficient. So, we ve carefully designed both components to work together efficiently. How many other cooling tower companies can offer you this assurance? They may use Brand A nozzles with Brand B fill and Brand C drift eliminators. When they all come together, the whole may be less than the sum of the parts. Our total system approach assures that all the parts work together to provide you the greatest total performance. And because we design specifically for cooling towers, all our components will provide many years of service with minimal maintenance. Approval Available 2

3 / Sigma Tower Advantages / Guaranteed Performance. Don t rely on outside agencies with limited enforcement powers. We ll stand by our responsibility for reliable thermal performance. We designed it. We rate it. We guarantee it. Exclusive 5-Year Mechanical Equipment Warranty. Your no-cost assurance of trouble-free mechanical operation for 5 years. Isn t that where a lot of your tower maintenance dollars have gone in the past? Long Service Life. We ve carefully chosen all the materials used in Sigma Steel towers for their corrosion resistance and suitability for cooling tower service. Heavy gage steel hot dip galvanized after fabrication, stainless steel, PVC and fiberglass keep your Sigma Steel tower working year after year. Efficient Field Assembly. Precise factory fabrication assures that every component in your Sigma Steel tower will fit as designed. SPX Cooling Technologies offers an unparalleled nationwide construction organization to build your tower quickly and economically. Low Operating Costs. Marley high-efficiency fill and fans, gravity-flow water distribution, and efficient Geareducer drive work together to offer maximum cooling with minimum power use. Low Maintenance Costs. Induced-draft propeller fans on Marley rightangle Geareducer units, TEFC 1.0 or 1.15 service factor motors and heavy-duty mechanical equipment support assure long service life with minimal maintenance. All-Season Reliability. Sigma Steel towers perform as specified in the heat of summer. They respond well to energy management techniques in spring and fall. They operate virtually ice-free in the dead of winter. And they offer simple maintenance all year long. We guarantee it. Single Source Parts Availability. SPX designs, manufactures, guarantees, and stocks all major components of the tower except motors. We ll have the parts if you ever need them. 3

4 / Construction and Components / Fill, Louvers, and Drift Eliminators Marley high-performance film fill is the heart of every Sigma Steel tower. A repeating chevron pattern provides the wetted surface and air turbulence necessary for proper heat transfer while minimizing resistance to airflow so you ll save on fan power. Molded protrusions on each fill sheet assure uniform spacing. Mechanical Equipment You ll receive a 5-year warranty against failure of any mechanical component in the fan drive system (except the motor, which is warranted by its manufacturer). Fill sheets are thermoformed from 15 mil (.015 ) thick PVC (polyvinyl chloride) stock capable of service at hot water temperatures up to 125 F. Four stainless steel structural tubes resting in stainless steel hangers support the fill while PVC tubes control alignment at mid-height and at the bottom of the fill. This system also holds the bottom of the fill sheets above the cold water basin floor to simplify basin cleaning. The Marley Geareducer speed reducer used in the Sigma line contributes a long record of dependability, long service life, and low maintenance to this assurance of reliability. Their designs meet or exceed the requirements of CTI STD-111 and AGMA Std Every Geareducer unit is run-in under load prior to shipment to make sure that it will operate properly on your tower. Fill sheets include both louvers and drift eliminators. The louvers in this patented arrangement keep water on the fill sheets and in your tower, and also assure proper heat transfer throughout wide variations in airflow. Users find this fill operates ice-free even in extremely cold weather. Integral drift eliminators prevent the costly nuisance of drift spotting on objects in the sur round ing environment. Their unique shape induces the air flow through three distinct direction changes as illustrated at right. The final turn directs air toward the fan to save you fan horsepower. Moisture carried in the air stream can t make these abrupt turns, so drift is 0.010% or less of the circulating water flow rate. 4

5 Housings are gray cast iron. Gears are high-strength, case hardened alloy steel. And all bearings are tapered roller bearings. A variety of available horsepower capacities and reduction ratios lets us choose the optimum Geareducer model and fan speed for your job. Service factors are always 2.0 or greater as applied. Fans operate inside structural FRP (fiber reinforced polyester) eased-inlet fan cylinders designed and applied to maximize fan performance. Standard cylinders are either 6-0 or 7-0 tall, depending on fan diameter, so all Sigma Steel towers comply with OSHA standards without need of fan guards. Splash-type lubrication and integral cooling fins preclude the need for maintenance-intensive oil pumps and coolers. A constant oil bath or flow lubricates every bearing in forward or reverse motion at full or half speed. All Marley Geareducer assemblies are right-angle type with motors located outside the tower s saturated airstream. A galvanized steel lube line runs from the Geareducer unit to a standpipe near the motor on each cell, so you can check oil level and change or add oil while standing on the fan deck. All Sigma Steel towers offer the benefits of adjustable pitch propeller type Marley fans. The H-3 Series fans normally used on smaller models incorporate cast aluminum blades and machined aluminum hubs. HP-7i Series fans, used on larger models, include hollow GRE (glass-reinforced epoxy) blades and epoxy-coated cast iron hubs. Blades on both fan types are adjustable in pitch, so you can take full advantage of rated horsepower or adjust the pitch to compensate for unusual jobsite restrictions. The true airfoil blades, designed specifically for cooling towers, offer efficient, quiet operation and long service life. Marley driveshafts transmit power from the motor to the Geareducer assembly. Standard Marley driveshafts include 304 stainless steel tubes with welded-on stainless steel flanges and bonded neoprene flexible elements to transmit torque. Marley driveshafts are full-floating assemblies with non-lubricated flexible couplings on each end. Their tolerance to misalignment and torsional shock is unequalled in nonspecialized units. All Marley driveshafts are dynamically balanced at the factory to minimize operating vibrations. Welded unitized hot dip galvanized steel supports maintain alignment throughout the mechanical equipment system. Marley torque-tubes provide superior strength and stability. Their cylindrical shape also keeps operating costs down by minimizing airflow restrictions and by reducing air turbulence in the fan entrance region. Water Distribution System The gravity-flow water distribution system designed into the Sigma tower essentially reduces pump head to its most basic component static lift saving you money on pump power. You won t have to force water through internal piping and pressure spray nozzles, as you would in a counterflow tower. 5

6 Warm water enters the system through the Sigma galvanized crossover pipe. Inlet connections for your piping conform to standard 125# flanges. Marley flow-control valves balance the flow to both distribution basins of each cell. Water flows from the valves into covered FRP stilling chambers, through a longitudinal FRP flume and then into the hot dip galvanized steel distribution basin. Structure and Materials Sigma Steel tower design conforms to the latest edition of the design standards of ASCE (American Society of Civil Engineers). Wind load criterion is normally 30 pounds per square foot of projected area and the design meets 5%g seismic loading. Materials selections are based on a maximum water temperature of 125 F. The Sigma Steel structure is a system of mill shape angles, cold-formed channels, and cold-formed angles. All structural members are hot dip galvanized after fabrication in accordance with ASTM A123. Average zinc thickness on structural members varies from 2.55 mils to 3.9 mils, depending on the steel plate thickness as defined in ASTM A123. Galvanizing after fabrication assures you that the steel in your tower is entirely protected from the effects of corrosion, even on the ends and through bolt holes. You ll enjoy long, reliable corrosion resistance in most operating environments. For even greater protection, you can choose from several stainless steel options, described on page 11. Polypropylene Spiral Target nozzles in the basin floor then distribute the water uniformly over the fill. All materials in the water distribution system offer long life and minimal maintenance. Valves consist of cast iron bodies and grease-lubricated stainless steel operating stems. Basins are hot dip galvanized after fabrication in accordance with ASTM A123, which requires average zinc thickness of 2.55 mils. Polypropylene nozzles and FRP flumes are chemically and biologically inert. Columns in all Sigma Steel towers are cold-formed channels located on 4-0 longitudinal centers. All columns are anchored to the basin. Transverse channel diagonals carry lateral loads to heavy-duty hot dip galvanized steel anchor plates. Mill shape angles provide longitudinal bracing. 6

7 All structural framing connections use 1/2 or 5/8 diameter hot dip galvanized machine bolts. The fan deck is hot dip galvanized steel designed for a uniform live load of 60 psf. Access and Safety The Sigma Steel tower is designed to meet all OSHA requirements. A 3-6 high galvanized guardrail system complete with top rails, intermediate rails and toeboards, surrounds the entire top perimeter of the tower. Casing Tower endwalls are cased with gray 8 oz/sq ft corrugated FRP sheets. Water and corrosion-proof, FRP is immune to biological deterioration and requires no maintenance. Corrugations run vertically. All vertical joints between sheets are overlapped one corrugation and are sealed. Casing attaches to the structural members with stainless steel fasteners and neoprene bonded washers. Corner trim pieces are 12 oz/sq ft molded FRP. Cold Water Basin Most Sigma Steel owners install their towers over concrete cold water basins provided by others. However, you can choose a Marley steel collection basin with side outlet sump as an option. See page 10. Consult your Marley sales representative for detailed dimensional drawings and load schedules to help you with your basin design. Aluminum ladders attached to the tower endwalls provide access to the fan deck level. Ladders begin at the cold water basin level and end at the top of the guardrail system. Each tower normally includes two ladders (one at each endwall). Hinged doors through the endwall casing at each end of the tower plus accessways through any and all partition walls permit access to the interior of the tower at the basin level. All mechanical equipment is accessible both from the interior of the tower and through the fan cylinder. Every component of every tower is removable and replaceable. 7

8 / Available Options / Accessory Description and Remarks Accessory Description and Remarks HDG Steel Cold Water Basin Hot dip galvanized steel collection basin with side-outlet sump for towers located above grade. See page 10. FM (Factory Mutual) Approval Simple modifications allow Sigma Steel towers to meet Factory Mutual requirements for fire resistant construction. Stainless Steel Cold Water Basin Bottom Outlet Sump Collection Basin Clean-Out Box Steel Casing Stainless Steel Construction Cell Partitions Steel Hot Water Basin Covers For corrosive environments or where dictated by experience or personal preference. See pages 10 and 11. Square-plan galvanized steel sump with bottom outlet. Outlet connection hole and bolt circle conform to 125# ASME pipe connection. Includes a plugged drain connection in sump bottom. Square-plan galvanized steel box with 3 or 4 diameter bottom outlet flange connection facilitates basin cleaning. G-235 mill-galvanized steel sheets are installed with interlocking flanges at all horizontal joints. Choose from several options, providing different degrees of protection against corrosion. See page 11. Basin partitions between fan cells for specific operating considerations. See page 9. Removable, G-235 galvanized steel covers keep upper basins free of leaves and debris. They also tend to retard growth of algae by keeping ultraviolet radiation away from the warm water in the basins. Covers may be used as a walking surface for tower maintenance. Steel Stairway Steel Ladder Ladder Safety Cage Plenum Walkway Ladder Extensions Hot dip galvanized steel 45 stairway located at tower endwall provides access to the fan deck. Choose a stairway in place of one endwall ladder, or use both ladders as well as the stairway. Handrails and kneerails are standard, so design conforms to OSHA standards. Galvanized steel ladder conforms to OSHA standards. May be in place of or in addition to standard aluminum ladders. Galvanized steel circular framework bolts to ladder siderails and conforms to OSHA standards. Cages extend from the top of the guardrail to about 7-0 above the base of the ladder. If the tower fan deck is more than 20-0 above roof or grade, OSHA requires safety cages. Hot dip galvanized steel plenum walkways extend the full length of the tower from access door to access door above the water line. Guardrails are optional. However, OSHA requires guardrails if the walkway is 4-0 or more above the basin floor. Used when tower is elevated appreciably above access level. Extensions attach to the normal ladder and may require base anchorage (depending on length). Air Inlet Screens Vibration Limit Switches Galvanized wire mesh screens over the air inlets keep leaves and trash out of the tower. Easily removable. Includes galvanized steel U-edge frames. Stainless steel screens and frames are also available. Robertshaw or Metrix single-pole, double-throw vibration switches in NEMA 4 housing. Doublepole, double-throw models are also available. Non-Skid Fan Deck Covering Fan Cylinder Extensions Non-slip strips overlayed on walking areas provide extra security for operating and maintenance personnel. Optional flared fan cylinder extensions improve fan efficiency to reduce your operating costs. Extensions increase cylinder height to Not available for 120 fan diameters. Geareducer Oil Level Gauge A brass-fitted oil level sight glass takes the place of the dip stick on the external oil fill and drain system. Permits easy reading of oil level and also lets you change oil through the lube line. 8

9 / Available Options / Ladder with Safety Cage Cell Partition Options Every Sigma Steel tower includes plenum chamber partitions, fill area partitions and hot water distribution basin partitions between adjacent cells. Plenum partitions ensure consistent thermal performance as you shut off one fan at a time. They keep air from entering an operating cell through an adjacent idle fan, an effect that reduces thermal performance. Collection basin partitions let you inspect and clean individual basins while the rest of the tower continues to operate. Oil-Level Sight Glass Complete watertight partitions provide total cell isolation. These partitions let you use adjacent cells to serve separate loads with incompatible system temperatures. Watertight partitions extend from louver-face to louver-face and cover the full internal height of the tower, including the cold water basin. Partitions usually consist of G 235 galvanized steel, sealed to cold water basin partitions made from the same material as the basin sides. For concrete basin partitions, Marley drawings specify the appropriate design dimensions. Partitions in Marley steel collection basins include bolt-on steel weir plates to let you mix or segregate the water in the basin to meet your operating needs. Steel Casing 9

10 / Special Component Options / Cold Water Collection Basins If you plan to locate your tower above grade, a Marley steel cold water collection basin, in either galvanized or stainless steel construction, complete with the necessary operating accessories is available as an option. Galvanized basins are hot dip galvanized after fabrication and assembled using field bolted and sealed joints between adjacent sheets. Stainless steel basins may be either field bolted or field welded, depending on your preference, but can only be specified with an all stainless steel Sigma tower to eliminate the potential for galvanic corrosion between galvanized and stainless steel. Every standard basin includes at least one depressed, side-outlet sump. The number and size of sumps depend on the circulating water rate and the overall size of the tower. Unless otherwise specified, sumps include a drain and a stainless steel or hot dip galvanized debris screen. You may choose either galvanized or stainless steel construction. Each basin includes at least one overflow/cleanout connection consisting of a full coupling and standpipe. The normally-installed standpipe ensures adequate freeboard in the cold water basin and removes easily for flush-out basin cleaning. A float-operated, mechanical make-up valve provided with each basin automatically replenishes water lost from the system. The valve is located in the plenum chamber between fill banks, just inside the endwall access door to facilitate adjustment and maintenance. Non-Standard Motors Although you can buy your Sigma Steel tower less motor at a cost reduction, it is not normally recommended. Motors supplied on Marley towers meet rigorous specifications developed from environmental chamber tests at our Development Center. These specifications represent prudent minimum design requirements. Depressed side-outlet sump High Design Loadings Our engineers will make sure that your Sigma Steel tower will withstand any higher-than-normal design loadings (wind, seismic, decking, etc.) that you may specify. Clearly define any special design requirements in your tower specifications. We ll make any necessary changes to the tower s structural design. This is equally true if you anticipate incoming hot water temperatures above 125 F. The specification should also describe the type of load system served by the tower and include the expected water quality analysis so that our engineers can select and recommend appropriate changes in component materials to assure satisfactory service. Discuss any questions about technical requirements with your trained Marley sales representative. Unless otherwise specified, motors provided on Marley cooling towers are TEFC, 1.0 or 1.15 service factor (appropriate to the applied load), 1800 RPM. Other enclosures (such as Explosion Proof) and motors specially wound for non-standard voltages are available at extra cost. Two-speed motors and motors for variable speed drive applications are also available. Their advantages are discussed in the Sigma Steel Technical Reference Manual. 10

11 / Corrosion Protection / Hot Dip Galvanized After Fabrication Sigma Steel towers meet the rigorous demands of the industrial user and the user with large HVAC loads. Cooling towers on these types of applications are usually very critical, so the standard materials of construction on all Sigma Steel towers offer excellent corrosion resistance. A primary example is the use of steel that has been hot dip galvanized after fabrication for all structural members, all steel components (except those that are stainless steel) in the wetted section of the tower and all mechanical equipment supports. Hot dip galvanizing after fabrication offers several advantages over mill-galvanizing used by suppliers of similarcapacity units: Thicker zinc application. Average zinc thickness on steel hot dipped after fabrication is 2.55 mils on all steel up to and including 1/16 thick and 3.91 mils on steel from 1/16 to 1/8 thick. By contrast, the G-210 mill-galvanized steel offered by other suppliers is only 1.9 mils thick. Sigma Steel towers offer from 34% to 106% additional protection based on zinc thickness alone. More effective edge protection. Galvanizing after fabrication assures that all sheared and cut edges receive the full zinc thickness. Mill-galvanized material relies on the zinc adjacent to the sheared or cut edge to protect the exposed steel in those areas. Your Sigma Steel tower will have full protection at all bends, shears, bolt holes throughout the entire tower. Available on heavier-gauge materials. The steel thicknesses used for structural members on the Sigma Steel tower are typically heavier than those available with mill-galvanizing. The critical nature of most Sigma Steel tower installations demands structural design appropriate for industrial applications. Hot dip galvanizing after fabrication provides corrosion protection for these heavier sections. The advantages of hot dip galvanized protection after fabrication assure you that your Sigma Steel will provide years of reliable service even on critical industrial applications. If you want even greater protection, select from the options below. / Optional Materials / Premium Materials All materials used in Sigma Steel towers offer long service life in the corrosive cooling tower environment. PVC fill, FRP and other plastic components are inherently noncorrosive. Steel components are either stainless steel or heavygalvanized, depending on their location and service in the tower. If your application involves an unusually corrosive environment or chemically aggressive water, or if you prefer the ultimate in corrosion resistance, you can choose from several options: Stainless hardware. 300 series stainless steel structural hardware (bolts, nuts and washers). The rest of the tower remains heavy galvanized steel. Stainless steel driveshafts. Standard 300 series stainless steel tube and flange with cast 316 stainless steel connecting yokes. Remember that critical steel components such as fill supports and fan assembly hardware are stainless steel on every Sigma Steel tower as standard. If you have questions or concerns about material upgrades, contact your Marley sales representative. Give us an analysis of your anticipated water quality and we ll offer material recommendations for maximum service life at minimal cost. All 300 series stainless steel tower. Every steel component on the tower is stainless steel with the exception of the mechanical equipment. This includes the optional collection basin, if specified. 11

12 / Additional Services / SPX Cooling Technologies is dedicated to satisfying the needs of our customers needs which begin far in advance of the actual purchase of a new Marley cooling tower, and vary over the operating lifetime of the project. Here is a partial listing of the additional services offered by SPX Cooling Technologies to help you do your job most effectively: Application/Sizing/Layout Services Sales Engineers are trained to help you choose the proper type and size of cooling tower, and will guide you in its appropriate location on site. They will also help you write the specifications for its purchase. As the only manufacturer who makes all types of cooling products, SPX Cooling Technologies can offer you a wide range of options to meet your requirements. Construction Service We can supply supervision only or a complete, experienced crew to handle construction. Parts Service We maintain a stock of spare parts specific to your Marley tower. Maintenance Service In addition to providing complete instructions and continuing guidance, we will provide as much hands on maintenance as you require, or will recommend a local service contractor for your consideration. Condition Inspection Service From time to time, for your peace of mind, our engineers can give your tower a thorough inspection to evaluate its current condition. This usually allows you to foresee and forestall problems before they become serious. Reconstruction Service Due to operating or atmospheric conditions, or age, sooner or later your tower will be in need of repairs above and beyond those categorized as normal maintenance. Our reconstruction service can return your tower to as new condition Performance Improvement Service Systems served by cooling towers grow in response to demand for the product produced by that system. Most customers find that they could produce more product if the cooling tower could deliver colder water. Fortunately, cooling tower technology advances with time, and we can apply this increased technology to upgrade your tower s thermal performance. Tower Replacement Service Occasionally, customers will benefit from replacing an installed tower, rather than refurbishing it. SPX Cooling Technologies stands ready to assist you in that endeavor and, in most cases, the replacement will require little or no change to your concrete basin or support structure WEST 129 STREET OVERLAND PARK, KANSAS UNITED STATES spxcooling@spx.com spxcooling.com In the interest of technological progress, all products are subject to design and/or material change without notice SPX Cooling Technologies, Inc. Printed in USA STL-SIG-05

13 / Marley Sigma Steel Cooling Tower / Engineering Data & Specifications

14 Marley / Sigma Steel Cooling Tower / Table of Contents Engineering Data Schematic 6 Support 7 Concrete Basin 8 Piping 9 Environmental 10 Energy Management 11 Specifications / Base Base 12 Thermal Performance 13 Construction 14 Fan Deck and Fan Cylinder 15 Mechanical Equipment 15 Fill, Louvers and Drift Eliminators 17 Hot Water Distribution System 18 Casing 18 Access 18 Cold Water Collection Basin 19 Scope of Work 19 Specifications / Options Control Options Control System 20 Basin Heater 21 Fan Motor Variable Speed Drive 21 Marley Premium VFD System 22 Vibration Limit Switch 23 Convenience and Safety Options Stairway 24 Plenum Walkway 24 Ladder Extension 24 Ladder Safety Cage 24 Oil Level Sight Glass 25 Miscellaneous Options Steel Cold Water Basin 25 Factory Mutual Approval 25 Hot Water Basin Covers 25 Air Inlet Screens 25 Low Noise Tower 26 Service Life-Relate Customization 27

15 Marley / Sigma Steel Cooling Tower / 5 The Sigma Steel is a galvanized steel, field-erected, general purpose crossflow cooling tower, designed to serve normal air conditioning and refrigeration systems as well as medium sized industrial loads. Evolving from the crossflow concept of towers pioneered by Marley in 1938, and incorporating over 70 years of design advancements, the Sigma Steel represents the current state of the art in this cooling tower category. This booklet not only relates the language to use in describing an appropriate Sigma Steel cooling tower but also defines why certain items and features are important enough to specify with the intention of insisting upon compliance by all bidders. The left-hand column of pages 11 thru 25 provides appropriate text for the various specification paragraphs, whereas the right-hand column comments on the meaning of the subject matter and explains its value. Pages 12 thru 19 indicate those paragraphs which will result in the purchase of a cooling tower which will not only accomplish the specified thermal performance but which will include normal operation- and maintenance-enhancing accessories and features. It will also incorporate those standard materials which testing and experience has proven to provide best results in normal operating conditions. Pages 20 thru 27 provide some paragraphs intended to add those features, components, and materials that will customize the tower to meet the user's requirements. Space does not permit definition and explanation of all of the possible options that can be applied to the Sigma Steel. SPX Cooling Technologies realizes that you, the purchaser, must be happy with the tower's characteristics, and we are prepared to provide or provide for any reasonable enhancement that you are willing to define and purchase. Your needs will become part of the continuing betterment of this Marley product line.

16 Marley / Sigma Steel Cooling Tower / Engineering Data : Schematic 6 W OUT-TO-OUT OF TOWER CL COLUMN CL COLUMN COLUMNCL C DIAMETER FAN 41/2" 41/2" A BAYS AT 4'-0" = L TOP OF FAN CYLINDER Use this data for preliminary layouts only. Obtain current drawing from your Marley sales representative. The UPDATE web-based selection software available at spxcooling.com provides Sigma Steel model recommendations based on customer's specific design requirements. B 13'-11/8" H FAN DECK BASE OF TOWER COLUMNS Tower Model GPM per cell Dimensions W L H A B C Maximum Motor hp Average Pumping Head '-4" 12'-0" 19'-1 1 8" 3 6'-0" 120" ' '-4" 16'-0" 19'-1 1 8" 4 6'-0" 144" ' '-4" 16'-0" 20'-1 1 8" 4 7'-0" 168" ' '-4" 20'-0" 20'-1 1 8" 5 7'-0" 168" ' '-4" 20'-0" 20'-1 1 8" 5 7'-0" 216" ' '-4" 24'-0" 20'-1 1 8" 6 7'-0" 216" ' '-4" 28'-0" 20'-1 1 8" 7 7'-0" 216" ' NOTE 1 Use this bulletin for preliminary layouts only. Obtain current drawings from your Marley sales representative. 2 Last number of model indicates number of cells. Change as appropriate for your selection. Primary engineering data is per cell. 3 Height shown is from base of tower columns to top of fan cylinder. 4 Pumping head shown is from base of tower columns.

17 Marley / Sigma Steel Cooling Tower / Engineering Data : Support 7 6" A SPACES AT 4'-0" = L AIR INLET FACE SUMP W OVERALL OF BASIN CASED ENDWALL FACE OVERFLOW 1'-6" RECOMMENDED OPERATING WATER LEVEL CASED ENDWALL FACE Section 6" AIR INLET FACE INTERMEDIATE BEAM PRIMARY SUPPORT BEAM Plan Tower Model Dimensions Operating Weight lb A W L Single Fan Cell Each Cell Add '-8" 12'-0" '-8" 16'-0" '-8" 16'-0" '-8" 20'-0" '-8" 20'-0" '-8" 24'-0" '-8" 28'-0" NOTE 1 Use this bulletin for preliminary layouts only. Obtain current drawings from your Marley sales representative. 2 Steel beams must include 7 8" dia. holes to accept anchor bolts provided with tower. Other contractors or purchaser must design and erect supporting steel. 3 Maintain at least 2'-0" of clear space at tower endwalls for construction purposes. Air inlet faces must have unobstructed air supply. If obstructions exist nearby, consult your Marley sales representative. 4 Operating weight is wet weight of tower and steel basin, including 6" of water in the cold water basin. 5 View shown is typical single cell beam arrangement.

18 Marley / Sigma Steel Cooling Tower / Engineering Data : Concrete Basin 8 6" MIN. W IN TO IN OF BASIN 6" MIN. CASED ENDWALL FACE 6" MIN. 5" SUMP AIR INLET FACE ANCHOR BOLTS (SEE NOTE 5) AIR INLET FACE A SPACES AT 4'-0" = L PER CELL CASED ENDWALL FACE Plan 6" MIN. 5" 1'-6" RECOMMENDED OPERATING WATER LEVEL 1'-0 Section Tower Model Dimensions Operating Weight lb A W L Single Fan Cell Each Cell Add '-6" 12'-0" '-6" 16'-0" '-6" 16'-0" '-6" 20'-0" '-6" 20'-0" '-6" 24'-0" '-6" 28'-0" NOTE 1 Use this bulletin for preliminary layouts only. Do not use for construction. Obtain current drawings from your Marley sales representative. Concrete basin design and construction are by other contractors or purchaser. 2 Operating weight is total wet operating weight of tower only, excluding water in concrete basin. 3 Maintain at least 2'-0" of clear space at tower endwalls for construction purposes. Air inlet faces must have unobstructed air supply. If obstructions exist nearby, consult your Marley sales representative. 4 Minimum basin depth is 1'-6". Basin depth may vary to suit your storage requirements. 5 All anchor bolts complete with nut and washer must be furnished by others. Bolts must be 3 4" diameter with 1 1 2" all-thread projection. 6 Other contractors or purchaser must design, locate, construct, and furnish sump(s) and overflow(s) to suit requirements. The sump(s) should be designed according to the pump manufacturer s recommendations. Other design sources: ANSI/HI specifications for centrifugal pumps, for vertical pumps, and 9.8 for pump intake design.

19 Marley / Sigma Steel Cooling Tower / Engineering Data : Inlet Piping 9 C TYP. SINGLE CELL CL COLUMN AND ANCHOR BOLT CL FAN CL INLET D TYP. MULTICELL CL FAN CL INLET C CL COLUMN AND ANCHOR BOLT CL F MIN REQUIRED CLEARANCE B DIA FLOW CONTROL VALVE CL FAN CL TOWER E FACE OF A DIA INLET FLANGE MARLEY PIPING STOPS HERE CL G C L OF FLANGE TO BASE OF TOWER COLUMNS (USE FOR STATIC LIFT) Tower Model GPM per cell Dimensions A B C D E F G " 8" 8' " 14'-6 3 4" 6'-0" 12'0" 13'-1 1 4" " 10" 9'-0 1 2" 14'-7 3 4" " 10" 8'-0" 16'-0" 10'-0 1 2" 14'-1 1 4" 14'-7 3 4" " 10" 8'-0" 16'-0" 11'-0 1 2" 15'-1 1 4" 14'-7 3 4" " 10" 11'-0 1 2" 14'-7 3 4" 10'-0" 20'-0" 15'-1 1 4" " 12" 11'-1 1 2" 14'-8 3 4" " 12" 10'-0" 20'-0" 13'-1 1 2" 17'-1 1 4" 14'-8 3 4" " 12" 12'-0" 24'-0" 13'-1 1 2" 17'-1 1 4" 14'-8 3 4" " 14" 14'-0" 28'-0" 13'-5 5 8" 17'-1 1 4" 14'-9 3 4" NOTE 1 Use this bulletin for preliminary layouts only. Obtain current drawings from your Marley sales representative. 2 Pumping head contributed by the tower is static lift G. Actual pumping head will vary according to tower circulating GPM. Total pumping head will be furnished at time of proposal. 3 If your application requires a bypass system, recommended location is through tower endwall into plenum area. Review of the system by SPX engineering is required. 4 Marley piping terminates at face of a cast iron flat face flange. Bolt circle conforms to class 125 lb. ANSI B 16.1 specifications. 5 Supports on tower for crossover piping are part of the tower design. Do not support the riser s dead load or operating load from the tower. Do not brace the riser s seismic or thrust loads against the tower. 6 Butterfly valves or piping expansion joints (if used) are by others and must be located outside the limits of the cooling tower F. 7 Motor must be located 180 from inlet.

20 Marley / Sigma Steel Cooling Tower / Engineering Data: Environmental 10 Sound Control Sound produced by a Sigma Steel tower operating in an unobstructed environment will meet all but the most restrictive noise limitations and will react favorably to natural attenuation. Where the tower has been sized to operate within an enclosure, the enclosure itself will have a damping effect on sound. Sound also declines with distance by about 5 dba each time the distance doubles. Where noise at a critical point is likely to exceed an acceptable limit, several options are available listed below in ascending order of cost impact: In many cases, noise concerns are limited to nighttime, when ambient noise levels are lower and neighbors are trying to sleep. You can usually resolve these situations by using two-speed motors in either 1800/900 or 1800/1200 RPM configuration operating the fans at reduced speed without cycling after hours. The natural nighttime reduction in wet-bulb temperature makes this a very feasible solution in most areas of the world, but the need to avoid cycling may cause the cold water temperature to vary significantly. The Marley Variable Frequency Drive automatically minimizes the tower s noise level during periods of reduced load and/or reduced ambient temperature without sacrificing the system s ability to maintain a constant cold water temperature. This is a relatively inexpensive solution, and can pay for itself quickly in reduced energy costs. Where noise is a concern at all times for example, near a hospital the best solution is to oversize the tower so it can operate continuously at reduced (1200 or 900 RPM) motor speed. Typical sound reductions are 7 dba at 2/3 fan speed or 10 dba at half fan speed. Extreme cases may require inlet and discharge sound attenuator sections however, the static pressure loss imposed by attenuators may necessitate an increase in tower size. This is the least desirable approach because of the significant cost impact and because of the obstruction to normal maintenance procedures. As suggested in the aforementioned Technical Report, it may also be advisable to specify a design wet-bulb temperature 1 F higher than normal to compensate for potential recirculation initiated by the enclosure. You ll benefit from discussing your project with your Marley sales representative. Keeping It Clean Cooling towers are very effective air washers. Atmospheric dust able to pass through the relatively small louver openings will enter the circulating water system. Increased concentrations can intensify system maintenance by clogging screens and strainers and smaller particulates can coat system heat transfer surfaces. In areas of low flow velocity such as the cold water basin sedimentary deposits can provide a breeding ground for bacteria. In areas prone to dust and sedimentation, you should consider installing some means for keeping the cold water basin clean. Typical devices include side stream filters and a variety of filtration media. Water Treatment Contaminants including Legionella, an effective consistent water treatment program is required. Controlling blowdown may be adequate in mitigating the potential of corrosion and scale, but biological contamination can only be controlled with biocides. An acceptable water treatment program must be compatible with the variety of materials incorporated in a cooling tower ideally the ph of the circulating water should fall between 6.5 and 8.0. Batch feeding of chemicals directly into the cooling tower is not a good practice since localized damage to the tower is possible. Specific startup instructions and additional water quality recommendations can be found in the Sigma User Manual which accompanies the tower and also is available from your local Marley sales representative. For complete water treatment recommendations and services, contact your local Marley sales representative. Your Marley sales representative will help you meet your sound requirements. Enclosures Occasionally, cooling towers are located inside architectural enclosures for aesthetic reasons. Although Sigma towers adapt well to enclosures, the designer must realize the potential impact of a poorly arranged enclosure on the tower s performance and operation. The designer must take care to provide generous air inlet paths, and the tower s fan cylinder discharge height should not be lower than the elevation of the top of the enclosure. Obtain a copy of Marley Technical Report #H-004, External Influences on Cooling Tower Performance from your Marley sales representative or on the web at spxcooling.com. CAUTION The cooling tower must be located at such distance and direction to avoid the possibility of contaminated discharge air being drawn into building fresh air intake ducts. The purchaser should obtain the services of a Licensed Professional Engineer or Registered Architect to certify that the location of the cooling tower is in compliance with applicable air pollution, fire and clean air codes.

21 Marley / Sigma Steel Cooling Tower / Engineering Data: Energy Management 11 Cooling towers are usually selected to produce a specific cold water temperature at the higher summertime wet-bulb temperatures. During the remainder of the year, the cooling tower is capable of producing much colder water. Unless your system will benefit from the coldest possible water temperature, you should consider controlling cold water temperatures to higher levels. You ll also save energy by using such control. For greater insight on cold water temperature control, please read Cooling Tower Energy and its Management, Technical Report #H-001A, available from your Marley sales representative or on the web at spxcooling.com. Always control leaving water temperature by manipulating the quantity of air that the fan moves through the tower. Varying the quantity of water flow is not normally recommended and can be harmful in freezing weather. You can alternately start and stop single-speed motors to maintain water temperatures within an acceptable range. However, exceeding a total acceleration time of 30 seconds per hour can overheat the motor, causing the insulation to fail. Limiting the number of motor starts, on the other hand, can produce significant variations in the temperature of the water delivered to the process. Normally, two-speed motors are provided in 1800/900 RPM, single winding configuration, which is the least expensive two-speed option. They are also available in other combinations including the more expensive double winding. Variable Speed Fan Drive Frequency modulation devices work well on induced draft, propeller fan cooling towers such as the Sigma Steel cooling tower. However, their design must include the capability to lock out any critical fan speeds and the very low fan speed ranges. Marley VFD drive systems are designed to combine absolute temperature control with ideal energy management. The cooling tower user selects a cold water temperature and the drive system will vary the fan speed to maintain that temperature. Precise temperature control is accomplished with far less stress to the mechanical equipment components. The improved energy management provides fast payback. Indeed, many utilities offer generous rebates for users having installed VFD drives. Increased flexibility can simplify your operating procedures and save you money in the long run, both on operation and on maintenance. Here are two of the more popular options. Two-Speed Motors Two-speed motors improve operating flexibility by increasing the number of potential operating modes. Users in northern climates will find that the tower can carry winter loads at half-speed; reducing fan power requirements by 85+% during that time. Two-speed motors also help to control icing during wintertime operation. See Marley Technical Report #H-003, Operating Cooling Towers During Freezing Weather, available from your Marley sales representative or on the web at spxcooling.com.

22 Marley / Sigma Steel Cooling Tower / Specifications: Base 12 Specifications Specification Value 1.0 Base: 1.1 Furnish and install an induced-draft, crossflow-type, field-erected, steelframed, PVC-fill, industrial-duty cooling tower of cell(s), as shown on Plans. The limiting overall dimensions of the tower shall be wide, long, and high to the top of the fan cylinder. Total operating horsepower of all fans shall not exceed hp, consisting hp motor(s). Tower shall be similar and equal in all respects to Marley Model. Your specification base establishes the type, configuration, base material, and physical limitations of the cooling tower to be quoted. During the planning and layout stages of your project, you will have focused your attention on a cooling tower selection that fits your space allotment, and whose power usage is acceptable. Limitations on physical size and total operating horsepower avoid the introduction of unforeseen operational and site-related influences. Specifying the number of cells, and the maximum fan hp/cell will work to your advantage. Crossflow towers are noted for the accessibility and maintainability of all operating components. The spacious interior provides easy access to fill, drift eliminators, all basin accessories and is one of two primary access ways to the fan, Geareducer, and other mechanical components. At the fan deck level, the hot water distribution basins are easily inspected and cleaned while the tower is operating, if you wish. The mechanical equipment can also be readily accessed from this level. Except for the cold water basin, no counterflow tower component requiring routine maintenance is as easily accessed. The confined areas that typify counterflow designs can make difficult work for maintenance personnel!

23 Marley / Sigma Steel Cooling Tower / Specifications: Base 13 Specifications 2.0 Thermal Performance: 2.1 The tower shall be capable of cooling GPM of water from F to F at a design entering air wetbulb temperature of F. The cooling tower manufacturer shall guarantee that the tower supplied will meet the specified performance conditions when the tower is installed according to plans. 2.2 The purchaser will arrange for an on-site thermal performance test, to be conducted in the presence of the manufacturer and owner, and under the supervision of a qualified, disinterested third party in accordance with CTI (Cooling Technology Institute) ATC- 105 standards during the first full year of operation. If the tower fails to perform within the limits of test tolerance, then the cooling tower manufacturer will install additional cells and/or make such corrections as are agreeable to the owner and shall pay for the cost of a retest. If the tower still fails to perform as specified, then the manufacturer shall make such reimbursements as are appropriate and agreeable to the owner to compensate for the performance deficiency. Specification Value Your reason for purchasing a cooling tower is to obtain a continuing flow of cooled water as defined in the first paragraph at left. If the tower that you purchase is incapable of performing as specified, then you will not have received full value for your money. Bear in mind that the size and cost of a cooling tower varies directly with its true thermal capability. This paragraph is intended to protect you against either intentional or inadvertent under sizing of the tower by the manufacturer. Judging the level of performance of a cooling tower on critical processes is never easy, and the potential risk of a non-performing cooling tower usually causes the requirement for a mandatory acceptance test to be very desirable. Your contract with the successful bidder should establish the acceptable remedies for missed performance, which might include: The addition of one or more cells of tower, as necessary, to bring the cooling tower to the specified level of performance. This is usually limited to the scope of work as defined in the specs, which means that you (the owner) will have to pay for the additional basin, wiring, starters, piping, etc. The reimbursement of a portion of the total contract price equal to the percentage deficiency in performance. Under no circumstances should you allow the manufacturer to re-pitch the fans to increase motor brake horsepower above that shown in the proposal. That creates additional operating costs that will continue for the life of the tower and imposes no penalty on the manufacturer COLD WATER TEMP. ( F) F RANGE 10 F RANGE 15 F RANGE WET BULB TEMP. ( F) Typical cooling tower performance curve.

24 Marley / Sigma Steel Cooling Tower / Specifications: Base 14 Specifications 3.0 Construction: 3.1 The tower shall be capable of withstanding water having a ph of 6.5 to 8.0; a chloride content (NaCl) up to 300 ppm; a sulfate content (SO 4 ) up to 250 ppm; a calcium content (CaCO 3 ) up to 500 ppm; silica (SiO 2 ) up to 150 ppm; and design hot water temperatures up to 120 F. The circulating water shall contain no oil, grease, fatty acids, or organic solvents. 3.2 The structural framework of the tower, as well as all basins and decking, shall be of heavy gauge cold-formed steel and/or mill shapes, hot-dip galvanized after fabrication to a deposition of at least 2.25 ounces of zinc per square foot. 3.3 Column lines shall be on no greater than 4' longitudinal centers, and the base of all columns shall be firmly anchored. Basic design criteria shall be 30 psf wind load and 5%g seismic load. Framing joints shall be made with 1 2" diameter and larger Series 300 stainless steel machine bolts, nuts and washers. Specification Value The limiting water quality values indicated are those which are acceptable for the normal materials of construction specified. If water of more aggressive quality is anticipated, consider specifying a stainless steel Sigma tower. See page 27. Hot-dip galvanizing after fabrication assures that all steel surfaces will be heavily coated with zinc. All shearing, bending, drilling, punching, etc. will have been completed prior to galvanization. Multicell towers must have plenum partitions between cells. Otherwise, air will be induced downward through an inoperative fan, bypassing the fill entirely. Without these partitions, part-load or off-season operation of the tower would be completely unsatisfactory. 3.4 Towers of more than one cell shall include galvanized internal partitions to separate the fan plenums, and a hinged access door shall be provided in each partition for freedom of access throughout the tower.

25 Marley / Sigma Steel Cooling Tower / Specifications: Base 15 Specifications Specification Value 4.0 Fan Deck and Fan Cylinder: 4.1 The fan deck shall act as a working platform for maintenance personnel. It shall be fabricated of no less than 12 gauge steel, and shall be designed for a uniform live load of 60 psf. 4.2 Fan cylinders shall be molded FRP. They shall be through-bolted to the fan deck structure to provide a consistently stable operating shroud for the fan. The indicated design values for framing and decking not only give you assurance that the tower can withstand long term operation in a hostile environment but that it will accept many years of inspection and maintenance traffic by your operating personnel. Fiberglass-reinforced polyester fan cylinders provide the close tip clearances and smooth airflow contour necessary for good fan performance. The inert, noncorroding nature of FRP assures that these characteristics will persist. Their 6' to 7' height also provides protection for operating personnel. 5.0 Mechanical Equipment: 5.1 Fan(s) shall be propeller-type, incorporating heavy duty blades of cast aluminum or high strength, inert composite material. Blades shall be individually adjustable and replaceable. Fan(s) shall be driven through a rightangle, industrial-duty, oil-lubricated, geared speed reducer. Speed reducers employing pulleys and belts will not be accepted. 5.2 Motor(s) shall be hp maximum, TEFC, 1.15 service factor, and specially insulated for cooling tower duty. Speed and electrical characteristics shall be 1800 (1800/900) RPM, single winding, phase, hertz, volts. Propeller-type fans require only half the operating HP of blower-type fans. They should be readily adjustable to permit compensation for job site conditions that may tend to overload the motor. The fans of one manufacturer require the purchase of special positioners for each increment of fan blade pitch. Standard fan drives of other manufacturers may use V-belts. Considering the size of fans involved and the horsepower applied this is not good design practice. Geareducer drive is far more reliable and trouble free, and is currently offered as an option by at least two other cooling tower manufacturers. Unless otherwise specified, motor speed will be 1800 RPM in 60 Hertz areas and 1500 RPM in 50 Hertz areas. If you prefer the operating flexibility of two-speed operation, please specify the RPM to be 1800/900 (1500/750 in 50 Hertz regions).

26 Marley / Sigma Steel Cooling Tower / Specifications: Base 16 Specifications Specification Value 5.3 Motor shall be located outside the fan cylinder at the fan deck, and shall be connected to the speed reducer by a tubular stainless steel, dynamically balanced driveshaft equipped with neoprene flexible coupling elements. The driveshaft turns at the motor speed and is, therefore, most sensitive to operational imbalance. Stainless steel manufacture assures that the driveshaft will not become unbalanced as a result of corrosion. 5.4 A galvanized oil gauge and drain line shall extend from the gear reducer to the vicinity of the motor, and shall be equipped with a dip stick for oil level measurement. 5.5 The complete mechanical equipment assembly for each cell shall be supported by a rigid, unitized support that resists misalignment between the motor and the gear reducer. Support shall be heavy-wall tubular steel, to which heavy plate platforms for the motor and gear reducer have been welded and the assembly shall be hotdip galvanized after fabrication. The support assembly shall also provide an inlet connection for incoming hot water, and shall serve as a crossover pipe to deliver water to both sides of the tower. Fans of the size used on large cooling towers are applied at speeds and horsepower that generate considerable torque and structural tubular steel resists this torque very effectively. Marley torque-tube assures that all of the mechanical equipment remains aligned, and that the rotating fan is properly positioned within the fan cylinder. 5.6 The mechanical equipment assembly shall be warranted for no less than five (5) years. This warranty shall cover the fan(s), speed reducers, driveshafts and couplings, and the unitized supports. The value of a 5 year mechanical equipment warranty speaks for itself. Except for the motor, all of the mechanical equipment on a Marley tower is made by SPX Cooling Technologies. Cooling tower vendors who purchase commercial fans, gear boxes, driveshafts, etc. may require that you deal directly with those commercial suppliers for warranty satisfaction.

27 Marley / Sigma Steel Cooling Tower / Specifications: Base 17 Specifications Specification Value 6.0 Fill, Louvers and Drift Eliminators: 6.1 Fill shall be film-type, 15 mil thick, thermoformed PVC, with louvers formed as part of each fill sheet. Fill shall be suspended from stainless steel structural tubing supported from the upper tower structure, and shall be elevated above the floor of the cold water basin to facilitate cleaning. Air inlet faces of the tower shall be free of water splash-out. 6.2 Drift eliminators shall be PVC, triplepass, and shall limit drift losses to 0.005% or less of the design water flow rate. Louvers integral with the fill keep the flowing water within the confines of the fill. The separate external louvers used by others permit water to escape the fill and form ice or produce an unsightly situation adjacent to the tower. If you plan to use your tower in the wintertime, particularly for free cooling, integral louvers will put your operating concerns to rest. Vertical blade-type eliminators, as well as misdirected cellular types, cause much of the fan power to be wasted in turning the horizontal flow of air vertical for its exit through the fan cylinder. This power is, of course, not available for contribution to thermal performance. Drift rate varies with design water loading and air rate, as well as drift eliminator depth and number of directional changes. A drift rate of 0.001% is readily available in standard configuration without premium cost. If a lower rate is required, please discuss with your Marley sales representative. Louver Section Drift Eliminator Section Fill Section

28 Marley / Sigma Steel Cooling Tower / Specifications: Base 18 Specifications Specification Value 7.0 Hot Water Distribution System: 7.1 The mechanical equipment support/ crossover pipe shall deliver water to two open hot water basins per cell at the fan deck elevation. Water shall exit these basins to the fill by gravity through metering orifice-type polypropylene nozzles situated in the basin floor. Nozzles shall be easily removable and replaceable. 7.2 Heavy-duty, industrial grade flowcontrol valves shall be provided at the inlet to each basin. These valves shall permit both flow balancing and maintenance shut-off to selected cells, or portions of cells. Valves shall have machined cast iron bodies, with stainless steel operating stems, and heavyduty locking handles. Gravity-flow distribution basins are a feature of crossflow type towers. These basins are out where they can be easily inspected even maintained while the tower is in operation. Spray systems of counterflow towers, sandwiched between the top of the fill and the drift eliminators, are extremely awkward to access and maintain. Marley flow-control valves remain serviceable for the life of the tower, and provide a continuing means of flow-regulation between hot water basins and between cells of multicell towers as well. Towers without valves do not provide this valuable operating flexibility. 8.0 Casing: 8.1 Tower endwalls shall be cased with corrugated FRP panels, attached with corrugations running vertically and overlapped one corrugation at joints. Tower corners shall be finished with FRP corner rolls over the ends of the casing sheets. Steel inner casings provide lateral support for the fill that FRP panels cannot. They also support the FRP casing panels against the high wind loads that will act on the tower during its lifetime. 8.2 In the water-washed fill areas, inner casings of 16 gauge galvanized steel shall also be provided. 9.0 Access: 9.1 There shall be a 33" wide by 61" high access door in each endwall casing to provide access to the interior of the tower. Access doors shall be hinged and equipped with a latch operable from both inside and outside the tower. Internal partitions between cells shall include hinged doors to give free access through the tower. The access doors on other towers may be unreasonably small. Specifying the size of the door will cause those bidders to take excep-

29 Marley / Sigma Steel Cooling Tower / Specifications: Base 19 Specifications Specification Value 9.2 The top of the tower shall be equipped with a sturdy 42" high guardrail system, complete with top rails, intermediate rails and toeboards, conforming to OSHA standards. Guardrails and posts shall consist of 1.66" O.D. x 15 gauge galvanized structural tubing. Posts shall be spaced on centers of 8'- 0" or less. 9.3 One endwall of the tower shall be equipped with a 20" wide aluminum vertical ladder, through-bolted to the endwall structure. Ladder shall rise from the cold water basin level to the top of the fan deck guardrail, and shall be designed and installed in conformance with OSHA standards. tion, alerting you to a potential maintenance headache. Good maintenance practice requires periodic access to the top of the tower to inspect the distribution basins, as well as the structural integrity of the fan deck, fan cylinder, and fan especially the fan blade securing hardware. There are no induced-draft cooling tower designs that are immune to this need! For the comfort and safety of your operating personnel, the Sigma Steel tower includes a ladder and guardrail of the quality and design indicated and we strongly recommend that you require it of all bidders! Portable ladders and other "make-do" access means are inappropriate for equipment of this size and complexity Cold Water Collection Basin: 10.1 The collection basin shall be heavygauge galvanized steel and shall include the number and type of suction connections required to accommodate the out-flow piping system shown on the plans. Suction connections shall be equipped with debris screens. A factory installed, float operated, mechanical make-up valve shall be included. An overflow and drain connection shall be provided in each cell of the tower. The basin floor shall slope toward the drain to allow complete flush out of debris and silt which may accumulate. This basic specification assumes that the tower will be erected over a concrete basin at grade level. If the tower is to be installed on an elevated supporting platform, the steel cold water collection basin indicated on page 24 should be included in the specifications Scope of Work: 11.1 The cooling tower manufacturer shall be responsible for the design, fabrication, and delivery of materials to the project site, and for the erection of the tower over supports provided by others. Unless otherwise specified, all external piping, pumps, controls, and electrical wiring will be outside the cooling tower manufacturer's scope of work. Please be clear in your specifications and inquiry documents regarding the full scope of work expected. That will help assure that your bid comparisons will be made on as equal a basis as possible and will help to avoid any misunderstandings during

30 Marley / Sigma Steel Cooling Tower / Specifications: Options 20 Specifications Control Options Specification Value the execution and implementation of the contract. Control System: 5.7: Add the following paragraph in the Mechanical Equipment section: Each cell of the cooling tower shall be equipped with a UL listed control system in a NEMA 3R or 4X outdoor enclosure capable of controlling single-speed or two-speed motors as required, and designed specifically for cooling tower applications. The panel shall include a main fused disconnect with an external operating handle, lockable in the off position for safety. Across-the-line magnetic starters or solid state soft-start starters as required shall be controlled with a thermostatic or solid state temperature controller. Door mounted selector switches shall be provided to enable automatic or manual control and wired for 120VAC control. Control circuit to be wired out to terminal blocks for field connection to a remote vibration switch and for access to extra 120VAC 50VA control power, overload trip alarms and remote temperature control devices. The temperature controller shall be adjustable for the required cold water temperature. If a thermostatic controller is used it shall be mounted on the side of the tower with the temperature sensing bulb installed in the cold water basin using a suspension mounting bracket. If a solid state temperature controller is used the controller will be door mounted on the control panel. The temperature controller will display two temperatures, one for outgoing water and the other for set point. Water temperature input shall be obtained using a three-wire RTD with dry well in the outlet water piping and wired back to the solid state temperature controller in the control panel. If it is your opinion that the control system for the cooling tower should be part of the tower manufacturer s responsibility, we are in wholehearted agreement with you. Who better to determine the most efficient mode and manner of a tower s operation and to apply a system most compatible with it than the designer and manufacturer of the cooling tower?

31 Marley / Sigma Steel Cooling Tower / Specifications: Options 21 Specifications Specification Value Basin Heaters: 10.2 Add the following paragraph in the Cold Water Basin section: Provide a system of electric immersion heaters and controls for each cell of the tower to prevent freezing of water in the collection basin during periods of shutdown. The system shall consist of one or more stainless steel electric immersion heaters installed in the basin. A NEMA 4 enclosure shall house a magnetic contactor to energize heaters; a transformer to provide 24 volt control circuit power; and a solid state circuit board for temperature and low water cutoff. A control probe shall be located in the basin to monitor water level and temperature. The system shall be capable of maintaining 40 F water temperature at an ambient air temperature of F. The basin heater components described at left represent our recommendation for a reliable automatic system for the prevention of basin freezing. They are shipped separately for installation at the job site. The ambient air temperature that you fill in should be the lowest 1% level of winter temperature prevalent at site. Fan Motor Variable Speed Drive: Marley All Weather ACH550 System 6.4 Add the following paragraph in the Mechanical Equipment section when VFD is used with customers Building Management System: A complete UL listed Variable Speed Drive system in a NEMA 1 indoor, NEMA 12 indoor or NEMA 3R outdoor enclosure shall be provided. The VFD shall use PWM technology with IGBT switching and integrated bypass design. VFD out put switching shall not cause mechanical issues with gearbox teeth or drive shafts. The VFD shall catch a fan spinning in the reverse direction without tripping. The panel shall include a main disconnect with short circuit protection and external operating handle, lockable in the off position for safety. The VFD system shall receive a speed reference signal from the Building Management System monitoring the tower fluid temperature. As an option to receiving the speed reference signal from a building management system, the drive must have the capability to receive a 4-20 ma temperature signal from an RTD transmitter. The VFD shall have an internal PI regulator to modulate fan speed maintaining set point temperature. The drive's panel display shall be able to display the set-point Marley VFD drive systems are designed to combine absolute temperature control with ideal energy management. The cooling tower user selects a cold water temperature and the drive system will vary the fan speed to maintain that temperature. Precise temperature control is accomplished with far less stress to the mechanical equipment components. The improved energy management provides fast payback. Indeed, many utilities offer generous rebates for users having installed VFD drives.

32 Marley / Sigma Steel Cooling Tower / Specifications: Options 22 Specifications Specification Value temperature and cold-fluid temperature on two separate lines. The bypass shall include a complete magnetic bypass circuit and with capability to isolate the VFD when in the bypass mode. Transfer to the bypass mode shall be manual in the event of VFD failure. Once the motor is transferred to the by-pass circuit the fan motor will run at constant full speed. The bypass circuit will not modulate ON and OFF based on fluid temperature. The application must be able to handle very cold fluid temperatures while the VFD is in a by-pass mode. Operator controls shall be mounted on the front of the enclosure and shall consist of start and stop control, bypass/vfd selection, Auto/ Manual selections, manual speed control. To prevent heating problems in the fluid cooloer fan motor and to assure proper gear reducer lubrication the VFD system shall de energize the motor once 25% motor speed is reached and cooling is no longer required. The fluid cooler manufacturer shall supply VFD start-up assistance. Tower vibration testing throughout the speed range is required to identify and lockout any natural frequency vibration levels which may exceed CTI guidelines. Marley Premium VFD System 6.4 Add the following paragraph in the Mechanical Equipment section when VFD is used as a stand alone system: A complete UL listed Variable Speed Drive system in a NEMA 12 indoor or NEMA 3R outdoor enclosure shall be provided. The VFD shall use PWM technology with IGBT switching and integrated bypass design. VFD output switching shall not cause mechanical issues with gearbox teeth or drive shafts. The VFD shall catch a fan spinning in the reverse direction without tripping. The panel shall include a main disconnect with short circuit protection and external operating handle, lockable in the off position for safety. The system shall include a solid state, PI temperature controller to adjust frequency output of the drive in response to the tower fluid temperature. The temperature of the fluid and set point shall be displayed on the door of the control panel. The bypass shall include a complete magnetic bypass

33 Marley / Sigma Steel Cooling Tower / Specifications: Options 23 Specifications Specification Value circuit with capability to isolate the VFD when in the bypass mode. Transfer to the bypass mode shall be automatic in the event of VFD failure or for specific trip conditions allowing safe transfer of utility voltage to the motor. Automatic bypass with an earth ground condition is not allowed. The bypass contactor shall be cycled on and off while operating in bypass, to maintain the set-point temperature of the cold water. The drive design shall be operated as a stand-alone system without the need for a BMS system. Operator controls shall be mounted on the front of the enclosure and shall consist of start and stop control, bypass/ VFD selector switch, Auto/Manual selector switch, manual speed control, and solid-state temperature controller. An emergency bypass selector switch internal to the panel allowing the fluid cooler fan motor to be run at full speed shall be furnished. To prevent heating problems in the fluid cooler fan motor and to assure proper gear box lubrication the VFD system shall de energize the motor once 25% motor speed is reached and cooling is no longer required. The VFD shall include de-icing logic with auto canceling and adjustable time. Speed in De-Ice mode shall not exceed 50% motor speed. The fluid cooler manufacturer shall supply VFD start-up assistance. Tower vibration testing throughout the speed range is required to identify and lockout any natural frequency vibration levels which may exceed CTI guidelines. Vibration Limit Switch: 5.8 Add the following paragraph in the Mechanical Equipment section: A single-pole, double-throw vibration limit switch in a NEMA 4 housing shall be installed on the mechanical equipment support for wiring into the owner s control panel. The purpose of this switch will be to interrupt power to the motor in the event of excessive vibration. It shall be adjustable for sensitivity, and shall require manual reset. Unless specified otherwise, a Marley M-5 vibration switch will be provided. The requirement for manual reset assures that the tower will be visited to determine the cause of excessive vibration.

34 Marley / Sigma Steel Cooling Tower / Specifications: Options 24 Specifications Specification Value Convenience and Safety Options Stairway: 9.3 Replace paragraph 9.3 with the following: A 30" wide, 45 steel stairway with 8" rise and run, shall be provided at the tower endwall rising from grade (roof) to the fan deck elevation. Stair treads shall be bar grating with checker plate nosing, and shall be through bolted to structural channel stringers. Stairway posts, guardrails and toeboards shall be as specified per Paragraph 9.2. Structural steel support columns for the stairway shall be provided by the cooling tower manufacturer. Stairway foundation shall be by others, designed in accordance with drawings provided by the cooling tower manufacturer. The entire stairway shall be hot-dip galvanized after fabrication and shall conform to OSHA standards. Plenum Walkway: 9.1 Add the following to the end of this paragraph: Provide a 30" wide bar grating walkway extending from one endwall access door to the other in each cell. This walkway shall be supported by a galvanized steel framework, and the top of the grating shall be above the cold water basin overflow level. If the cold water basin is deeper than 4'-0", the walkway shall be equipped with guardrails. Ladder Extension: 9.4 Add the following paragraph in the Access and Safety section: Provide a ladder extension for connection to the base of the ladder attached to the tower casing. This extension shall be long enough to rise from the roof (grade) level to the base of the tower. Anchorage and lateral bracing of the ladder extension shall be by others. Ladder Safety Cage: 9.3 Add the following to the end of this paragraph: A heavy gauge galvanized steel safety cage shall surround the ladder, extending from a point approximately 7'-0" above the base of the ladder to the top of the guardrail surrounding the fan deck. Although they are not necessary for routine operation and maintenance, stairways do provide a safe and comfortable means of access to the top of the tower that is often overlooked in the initial cooling tower purchase. They are designed in straight-run or double-back configurations to accommodate your site requirements. This option permits freedom of movement for inspection or maintenance within the tower without the need for wading boots or tower drainage. It also helps prevent maintenance personnel from damaging submerged accessories in the cold water basin (such as screens, probes, basin heaters, etc.). Many towers are installed such that the base of the tower is 2'-0" or more above the roof or grade level. This makes it difficult to get up to the base of the attached ladder. The ladder extension alleviates this problem. Marley ladder extensions are available in standard 5'-0" and 11'-0" lengths, and will be field-cut to fit. To meet OSHA guidelines, towers whose fan decks are 20'-0" or more above roof or grade, and which are equipped with ladders, are required to have safety cages surrounding the ladders.