Question: My duct pipe is all 5' feet long, what if I need a 36” piece? (back to top) Answer: Please refer to page 36 of the Technical and Specification Manual. The Adjustable Nipple is a part that is used to make on-site adjustments and odd-sized straight lengths. You cut a straight pipe to the length you need, plus four (4) inches. You then insert the cut pipe into the nipple until the assembled piece is the exact length you need. You use the provided O-ring to secure the cut pipe in place and clamp it to the nipple.
Question: What is Quick Fit/EZ Fit? (back to top) Answer: “Quick Fit” is a trade name used by the manufacturer, Nordfab of Thomasville, North Carolina. It describes the assembly system used to clamp-together the various parts in a project. This assembly system is comprised of the clamp and mechanically rolled edges at the end of each part. Because all of the parts are assembled using a single-throw, lever clamp it is much “quicker” than the traditional flanged ducting that require the tightening of hundreds or even thousands of nuts and bolts. “EZ Fit” is Duct Monkey’s proprietary adaptation of this name.
Question: What other options do I have if I don't have an existing QF system or I won't be connecting to a QF system? (back to top) Answer: Duct Monkey offers many options for you to adapt to an existing system and other “ends” to their fittings which are not “QF” or “EZ Fit”. You may specify no fitting at all by specifying a “raw” interior dimension/diameter (RAW ID) or “raw” outside dimension/diameter (RAW OD). If the part is going to fit INTO another part, specify RAW OD. If the part is going be fit OVER another part, specify RAW ID. If a round end is going to be attached to a hose, specify RAWFLEX. This will give you an end with a raised bead around the edge so the hose will fit tightly around it. If you will need a standard angle flange around the end, specify “Angle Flange”. If you require a specific size flange or a special bolt hole pattern, specify “Flat Flange”. Further down in this section you will find an explanation of the difference between an Angle Flange and a Flat Flange.
Question: What is the adjustable nipple? (back to top) Answer: This part is the key to the Quick-Fit, clamp-together ducting system. It allows you to make custom adjustments on site without requiring special lengths or pieces. It is eleven (11) inches long with the “QF” rolled-edge on both ends. See Page 36 of the Technical and Specification Manual on how to use it.
Question: How many adjustable nipples do I need to order? (back to top) Answer: That really depends on how many changes of elevation and direction you will have in your ducting layout. As a general rule, you should order one piece for each machine drop, one piece for each branch and one piece for each 90º elbow. This will allow you to make vertical and horizontal changes as needed during the installation.
Question: Do the duct clamps come with the pipe? If not how many do I need to order? (back to top) Answer: Clamps do not come with the duct pipe. As a rule you will need one clamp per duct component ordered of each diameter..
Question: What items do you stock? (back to top) Answer: Duct Monkey stocks a wide variety of duct pipes, duct nipples, duct elbows, duct branches, and duct adapters in sizes 3” to 12”. Please call if you need assistance.
Question: How long will it take to receive my order? (back to top) Answer: Standard shipping lead time is 3 to 4 days after you’ve placed the order. Custom items, stainless steel and other specialty parts may take up to 4 weeks to ship. Call us if you require additional information.
Question: What is the pipe bracing for? (back to top) Answer: Pipe bracing is used to support the duct pipe to a wall or ceiling. See the Duct Monkey Technical and Specification Manual for details.
Question: How many hangers do I need per feet of ducting? (back to top) Answer: As a general rule, you only need one hanger at every fifteen (15) feet. However, you should also consider a hanger at each branch and at each 90º elbow to support the additional weight.
Question: How do I connect to the end of an existing (non-QF) ducting system? (back to top) Answer: Duct Monkey offers a full line of duct adapters to connect to any existing duct pipe you might have.
Question: How do I connect the duct to a metric machine? (back to top) Answer: Duct Monkey can make adapters and reducers to connect to most metric machines.
Question: How do I connect to a 2” diameter or smaller machine connection? (back to top) Answer: Duct Monkey offers reducers to 2” diameters and smaller hose connections.
Question: What do I do when I need to connect to a machine that has many parts of different sizes, and they are too close together to use branches? (back to top) Answer: Duct Monkey can make custom duct manifolds to fit your needs. Contact Duct Monkey with your specifications.
Question: What are the exact OD and ID of your pipe? (back to top) Answer: There is a complete listing pipe dimensions in the Duct Monkey catalog, in the machine adapter section and Technical and Specification Manual. You can find the Catalog and Manual on the left hand side of the Home page in our website.
Question: When do I need Gore-Tex clamps? (back to top) Answer: Gore-Tex clamps are typically used in FDA-regulated, chemical, and high temperature applications.
Question: Do I need to do anything different for a “wet” system? (back to top) Answer: Yes. You should contact Duct Monkey with your “wet” system needs. Also see page 34 of the Technical and Specification Manual for recommendations on a “typical” wet system installation.
Question: What is the difference between rigid and ultra-flex steel hose? (back to top) Answer: Rigid flex hose is constructed to hold its form and it is not very flexible, whereas ultra-flex is very flexible, almost like a slinky.
Question: When do I need to use stainless steel? (back to top) Answer: Stainless steel is typically used in FDA-regulated, chemical and high temperature applications.
Question: How much pressure will this pipe withstand? (back to top) Answer: The manufacturer has tested pipe up to 80” WG in constant pressure and vacuum, which was the maximum capacity of the testing equipment. These were not “independent” or “certified” tests. There are currently operating systems with our products that run at vacuums of -32 to -42 WG under normal parameters. See pages 9 and 10 of the Technical and Specifications Manual for additional information on the structural integrity of these products.
Question: What is the difference in “press-formed”, “segmented", “gored”, “LSB”, and “tubed” elbows? (back to top) Answer: Press formed duct elbows are constructed in two halves with a welded seam. Segmented or gored elbows are fabricated using 15 degree increments of laser welded ducting to form the deviation length. LSB.(Lapped Seam and Buffed) elbows are constructed of 16 gauge material segments lapped over one another, spot welded and buffed smooth on the interior. Tubed duct elbows are constructed from a 14 gauge extruded steel tube with QF ends spot welded to each end.
Question: Is QF FDA approved? (back to top) Answer: Duct Monkey duct products are not specifically FDA approved. However, they have been used in many food and pharmaceutical applications and have successfully met and passed FDA requirements and inspections.
Question: Do you offer “clean outs”? (back to top) Answer: Duct Monkey does offer duct clean out doors, please contact Duct Monkey for details. We do not recommend them due to them being a potential point of clog themselves. With the removal of (2) duct clamps on any component you have the equivalent of a clean out door.
Question: Is QF SMACNA certified? (back to top) Answer: Duct Monkey is not SMACNA certified, although Duct Monkey does meet and exceed standards for Class 2 Ducting.
Question: What is the difference between “angle flange” and “flat flange”? (back to top) Answer: Angle flanges are typically fabricated from steel angle form which is rolled into a ring and welded. They are then drilled and hot-dipped galvanized. The bolt-hole pattern is the suggested pattern for 150-pound flanges per ANSI standards. This flange is our standard for all flanged fittings and the individual angle flanges (part # 3261). Flat flanges are cut to your specifications from 3/16” thick galvanized sheet metal. They are not drilled unless a bolt-hole pattern is provided.
Question: What is CFM? and how does it relate to pipe? (back to top) Answer: CFM stands for “cubic feet per minute” and it is the measurement for the movement of the volume of air within a confined space at a specified velocity. Within a specified diameter duct, the higher the velocity the air is moved, the greater the volume of air being transported. By the same token, if volume is increased but not duct diameter, then you will have a drop in velocity. There is a point where increased volume begins to cause decreased velocities within a specified diameter of duct. Therefore, in order to maintain a “recommended” velocity within a ducting system, adjustments need to be made in the ducting size so that changes in volume do not adversely affect this factor.
Question: What is FPM? and how does it relate to pipe? (back to top) Answer: FPM stands for “feet per minute” and it is the measurement of the speed (or velocity) at which air is moving. Typically, is it used to gauge the velocity of air movement within a confined space, such as ducting. This measurement is important especially as a function of transporting material within an air stream. Like a tornado or a hurricane, the higher the air speeds in the storm the bigger the things that get moved by them. Small particles of dust, gases or fumes do not require much velocity to move them. Heavier or bigger particles, like wood chips, metal filings or wet dusts require higher velocities. See page 45 of our Technical Manual for a chart of recommended velocities to transport different types of dusts.
Question: If velocity is so important, why not run a system at the highest available velocity? (back to top) Answer: Velocity within a ducting system is regulated by the fan that generates the air stream; whether in a “positive” or “pushing” direction, such as air conditioning fans, or a “negative” or “vacuum” direction, such as in dust collection systems. This speed is primarily regulated by the number of revolutions per minute (“RPM”) the fan is turning as well as the physical size of the fan. To run at higher RPM’s you need a bigger motor. This, in turn, means higher power consumption; a costly proposition regardless of the power source. The idea is to run a fan at just enough RPM’s to generate just enough velocity to keep the required volume of air within the system moving at this minimum speed.
Question: What other factors, in addition to velocity, are affected if you increase the CFM in a specific duct size? (back to top) Answer: As you increase the volume of air flowing through a duct, it exerts pressure towards the outside of the duct (in positive systems) or “pulls” the ducting material towards the inside (in negative systems). The difference in pressure between the ambient air outside the ducting (usually stated as zero) and the positive or negative pressure inside the ducting is called “static pressure” and is expressed in inches of water gauge (positive or negative). At a high enough pressure differential, the ducting will either burst (in positive systems) or collapse (in negative systems). Systems working at high static pressures require higher velocities to move the increased volume. Higher static pressures could also increase the amount of abrasion inside the ducting, depending on the material being transported.
Question: What QF diameter components does Duct Monkey offer? (back to top) Answer: Duct Monkey offers 3”-24” diameter duct components with the QF clamped-together ends. In diameters 24” and greater, all the components have angle flange ends and are bolted together.
Question: What is the “CLR” on an elbow; what does is mean? (back to top) Answer: CLR stands for “centerline radius” and is stated as a factor of the diameter of the elbow. Think in terms of a circle; the rate at which the circle is turning is called the radius – smaller and tighter circles have smaller radii, larger circles have bigger radii. If you cut a circle in four equal parts (each part having 90º), the distance traveled around the circle by one of those parts is called the arc. In ducting elbows, the arc AND radius are stated as ratios of the diameter. So, a 4” 90º elbow with 1.5 CLR will have an “arc” (down the center of the elbow) of 6” (4 x 1.5 = 6) – the elbow is approximately 6” long. The same elbow with a 2.5 CLR will have an arc of 10” (4 x 2.5 = 10) – this 4” 90º elbow is 10” long. What this also means is that the “sweep” or severity of the bend is tighter on the smaller CLR elbow.
Question: What factors should I consider when deciding on the CLR of the elbows I need? (back to top) Answer: In general, there are only two factors that would require a different CLR than that offered as standard: 1) Space constraints (you’re making a turn in a tight space) or 2) Highly abrasive applications (the material being transported will cause extreme wear on the inside of the elbow). Elbows with longer “sweeps” (or higher CLR) allow the air to be re-directed inside the elbow in a less severe fashion, thus reducing the severity of the “rub” on the inside. The movement of air across the surface causes friction and this is the friction that wears out the material. This same friction also slows down the air velocity (called “friction loss”). So an additional factor to consider when deciding what the CLR of the elbows should be is how many bends you will need to make. The more bends you need to make (beyond a typical of say 4 or 5 in a smaller system), the higher the CLR of the elbows so as to reduce the friction and resulting velocity loss.
Question: How much CFM do you use when calculating for a 4” Floor Sweep? (back to top) Answer: When calculating the CFM added to a system for any diameter floor sweep you use 0 CFM.
Question: What is the rule of thumb for determining what standard branches (part # 3210) we can make? (back to top) Answer: Sometimes, machine layouts are such that as you go down the main line back to the collector a branch is required that is not possible to fabricate. For example, let’s say you have three machines in a production line. The furthest away from the dust collector requires a 4” duct, the one in the middle requires a 10” duct and the one closest to the collector requires another 4” duct. The middle branch will probably require a configuration of say A= 12”, B= 10” and C= 4”, where A is the outlet to the mainline, B is the “drop” to the middle machine and C is the continuation to the last machine (that is our standard way of sizing these branches). The 10” duct will be too big to place on a tapering duct from 12” to 4” – it won’t fit. The solution is to order a 12”-10”-10” branch with a 10” to 4” Reducer. The quickest way to calculate what can be “fabricated” is expressed in the formula “A – B has to be greater than or equal to B – C“. In the example above, A – B = 2” and B – C = 6” so this branch cannot be fabricated with those diameters.
Question: Why is it important to not make right angle penetrations when building duct branch fittings? (back to top) Answer: Air, like water, is not real cooperative when asked to make severe turns in its flow. An “L” shaped, 90º (right angle) turn is one of the most severe forms of flow deviations that can be incorporated into a ducting system design. Air tends to bounce around in this location (causing “vortexes” and “turbulence”) which takes a bit of time and increased velocity to “straighten” out. This results in much increased static pressures and friction at this location in addition to increasing inefficiency. It is recommended that branch fittings be made at a 30º angles. Our standard branch fittings are at this angle of deviation.
Question: Why is it important to not have interior ledges or voids when fabricating dust system fittings? (back to top) Answer: Any snags, cracks, and ledges can cause clogs or build up which will cause friction and decrease air flow.
Question: What diameter range is Duct Monkey's full ducting product line? (back to top) Answer: Duct Monkey manufactures duct from 3” to 40” diameter.
Question: What types of metal does Duct Monkey offer? (back to top) Answer: Duct Monkey offers Galvanized Steel, Aluminum, and Stainless Steel Duct.
Question: What typical types of applications require Stainless Steel duct pipe? (back to top) Answer: Food, high temperature, pharmaceutical, some fumes and gases, some chemicals, or any application that requires frequent wash down of the ducting parts.
Question: What is the difference between a corrosive material and an abrasive material? (back to top) Answer: Corrosive material corrodes or “eats” through material whereas abrasive material wears or “rubs” through material. There are some “wet” applications that can have both characteristics. In those instances, please contact us for specific recommendations.
Question: What is the maximum temperature rating for Galvanized duct metal? (back to top) Answer: Maximum temperature rating for galvanized duct metal is 500 degrees Fahrenheit.
Question: What is the rule of thumb to estimate the length of a standard branch (part #3210)? (back to top) Answer: Typically the length of a standard branch can be figured by the following formula; B (or lateral) diameter x 2 + 9”.
Question: What types of seal material does Duct Monkey offer in their duct clamps? (back to top) Answer: Nitrile rubber is the standard and Gortex for food, high temperature and chemical applications.
Question: What is the maximum temperature rating on Stainless Steel ducting? (back to top) Answer: Maximum temperature rating for stainless steel metal duct is 800 degrees Fahrenheit. Above 800 F. to 1,100 F. there is no metal degradation but a small amount of bluing may occur.
Question: What is the standard length and shortest length a smooth transitioning rectangular (or square) to round transition can be made? (back to top) Answer: The default length on a smooth transition is the longest dimension of the rectangle whereas the shortest a smooth transitioning rectangular to round can be made is 75% of the longest rectangular side.
Question: What is the difference between the two types of O-rings offered by Duct Monkey? (back to top) Answer: Black (or Nitrile) rubber is the standard and can be used in most applications. Red (Silicon) are ordered separately, used instead of the provided black rubber and are required for FDA-regulated applications. Red O-rings should also be used instead of the black in high temperature (below -40 degrees Fahrenheit or above 250 degrees F.) applications.
Question: What is Duct Monkey's return policy? (back to top) Answer: STOCK ITEMS are returnable within 90 days of receipt of order. An itemized list with part number and sales order number (or purchase order number) is requested to issue a return good authorization. Once this authorization is sent, the goods may be returned to the indicated location. The customer is responsible for the payment of freight. There will be a 25% restocking fee subtracted from the credit to be issued to the customer after inspection of the returned items. Items must be in re-sellable condition. CUSTOM ITEM SALES ARE FINAL AND NON-RETURNABLE.
Question: What is the heaviest metal-gauge duct that can be manufactured with the QF rolled edge (clamp-together)? (back to top) Answer: Currently the heaviest-gauge ducting that can be manufactured with QF ends is 18 gauge.
Question: What are the temperature ratings for Duct Monkey's duct clamp seals? (back to top) Answer: Nitrile (standard) rubber seals are rated for maximum temperature of -104 degrees Fahrenheit to +158 degrees F. with an intermittent maximum temperate of +194 degrees F. Gortex seals are rated for -450 degrees F. to +600 degrees F.
Question: What QF products would be suitable for food-grade applications? (back to top) Answer: Stainless steel duct pipe and duct fittings w/Gortex seals in duct clamps, red silicon adjustable nipple O-rings as well as clear rubber hose.
Question: What important features do most food-grade users look for in specifying pipe? (back to top) Answer: No possible “bug harbors”, cracks, leaks, or ledges.
Question: Maximum temperature rating for Duct Monkey's standard caulk and high temperature caulk? (back to top) Answer: Standard caulk is rated for temperatures between 0-250 degrees F. High temperature caulk is rated for temperatures between 250-500 degrees F. Caulk is used to seal joints in elbows and other fittings. It is used instead of the traditional “full weld” option; it is just as effective but less expensive.
Question: What is the up charge for fully caulked product? (back to top) Answer: Up charge for fully caulked products is 10% of the listed price.
Question: When fully caulked items are requested, which Duct Monkey items need to be fully caulked? (back to top) Answer: Duct Monkey items that need to be fully caulked when requested are transitions, branches, reducers, LSB elbows, in-cut, tap-ins, diverter values, and pressed formed elbows.
