Underground Duct Advantages, Description & Installation Of .
www.spiralmfg.comUnderground DuctAdvantages, Description & Installation ofUnderground Duct SystemsUnderground DuctInstallationPVS (Polyvinyl Steel) coated underground HVACduct (also known as PCD, PVC coated, andPVCS) is UL listed and specified more often byarchitects, engineers, and contractors than any otherunderground air delivery system because it offersboth the strength of steel and the inertness of plastic.These attributes make PVS ideal for in undergroundas well as corrosive fume exhaustapplications, such as in the platingindustry.How PVS is manufacturedAlthough PVS duct has been used successfullyin underground applications for over 30 years,successful results depend on correct installationprocedures.PVS is manufactured by a three stepprocess: 1) hot-dipped, galvanized G60 steel is cleaned and fire treated; 2) aspecial epoxy primer is baked onto bothsides of the sheet; 3) Finally, a 4 mil.polyvinyl chloride coating is heat fused onto one side(4 x 1) for underground HVAC or onto both sides (4 x4) for chemical fume exhaust applications. The resultis a tough, corrosion resistant surface that will notcrack, chip, peel, or rust.Advantages of underground PVS duct Placing ductwork underground results in a moreaesthetically pleasing interior. Acoustical aestheticsis also improved since most or all of the “rumble”associated with interior duct is significantly reducedor eliminated. The space between the ceiling and roof can bereduced, making it easier to install electrical and firesuppression systems. Installing duct underground allows the air deliverysystem to be designed for optimum efficiencybecause ducts do not have to run through, or parallelto roof supports. In addition, runs inside interior orexterior walls can often be eliminated. Underground duct is a cost effective solution whenair needs to be supplied to adjacent or contiguousbuildings because a central unit can serve alllocations. PVS duct requires no protection from concrete orthe minerals and salts found in backfill. It is strong enough to walk on and will carrymoderate soil loads; yet it can be cut or modifiedon the jobsite with circular or saber saws fitted withmetal cutting blades.35Engineering Considerations: It is always recommended that duct systems–whether above or below grade–bedesigned by a qualified engineer andinstalled by a qualified contractor.When a concrete slab will not coverunderground duct, special considerationmust be given to potential future loadingfrom heavy equipment. If such loadingis expected, PVS duct can be incasedin concrete, in which case the ductwill need to be securely tied downto prevent “floating.” When a concrete slab willcover the duct, loading is not as critical, but it isrecommended that the duct not be buried deeperthan 2.5 times its diameter. At depths greater than2.5 times the diameter, additional measures mustbe taken to insure the duct does not collapse.Such measures include the use of painted angleiron flange connectors for added stiffness at joints,special reinforcing around the duct, or (on ducts 36”or larger) internal reinforcement. Consult a qualifiedengineer when such measures are required or whenthere is any concern about loading.Preparing the sub grade: PVS duct can be placed directly on the soil with nospecial precautions to protect the duct. However,drainage needs to be considered because standingwater may eventually find its way into the ductcausing mold and odor problems. The grade shouldalways be sloped back to the utility room, and neverplace PVS duct at or below the water table. It is recommeded that the duct be placed on 2”to 6” of pea gravel or other material that will permiteasy drainage, especially when soil conditions aremarginal. (Although not required to protect the duct,a vapor barrier should be placed under the ductand below the entire slab to prevent moisture frompercolating through the concrete.)11419 Yellowpine Street N.W. Minneapolis, MN 55448-3158Phone: 763-755-7677 800-426-3643 Fax: 763-755-6184
Underground DuctConnecting, Fastening & BackfillingConnecting and fastening:Table 36-1: Load SpecificationsPVS Duct and fittings (or connectors) have male andfemale ends, respectively, and they are designed to sliptogether. Before joining, PVC sealant must be appliedto the outside of the female fitting (or connector) andthe inside of the duct. The joint must then be fastenedaround its circumference with sheet metal screwsspaced no more than 6” apart and with a minimum ofthree screws per joint. Sealant should then be appliedto the joint’s edge and to screw heads. After the sealanthas cured, the joint should be wrapped with two to threelayers of PVC tape.Spot surface repair:Max. Loading(lbs./linear ft.)8” or less*4009” to 13–1/2”*60014” to 36”**1800*Uncorrugated **CorrugatedAll ducts 14” or larger are corrugated for underground applications. Loading specifications for ducts larger than 36” have notbeen determined.Corrugated Lateral Section(diameters 14” and above)(Interior Side)The plastic surface of PVS duct is exceptionally tough,but it can be scratched. When scratches expose baremetal, they should be sealed with PVC tape or PVCTouch-Up Paint spray. Having these remedies available atthe jobsite helps to assure that this detail is not neglected.Backfilling:After the duct has been placed, spread backfill evenly inseveral layers (depending on the diameter of the pipe) andtamp each layer. Tamping should be done carefully toavoid denting or scratching the pipe’s surface; do not usemechanical tampers since their shockwaves can severlydamage the duct. Do not toss backfill directly on the ductsince this may cause denting, scratching, or even collapseif a large weight of fill is dumped directly onto the pipe.Similar care should be taken if concrete is being used toencase the duct.SLABDiameter(inches)411/16”Standard Lateral Section(diameters 4” to 131/2”)(Interior Side)411/16”Precautions and limits:Sheet metal duct is flexible, not rigid, so greatercare must be taken when installing PVS duct.Three parameters need to be considered:External load (soil load point load), soil stiffness(modulus), and pipe stiffness. In the absence oftest data, a soil modulus of 200 PSI and a soildensity of 120 lbs/ft3 can be used in calculations.Consult with an engineer. PVS TemperatureLimits: Operating temperatures for PVS range from-40 F to 250 F, with limited exposure to 400 F.OPTIONALREGISTER VAPOR BATTIERBACKFILLFOUNDATIONPVSDUCTGRADE LINESOILPOROUS FILLWATER TABLEThe duct, encased either in concrete or burieddirectly below a concrete slab, is installed above theoriginal line of undisturbed soil and above the watertable. Encasing the duct in concrete with porous fillbeneath is the best way to install PVS duct. An optionalvapor barrier can be placed between the pipe and thefill. Always consult local building codes for specificinstallation instructions.Spiral Manufacturing Co., Inc. offers a broad lineof Class 1 PVS Spiral pipe and fittings. We buildcustom made fittings and hoods on request toaccompany our standard product line. Our PVSproducts comply with the following codes andindustry standards:UL 181 Class 1International Mechanical Code 1996 Section 603ICBO Uniform Mechanical Code - (UMC) 1997SMACNA Sheet Metal Air ConditioningContractors National Association36
www.spiralmfg.comLow PressureA complete line of low pressure duct &fittings — in stock and availableThe terms “low” pressure and “high” pressure induct design and selection have, unfortunately,been given a rather wide latitude of meaningsin the HVAC industry over the years. The termshave been applied to “pressure” and “velocity”simultaneously because they are interdependant in ductwork design. This sectionof the catalog is devoted to the definition andselection of “low” pressure equipment andcomponents.the “High Pressure” manual, but their respectivedesigns have been based on historicalacceptability.Table 37-1: Pressure Velocity Classification 1FormerDuctClassThe dividing line for “velocity” of air in ductshas been defined in various applications asanywhere from 1500 to 2500 fpm and nominallyas 2000 fpm. Empirical data has shown thatduct sections operate satisfactorily over theabove range of velocities at 1 water gage ( wg).Low pressure systems are chosen where ductspace allows, where air noise is a consideration,and where particle conveyance such as woodchips or grain is not a requirement.Space limitations in modern buildings haverestricted the size of air conditioning ductsand equipment. Therefore, to convey thenecessary volumes of air, higher velocities mustbe employed. Increased velocities producehigher duct friction losses. In order to maintainflow against the higher duct friction, it isnecessary to have greater pressures at the airsource. Therefore, the terms “high pressure”and “high velocity” generally go hand in hand.Conversely, this is true of “low pressure” and“low ty(fpm)3HighPres.10”Pos.A2000 UpMediumPres.6”Pos.A2000 UpMediumPres.4”Pos.A2000 UpMediumPres.3”Pos. orNeg.A4000 DnLowPres.2”Pos. orNeg.2000 DnLowPres.1”Pos. orNeg.2000 DnLowPres.½”Pos. orNeg.1500 Dn1Reproduced in part by Permission From SMACNA High PressureDuct Standards - 3rd Ed.2Seal Class A: All seams, joints, fastener penetrations andconnections sealed.3General velocity level through this pressure rated section ofthe system. Certain points may have higher or lower velocities,e.g., fan outlet or restricted passage, yet not require a differentpressure class. The designer makes determinations of duct classafter analyzing velocities and operating pressures.The use of the terms “high velocity” and “highand medium pressure” in this catalog refer toany static pressure class of 3 wg or greater,and “low pressure” refers to 2 wg or less.SMACNA recommendations on pressure andvelocity are shown in Table 37-1. The listedclassifications pertain to ducts only. Casingand plenum construction designs are providedin the SMACNA “Low Pressure” manual and in37Spiral Manufacturing stocks a complete line of lowpressure fittings and installation accessories.11419 Yellowpine Street N.W. Minneapolis, MN 55448-3158Phone: 763-755-7677 800-426-3643 Fax: 763-755-6184
A complete line of low pressure duct &fittings. Custom fittings availableLow PressureAdjustable ElbowsConcentric ReducerShoe Tap90 Angle Boot (PVS)Loop Head Saddle (PVS)Register End Boot (PVS)Conical Takeoff *Air Intake HoodCanvas ConnectionsAirflow Takeoff (HET) *45 Register Saddle (PVS)Starting Collar withdamper* Preinstalled Peel n’ Stick gasket.Available with or without damper.38
www.spiralmfg.comDust CollectionThe importance of dust collection & choosing the right type of duct for dust collectionWhy you need a dust collection systemInstalling an efficient dust collection systemshould be a priority for the small shop as wellas the large shop, whether the material beingmachined is wood, plastic, or a composite. Notonly is this essential for health reasons andcompliance with many national and local codes,but it is also good business because it savesmoney and helps to maintain the quality of thefinished product.The harmful health effects of inhaledparticulates (many of which are carcinogens)are well documented, and skin, eye, andnose problems as well as allergic reactionsare frequently reported. In addition, a dustyshop increases the risk of worker injury andfire, which can result in lost production, higherinsurance rates, and lawsuits.A dusty shop compromises the quality of thefinished product: Accurate measurements andcuts are more difficult due to lack of visibility;airborne dust finds its way into finishing areascausing defects in the final product; and largerparticles cling to surfaces cause scoring andother defects.Finally, dust that is not automatically collectedmust be collected manually as a recurring directlabor expense.By any measure, an efficient dust collectionsystem is an investment that more than pays foritself.Designing a dust collection systemIn the simplest terms, a dust collection systemis comprised of a ducting system to transportthe dust from the source (table saw, planer,etc.) and a collection device (such as a bag andfilter system or a cyclone), which pulls the dustthrough the ducting and collects it. The veryfirst decision you must make is whether yourducting will be metal or plastic—and here thereis only one logical choice: metal. (See “Metal39vs. Plastic Duct” below.) The next step is to sizeyour system. (See “Designing Your System” onpages 41-44.)Metal vs. Plastic DuctPlastic pipe (or PVC pipe) is unsuitable fordust collection for three reasons: First, plastic pipe fittings are not offeredin the diversity required to meet designrequirements. Second, plastic pipe elbows have ashort radius, which encourages clogs andcompromises system efficiency. Third, and most important, plastic pipeis non-conductive and builds up a staticcharge as charged particles pass throughit. This static charge can discharge at anytime causing shock and surprise, whichis dangerous around running machinery.More serious is the risk of explosion andfire. Fine dust particles suspended in airhave significant explosion potential—allthat is needed is a spark, which the staticcharge on plastic pipe conveniently supplies.Grounding plastic pipe requires wrapping itin wire both inside and out—an expensive(and never certain) proposition that negatesthe minimal price savings in going to plasticin the first place.Spiral steel pipe has none of thesedisadvantages. An incredible variety offittings are available and custom fittingscan be easily fabricated. The fittings aredesigned with long radius to minimizeclogging, and special fittings such as cleanouts and quick disconnects are available.Most important, Spiral metal pipe isconductive, and simple and easy to ground,even when flexible rubber hose is used toconnect the duct to the machine.11419 Yellowpine Street N.W. Minneapolis, MN 55448-3158Phone: 763-755-7677 800-426-3643 Fax: 763-755-6184
Standard dust collection components& accessoriesDust CollectionSpiral Manufacturing has all the duct components you need to designand build a safe and efficient dust collection systemLaterals (Pages 12-14)Reducers (Page 15)Elbows (Pages 5-6)Blast Gates (Pages 31-32)Clean-outs (Page 30)Floor Sweeps (Page 17)Clear Flex Hose (Page 33)Manifolds (Page 14)Custom Hoods (Page19)Clamps (Page 34)Bellmouth (Page 17)Duct Sealants (Page 27)40
www.spiralmfg.comDust CollectionHow to design an efficient dust collectionsystem with Spiral pipe.Designing Your SystemThere are two phases to designing your dust collection system:The first phase is sizing your duct work for adequate volume andvelocity of flow for the type of dust you will be creating; and thesecond phase is computing the static pressure (SP) of your systemto determine the size and power of your dust collection unit.Step 2Determine the diameter of each branch line. You can use thediameter of a factory installed collar or port, or consult themanufacturer. Convert metric ports to the nearest inch. Convertrectangular ports to the equivalent round diameter. Ports less than3” will require a reducer to 4”. Record any reducers or rectangularto round transitions on your take off list.Prior to making your calculations, diagram the floor plan of yourshop to scale on graph paper. Include the size and location of eachmachine, and the location of its dust port or outlet; the floor to joistdimension; the location of the dust collecting unit; and the mostefficient (fewest number of turns or bends) path for routing yourduct lines. This is also a good time to start your take-off list of ductcomponents for your system.Step 3Using Table 41-2, determine the CFM requirement of each branch.Remember the FPM for wood dust in branch lines is 4500.Example: Table saw4” dia.390 CFM (rounded)Planer5” dia.610 CFM (rounded)Lathe6” dia.880 CFM (rounded)Continue for all branches.You will also need to familiarize yourself with the followingconcepts:CFM (Cubic Feet per Minute) is the volume of air moved per minute.FPM (Feet per Minute) is the velocity of the airstream.SP (Static Pressure) is defined as the pressure in the duct that tendsto burst or collapse the duct and is expressed in inches of watergage ( wg).VP (Velocity Pressure), expressed in inches of water gage ( wg), isthe pressure in the direction of flow required to move air at rest toa given velocity.Table 41-2: CFM for for pipe diameter at specified velocityDiameter3500 FPM4000 FPM4500 810CFM is related to FPM by the formula CFM FPM x cross-sectionalarea (ft2). FPM is important because a minimum FPM is requiredto keep particles entrained in the air stream. Below this minmumFPM, particles will begin to settle out of the air stream, formingclogs—especially in vertical runs. Table 41-1 shows the minimumFPM that Spiral Manufacturing recommends for several types ofdust in branch and main runs.Step 1From the Table 41-1 determine the velocity (FPM) of your systemfor the type of dust that will be produced. For the purpose ofthe following examples assume woodworking dust. Wood dustrequires 4500 FPM in branches and 4000 FPM in mains.For larger diameters see pages 59-60.Step 4Identify your primary or high-use machines. These are the machinesthat operate simultaneously on a frequent basis. The objective hereis to define your heaviest use scenario so you can size your systemto meet it. Including infrequently used machines and floor pickups in your calculations will only result in an over-designed systemthat will cost more to purchase and to operate. At this point, all ofyour branch lines are sized, and you have a list of all componentsrequired for your branch lines.Table 41-1: Velocity for Type of DustType of DustVelocityin Branches(FPM)Velocityin Main(FPM)Metalworking Dust50004500Woodworking Dust45004000Plastic/OtherLight Dust4500Step 5Now you are ready to size the main trunk line. Begin with theprimary machine that is furthest from where you will place the dust4000Figure 41-1Floor 5 Reducing Lateral90 Elbow10‘5 Ø4 Ø7 ØTable Saw(Primary)6‘12‘15‘8‘10 Ø10 ØRadial Arm Saw45 Standard Lateral45 ElbowSander6‘Floor Pick-Up4111419 Yellowpine Street N.W. Minneapolis, MN 55448-3158Phone: 763-755-7677 800-426-3643 Fax: 763-755-6184
How to design an efficient dust collectionsystem with spiral pipe.collecting unit. In our example, this is the table saw, which has abranch diameter of 4”. Run this 4 Spiral pipe to the point wherethe second primary machine (the planer on a 5 branch) will enterthe main. (Note: If a non-primary machine or pick-up is added tothe system between primary machines, the size of the run is notincreased.)You now have a 390 CFM line (table saw) and a 610 CFM line(planer) combining for a total of 1000 CFM. Using Table 41-2again, you will see that for 4000 FPM (the velocity requirement formain line that you determined in Step 1) the required pipe diameterfalls between 6” and 7”. (Note: Spiral Manufacturung recommendsthat you round up to 7”. This not only assures adequate air flowbut also anticipates a future upgrade in machine size.)Now calculate for the addition of the third primary machine (thelathe on a 6 branch). You have an 1000 CFM main an 880 CFMbranch line (for the lathe) for a total of 1880 CFM. Using Table41-2 once again, 1880 CFM at 4000 FPM requires between a 9”and 10” pipe. We recommed rounding up to a 10” main afterthe addition of the lathe. The main going to your dust collectingunit will be 10”, and your dust collection unit must be capable ofpulling 1880 CFM through a 10” duct at 4000 FPM.Step 6Dust CollectionFigure 42-22) Calculate the SP of the main:In our example the main has one 8’ run of 7” Spiral pipe, tworuns (15’ and 12’) of 10”
Underground Duct PVS (Polyvinyl Steel) coated underground HVAC duct (also known as PCD, PVC coated, and PVCS) is UL listed and specifi ed more often by architects, engineers, and contractors than any other underground air delivery system because it offers both the strength of steel and the inertness of plastic.
installed as described in the TDC or TDF addendum to the SMACNA Duct Construction Standards except the corners may not be bolted. Standard 5" metal clips may be used with spacing as shown in diagram. SLEEVE DUCT TYPICAL TDC/TDF JOINT DUCT 60" Duct 3 REQ'D. 48" Duct 3 REQ'D. 36" Duct 3 REQ'D. 24" Duct 2 REQ'D. 18" DUCT and .
Duct Sizing Tools OR Duct Sizing Chart Ductulator (Manual/Digital) AIRAH DA3 Duct Design Manual Manufacturers/Programs . Duct Sizing Methods . More available in the ASHRAE Handbook or SMACNA Obtain other duct fittings pressure losses from manufacturers such as duct heaters, dampers, filters, grilles, coils, etc
Air Duct Design & Sizing Duct sizing methods Static regain method Normally used with a computer package for high velocity systems (e.g. in main duct) Size air duct so that static pressure nearly offset the pressure loss of succeeding duct section along main duct T me
Under Floor Duct 1.5 OFFSET FOR #6 DUCT PU6-OFS15 Duct / Under Floor Duct. L 4 International Drive Rye Brook, NY 10573 Toll Free: 1 888.764.7681 Phone: 914.934.2075 Fax: 914.934.2190 MonoSystems.com 03/2016 DOCUMENT REF. NO. PU6FFL45-PU6WE Manufactured by MonoSystems, Inc. Under Floor Duct
lsc bus duct system 1. introduction 3 1.1 general specifications 1.2 outstanding feature of lsc bus duct 1.3 cataloging 2. high power distribution (600a 6000a) 9 2.1 general specifications 2.1.1 i-series bus duct 2.1.2 8-series bus duct 2.1.3 f-series bus duct 2.1.4 y-series bus duct 2.2 grounding & ip degree 2.2.1 grounding 2.2.2 ip degree 2.3 .
Catalogue - 06 GALVANIZED PIPE & FITTINGS GALVANIZED DUT 4' SE TION MODEL DESCRIPTION PRICE GV1214 8" x 8" Rectangular Duct 30GA 21.64 GV1215 8" x 10" Rectangular Duct 30GA 22.47 GV1216 8" x 12" Rectangular Duct 30GA 23.31 GV1217 8" x 14" Rectangular Duct 30GA 24.14 GV1218 8" x 16" Rectangular Duct 30GA 24.97
Underground ducts 22 - 23 Underground Direct Burial 24 - 25 In Air 34 In Conduit 37 Triplexed Conductors Underground Ducts 26 - 27 Underground Direct Burial 28 - 29 In Air 35 In Conduit 37 Three Conductor Underground Ducts 30 - 31 Underground Direct Burial 32 - 33 In Air 36 In Conduit 38 N.E.C. Code Table 38 SECTION 7 Installation Practices 39 - 51
Architectural Drafting Line Work Arrowheads are drawn freehand. The length of an arrowhead is the same dimension used for the height of lettering. The proportion of the length of the arrowhead to the width is 3:1 respectively. Arrowheads can be either open, closed, solid, or the traditional slash as shown. Other types of symbols can be used in place of the arrowhead or slash. These include .
