In most circumstances, metal that is used for pipe fabrication needs to be heated before it can be bent into shape. However, there are some instances when heating metal isn’t an option. Some metals can be bent cold if the right process is used. It isn’t recommended for certain metals such as brass as it can cause them to crack or even shatter. In addition, it isn’t recommended for smaller bends since it can cause smaller bends to kink. Most of the time, cold bending is used for pipes or tubes that require larger bends.

Roll Bending

Cold bending is also known as roll bending because of the process most commonly used to bend metal that hasn’t been heated. Roll bending is accomplished using a mechanical jig that uses three rollers to bend metal into a circular arc. The two outer rollers are usually immobile and are used to hold the metal in place, while the third roller places pressure on top of the metal, creating the large bend that is needed for the project. The process is particularly useful when bending sheet metal. Bending pipes and tubes in this way is more difficult, but it can be done.

Other Cold Bending Methods

Cold bending can also be done through other methods, although it isn’t always recommended. Bending metal that hasn’t been heated is as difficult as it sounds, and there’s a reason why most professional companies use roll benders. However, cold bending metal is possible with a vise and a pair of tongs. The metal is held tightly in place by the vise, and the tongs are used to grip and bend the metal. Alternatively, some metalworkers like to bend sheet metal or rods around an anvil. Neither method provides as smooth or precise a bend as roll bending, but they are also used when it isn’t possible to bend heated metal. For the best results, cold bending is the way to go.

Why Cold Bending is Necessary

Cold bending, particularly when it is done using a roll bender, can be used when there is no way to heat metal before it can be bent. It is also utilized when it is necessary to have a large, smooth bend in a pipe or with sheet metal. Pipes in particular, need to be have gentler curves in order to accommodate water or other fluids that may pass through them, and cold bending is sometimes the only way to create these curves and large bends. Cold bending is also cheaper in many cases; the equipment and materials needed to work with heated metal are expensive. By working with cold metal whenever possible, pipe fabricators and metal workers can save on production costs. Finally, some metalworkers find that cold bending creates more aesthetically pleasing final products, with smoother finishes and gentler curves that often aren’t possible through other methods.

In general, working with heated metal is much easier than cold metal, and it is usually the preferred method for most metalworkers. However, those who want to create large bends with gentler curves when fabricating pipes or bending sheet metal find that cold bending is often necessary.

There are countless reasons that pipes might need to be bent. Whether they are simply wrapping around a corner or they are required to coil in order to cool the gas or liquid that flows through them, pipe bending is an important service offered to those who require it. Though 1D and 1.5D bends are fairly standard within the industry, these bend radii will not suit every need. Anyone considering pipe bending should take into account what kind of bend they need, be it 2D, 3D, or even 5D Bends.

What is 5D Bending?

What does it mean to get a 2D bend or a 5D bend? How are these bends different from the industry standard? The D represents the outside diameter of the pipe, measured in inches. The bend radius is then multiplied by the outside diameter to indicate the type of bend to be made. For instance, a 1.5D bend would feature a curve 1.5 times larger than the diameter of the pipe to be bent, so if you needed to bend a pipe 2 inches in diameter with a 1.5D bend, you would end up with a bend of 3 inches in radius. 5D Bends, then, are significantly larger than the standard, resulting in larger radius coils to serve a variety of purposes.

Why You Might Need 5D Bending

Larger radius bends allow the product flowing through the pipe, whether it be water, natural gas, or some other substance, to flow more smoothly. There is less resistance and a shorter travel distance for the product, which increases efficiency. In addition, a wider bend radius allows the pipe to reduce turbulence when compared to standard fittings. 5D bends offer lower costs for testing and producing pipe spools, and help to increase the efficiency of fabrication. Consider whether the traditional 1D or 1.5D bends can handle whatever job your pipes need to perform; if there is any doubt, consider using 5D bends for your next piping project.

What to Look For in Pipe Benders

When looking for pipe benders, especially when requesting a non-standard bend such as a 3D or 5D bend, it is of paramount importance to make sure the company you hire has plenty of experience and expertise. Try to choose a company who will do the work themselves rather than hiring a third-party contractor, as this will help ensure that your timeline will not be delayed due to unforeseen hold-ups on the part of the third party. Make sure whichever company you hire has high customer satisfaction and long years of experience in the industry.

5D bends have been used for years in oil refineries and on oil fields, in the petrochemical industries, and in countless other industries. This type of precision bending can be invaluable to any piping project using volatile substances, such as oil or gas, since this type of bend reduces turbulence within the pipes. Custom pipe bending is often the only way to get satisfactory 5D pipe bends in a timely manner. If your piping project requires a wider bend radius, or if you’re just looking to increase fabrication efficiency while reducing costs, consider 5D pipe bends.

Industrial piping systems seldom run straight. Pipe fabrication is a widely used method of forming metal piping into varying shapes that allow a pipe to round a corner or form a connection with a previously existing pipeline. Pipe bending, especially 3D bends, include shaping a section of pipe into a gentle curve, an angle, a coil or even an irregular shape with multiple curve radii. 

Pipe Fabrication Basics

Pipe fabricatio n includes many steps, one of which is pipe bending or forming. Pipe forming is carried out using one of several methods. Cold forming is performed with the metal at ambient air temperature, usually between 50° and 100° Fahrenheit. Hot forming involves heating the metal to temperatures above the point of crystallization. Hot forming requires less energy input to perform the actual bending, but the process of cold forming imparts additional strength to many types of metal. Sections of piping can be bent using rollers and dies in a procedure called pipe rolling. Bending can also be achieved using a single pressure point to bend the pipe around a die. Bending in this manner usually includes the use of a metal mandrel inserted inside the pipe to preserve the internal dimensions. Pipe rolling generally does not require the use of a mandrel. Other steps in pipe fabrication and 3D bends include welding, riveting and application of specialized coatings. 

Pipe Fabrication Configurations

A section of pipe can be bent into nearly any shape using pipe rolling and bending procedures. Some applications require only a gradual curvature of the pipe. One method of specifying pipe curvature is to bend the pipe into a curve with a radius that is a multiple of the diameter of the pipe’s cross section. For example, a pipe can be bent into a curve with a radius that is two times, three times or four times the external diameter of the piping. In other cases, conditions necessitate that a pipe must be bent to a specific angle, such as 90°, 120° or 180°. In yet other situations, an irregular shape might be required that must be formed using a series of curves of different radii. 

3D Bending Defined

Three-dimensional pipe bending is the method used to bend a pipe into an irregular shape. Three-dimensional bending is generally used to ensure that two different pipe sections can be joined properly or an immovable obstacle can be avoided by the pipeline. Forming a section of pipe into a spiral is another application of three-dimensional pipe bending. Three-dimensional bending can involve the use of several different sets of dies and rollers. While the process may involve more steps than bending a section of pipe within a single plane, bending a pipe into a three-dimensional shape is not inherently complicated. 

Practical Applications for Fabricated Piping Systems

The purpose of most pipe fabrication processes is to construct a pipeline that can carry a fluid from one point to another. Fabricated pipeline systems are used in heavy industry, pharmaceutical manufacture, food processing, chemical manufacturing and petroleum transport and refining. Pipelines carry a variety of fluids including petroleum, steam, water, industrial chemicals and food products. Pipe bending is also used for architectural design and structural applications. In these cases, the internal diameter of the pipe is not as important the strength and appearance of the finished product. 

Pipe forming and bending, including three-dimensional bending, are important steps in the pipe fabrication process. The bending of metal piping requires a significant energy input, but the finished result has many practical uses in a variety of industries.

Helical coils are used for a wide variety of applications across many different industries. They can be manufactured in a variety of gauges and different metals including steel, copper, stainless steel and titanium. The helical shape makes the coils a superior choice for applications that require high temperatures. In these cases, straight tubes pose mechanical problems because of thermal expansion. This weakness is minimized in coil tubes. They are more able to distribute heat evenly and, therefore, expand more predictably.

Made to Specification 

Helical coils come in three basic configurations the single coil, nested coil and tapered spiral coil. Most manufacturers can create custom coils based on customer specifications. These specifications can include material types and terminal end provisions such as threads or flanges. There are also many types of standard coils available to use as replacement parts.

Greater Surface Area

The coiled tubes have the advantage of providing greater surface area within a small volume or area. These gains in surface area make them a good choice for condensers and evaporators. They can be used for applications with small temperature differences or that have high volumetric heat rating. The coils have very high pressure ratings and are an excellent choice for high pressure applications.

Superior Heat Transfer Capabilities

Helical coils have superior heat transfer capabilities and are an efficient choice for compact heat exchangers. The single point connections found in helical coils greatly reduce the potential for leaks and simplify the installation process.

Combinations are Endless

Coils can be manufactured from virtually any metal or combination of metals. They can be manufactured in any size. They can be used in alkaline solutions, acid solutions and rinse tanks. This adaptability means that helical coils can be used in many applications across a wide variety of industries.

Nuclear Industry

Helical coil steam generators are used in the nuclear industry. The coils are often used in the aerospace industry because of their strength, heat resistance and compact design.

Household Appliances

Helical coils can be found in many household appliances such as refrigerators, boilers and air conditioners.

Chemical Industry

The chemical industry has many uses for helical coils. With the wide variety of coil materials available, they are very resistant to rust and corrosion due to chemical exposure. Their compact nature makes coils an excellent choice for electronic applications where space is always at a premium.

Food Processing

Food Processing plants make use of coils for food production. They can be found in large dairy processing plants and pet food production facilities.

Medicine

Helical coils are used in hospital equipment where precision is extremely important. Minute coils are even used in the human body for medical treatments. Pharmaceutical companies use helical coils in their manufacturing processes.

Helical coils can be found in nearly every industry or machine. Some other industries that use helical coils are biodiesel, asphalt and paving, automobile, plastics manufacturing, sanitation, laundry and mining.

The unique properties of helical coils make them an extremely useful component in nearly any machine. The helical shape gives the coils the ability to increase the surface area that can be used to exchange heat, speed evaporation and reduce the instance of leaks and spills. They can be manufactured in an endless variety of sizes, materials and configurations. It is easy to see why they can be found in so many different applications, machines and industries.

Davit arms come in many sizes and styles to facilitate the particular functions necessary for their designated roles. Because of this, customization is a key consideration when it comes to their design and production.

What Are Davit Arms?

Davit arms are apparatuses made of wood or steel and are sometimes jointed. They come either singularly or in pairs, depending on their need, and fit at the top of any drop-off where they serve primarily as cranes for a variety of purposes.

Historically, these devices served large vessels as a means of lowering dinghies and other small craft. In 1926, A.P. Schat set forth to improve davits systems by making them more dynamic and safer in operation. Davit makers have used his patented designs as a guide ever since.

The arms, specifically, come in at least three basic styles, although other combinational forms exist as well.

Lean-over – for extension over edges.
Vertical – with a spine for high-rise positioning.
Portable Cantilever – for maneuverability or transportation.

Features for davit arms are contingent on the particular purpose, but typically involve configuration capabilities, swinging and flexing adjustments, weight balance and space accommodation. Davit arms are just as much for enhancing appearance and facilitating human movement as they are for performing their primary tasks. For this reason, many industries have adopted their use.

What Do Certain Industries Use Them For?

Several industries implement davit arms, and for multiple uses. That shows just how versatile and sophisticated these devices have become.

Public Safety electric utility requires davit arms for conductor/fiber optic suspension. Utility vehicles feature davit units to conduct rescue or perform work in confined areas.

Construction davit arms serve primarily as a means of retrieval and elevation. They quite often perform these tasks simultaneously, as in the case where pallets or iron beams ascend, descend or shift from one area to another when delivering personnel and/or supplies where they need to go. This includes confined spaces where access is difficult.

Manufacturing davit arms work much like jib cranes that facilitate the production process. Assembly lines require davit arms to crane parts into position or lift away obstructions to make work easier.

Cruise Lines’ davit arms lift/drop cargo, anchors and lifeboats. These operate on hydraulic, free-fall and/or mechanical systems controlled by a limit switch.

Military/Naval davits hoist/lower lifeboats with the double-link Pivoted Gravity system. They use a drum-type winch that has a wire rope fall. Retrieval capabilities increase anchorage height and decrease mast extension when necessary.

Fishing davits, also called “firm davits,” function as cranes to lift the anchor flukes to the bow. Curved arms, made of timber or iron, extend over the stern sides to lift/lower lifeboats. These davits also raise fishing nets and other hauling necessities.

Oil/petrochemical oilrigs use davit arms suspend and move items such as oil drums for reorganization, cleaning and damage control purposes. These facilities also have lifeboats for emergency departure in case of fires.

Shipping davit arms elevate/suspend personnel, cargo and supplies, as well as offer support and balance for the purpose of organization, clean-up and damage control.

In the current age, davit arms are a necessity in virtually every aspect of life. The continuing expansion of their designs reflects the growing needs of human civilization, and shows how davit systems will influence the technology to come.

Steel and other metals can be shaped using a number of methods. Cold bending is one of the most frequently employed means of shaping steel into many different configurations.

Cold Bending Process

The process of cold bending steel is actually performed at what is considered room temperature. It is referred to as cold bending to differentiate the process from hot bending in which steel is heated by a torch or furnace before shaping. This process is generally performed using rollers to press a piece of steel against metal shaping tools called dies. It may also be referred to as cold rolling or pyramid rolling.

Benefits of Cold Bending

Cold bending does not require the use of fuel to heat the steel before processing, and the additional time and effort of heating and then cooling the steel are eliminated. Cold rolling results in a smoother, more finished surface and generally causes less deformation of the item being processed. One additional benefit is the increased strength imparted by working the steel while cold. When steel is manufactured at high heat and then allowed to cool it develops an internal crystalline arrangement. Working steel at ambient temperatures below the point of crystallization has been shown to enhance strength at a molecular level by compressing and distorting the crystalline structure. As the molecules become compacted they are unable to move as easily and, therefore, the steel becomes stronger. Working steel at high heat above the point of crystallization means that crystallization will occur after the steel has been worked and therefore the steel will not be any stronger than unworked steel. Heating steel that has already been cold bent or rolled will cause the material to lose the extra strengthening gained from the process by allowing the steel to regain its internal crystalline structure. The trade-off between cold and hot working processes is that in exchange for the added strength of cold working the steel can become more brittle, while heat worked steel generally retains greater ductility.

Cold Bending for Different Steel Configurations

Any cross-section and size of steel can be cold bent or rolled as long as it can fit into existing dies and rollers. Cold bending is most commonly applied to pipes of less than 10 inches diameter, channels, I-beams, angles and rectangular, round and half-round bars. Large scale steel products such as plates can also be worked but sizes are limited due to the force necessary and the size of the rolling equipment needed. The bending process can be used to create gentle, large-diameter curves, 90ｰ corners or long series of pipe coils in which the pipe bends in a succession of 360ｰ circular turns.

Uses for Steel Shaped by Cold Bending

Cold bent steel has many uses. Curved steel formed by cold bending is frequently used in the construction of buildings and bridges and is especially impressive when left exposed to view. Shipbuilders, railroads and automobile manufacturers also use cold bent steel products. The petrochemical industry uses curved and coiled piping for processing and transporting their products. Cold bent steel also has many other industrial and food-processing uses as well.

Cold bending is an excellent way to shape steel with minimal deformation during the bending process. Steel shaped by cold bending can be found in applications ranging from commonly used everyday items to highly technical specialized industrial applications.

Although it is an intensely hard material, steel is ductile and malleable and can be formed using various mechanical means into a wide variety of shapes. Bending stainless tube is a process that can be utilized to shape stainless tubing into many useful configurations.

Steel Bending Basics

Steel can be bent into a number of shapes but the process takes an enormous amount of direct pressure applied by specialized equipment. The difficulty of bending a section of tubing depends upon the thickness of the tubing. While thick-walled tubing requires more force to bend, it is less likely to fail during the bending process than thinner walled material. Different sizes and shapes of pipe each require their own sets of bending tools. Companies that specialize in bending stainless tubes must maintain dozens or even hundreds of sets of bending implements in order to bend different tubing configurations.

Methods of Bending Stainless Steel Tubing

Stainless steel tubing may be shaped into gentle curves by rolling. This process uses rollers to force a section of tubing over or around a die, a specially formed tool designed to change the shape of a piece of metal. When making a sharp bend in stainless steel tubing a metal piece called a mandrel is inserted inside to prevent the tube from losing its shape during bending. The tubing is then placed near a die and mechanical pressure is applied to the tubing which forces it to bend around the die. There are limitations to the degree of curvature that can be achieved with any pipe shaping process but bending generally produces much sharper curves than rolling.

Bending Seamed Stainless Steel Tubing

While any kind of steel tubing can be shaped by bending, tubing that is formed without seams generally responds better to the bending process than welded or seamed tubing. Even moderate bending can weaken or rupture a seam although this problem can be diminished somewhat by bending the tubing in a manner that lessens the stresses placed directly on the seam.

Other Structural Considerations for Bending Stainless Steel Tubing

In addition to weakening a seam, the process of bending can weaken the structure of the tubing itself. When a tube is bent the steel along the outside of the curve is stretched while the material on the inside of the curve is compressed. If the tubing is bent too sharply the exterior of the curve may become significantly thinner than the rest of the tubing, making that area more prone to failure.

Another important consideration with stainless steel tubing is the preservation of the pipe’s internal diameter and structure. Even when a mandrel is used the tubing may deform slightly during bending. Any deformation in the internal diameter of a tube or pipe that carries a liquid can disrupt the flow pattern of the fluid inside. This in turn can lead to scouring of the inside of the tube which could lead to thinning and eventual failure. When tubing is bent for structural or decorative purposes deformation of the internal dimension of the pipe is less important.

Uses of Stainless Steel Tubing

Products made by bending stainless steel have many uses. Stainless steel is an inert form of steel that is ideal for use in food processing, food service, and pharmaceutical manufacturing operations. Stainless steel tubing also has structural uses and can also be polished for decorative purposes including railings, light fixtures, and artistic pieces.

Stainless steel tubing requires special handling and tools to bend properly. When bending is performed properly, however, the finished product has many important industrial, structural, or even ornamental uses.

The Thermal Fluid Heater
These Serpentine Coils systems move some form of a liquid through pipes. It works by moving the recirculating liquid through cylindrical coils. Passing through a heat exchanger, the liquid is heated, and that heat can then be used further down the line for other purposes. Additionally, there are some systems available that pass the liquid through the exchanger multiple times to achieve higher temperatures.

Typical Uses
When something needs to be heated to between 200 and 750 degrees Fahrenheit, these are an excellent choice. They are used for heating press platens such as the ones required to make OSB and plywood or other laminated materials. They heat calendar and drying rolls for various purposes, and they can heat a variety of chemicals and even equipment like reactors, dryers, evaporators and heat exchangers.

Low Pressure is Better
Unlike other heating systems, these work with very low pressure. The only pressure required is the level needed to move liquid through the lines, so they are safe to work with. Correctly designed and installed, they are also very efficient and will reliably produce the high heat levels required. There is little wear and tear on the system with low pressure, so maintenance costs are lower.

Serpentine Coils are Ideal
The radiant coil is an integral part of these systems, and the best coils feature a serpentine design. There are a few key benefits to this design. With a serpentine pattern that allows liquid to heat steadily as it moves around the heat source, higher temperatures can be developed in the liquid. The flow is smooth and steady, so the thermal fluid will not bog down or stop moving at any point. The steady rate of flow provides efficient heating and functioning, and the coil will also last longer because the flames do not directly touch the coils, but heat steadily circulates around them.

Choosing a Thermal Fluid Heater
Maintenance is an important part of any system. The rounded serpentine coil is ideal for minimizing the direct heat source while still warming the liquid inside the coils, and it’s also easier to maintain. Look for a system where the coil can be removed for cleaning and any necessary preventive maintenance like replacing gaskets or repairing tubes. With this type of design, any maintenance that is necessary will also be completed faster, and that limits downtime and repair expenses.

There are different efficiency ratings for various heaters. The thermal fluid heaters with a serpentine coil achieve energy efficiency levels of 90 percent L.H.V. to help businesses control rising operating costs.

Businesses that need to move heat through machinery will appreciate the benefits of thermal fluid heating. Efficient, safe and durable, these systems make working teams safer and help them do their jobs better. The best systems for almost any application use serpentine coils to move the liquid through the heat chamber more efficiently. These heaters are also more affordable to maintain and offer higher energy efficiency ratings.

Pipe Rolling Process

The process of pipe bending entails the application of pressure at a single point to make a single bend in a pipe. If a second bend is required the pipe is repositioned for the second bending procedure. Rolled pipe differs from bending in that pipe rolling uses multiple rollers that apply pressure to a moving pipe to achieve a continuous curve. Enormous pressure must be applied to create the curves and bends in rolled metal piping. The degree of curvature is determined by the use of one or more dies upon which the pipe is pressed by the rollers. A die is a specially formed piece of metal that is used to shape other metal objects. A large diameter die produces a more gentle curve while a smaller die makes a tighter curve. Pipe rolling is usually performed on “cold” piping, which means that the pipe is the temperature of the ambient air and is not heated as part of the rolling process.

Pros and Cons of Rolled Pipe

Rolled pipe cannot be bent into tight corners as can be achieved with standard pipe bending procedures. However, utilizing pipe rolling instead of bending allows a pipe to be formed into the necessary shape with little or no compaction of the interior diameter of the pipe. This means that the flow of material inside the pipe is not impeded and the flow pattern is not disrupted. While rolled pipe cannot be bent as sharply as standard single point pipe bending, a much greater variety of shapes can be achieved through rolling. Despite all the benefits, pipe rolling is a more complex process than pipe bending because the pipe is moving while the pressure is applied. The rate of motion may require variation throughout the process or remain constant. In some cases the dies used must also be changed at various stages to achieve the desired result.

Rolled Pipe Configurations
Pipes of differing cross sections including circular, elliptical, square or rectangular can be shaped by rolling with very little change to the structure of the pipe. The diversity of shapes and configurations that can be achieved using pipe rolling are almost limitless. Pipes can be bent into the most gradual of single curves or into S-curves, spirals, 90-degree bends and coils.

Uses of Rolled Pipe
Many manufacturing and heavy industry processes require the use of curved piping. Petroleum, natural gas, water, steam and industrial chemicals are all transported through pipeline systems. Heating, ventilation and air conditioning (HVAC) systems also require curved piping and pipe coils that can be produced by pipe rolling. Rolled piping is also used as reinforcement in automotive and construction applications.

Despite the drawback of requiring additional processing steps, pipe rolling is a widely-used and versatile method of shaping pipe. The unlimited configuration possibilities of rolled piping mean that this technology can be used to make a pipe to fit nearly any purpose.

Less Resistance

Reduced Travel Distance

Larger Radius

Lower Cost