Optimizing your welding process with ventilation, tables

WWW.THEFABRICATOR.COM MARCH 2016

MARCH 14, 2016 BY: BENJAMIN HOWELL

Is there room for improvement in your welding operation? Choosing the right ventilation system along with flexible worktables can go a long way toward optimizing your welding process

Figure 1 - CleanAir Tower
Figure 1 – CleanAir Tower

The best way to optimize any welding process is to use up-to-date, well-designed equipment in a safe, properly ventilated environment. Not only does this enable you to work accurately and cleanly, but it also helps you speed up the production process and ultimately reap cost benefits as well.

Of course, the tools and equipment you choose must meet the requirements of the welding job to be done. The ventilation system you select is determined, to some extent, by the location in which you are working.

When working in a welding workshop or industrial warehouse, the best option is to use a system that delivers full-room ventilation. In addition, modular welding tables that can be adjusted are ideal for most workshop environments, particularly those that accommodate a full range of welding tasks.

Welding Workshop Ventilation

Health and safety are vital issues for welders who, by the very nature of their jobs, face daily health risks from exposure to fumes, smoke, and welding dust. Protective safety gear and clothing are essential, but it isn’t enough. Effective ventilation is paramount, because bad ventilation contributes to polluted air, employee illness, and decreased productivity.

The Occupational Safety & Health Administration (OSHA) has minimum health and safety regulations that relate specifically to ventilation and protection in welding, cutting, and heating. Mechanical ventilation must meet these requirements.

Specifically, the regulations state that mechanical ventilation must consist either of a local exhaust system or a general mechanical ventilation system. The standard states that:

  • General mechanical ventilation should have sufficient capacity and be arranged so that it can produce the necessary air changes to ensure that welding fumes and smoke are maintained within safe limits.
  • Local exhaust ventilation should incorporate hoods that are freely movable so that the welder can place it very close to the workpiece to get rid of fumes and smoke at the source.

But both have their challenges.

For example, even when exhaust systems are in place, pollution concentration levels can exceed OSHA’s exposure limits, exposing all employees in the building to poor air quality. Welding creates smoke, fumes, and heat. Warm, polluted air rises to the ceiling; as it cools and then sinks, it distributes contaminants, negatively affecting workers on the production floor.

When the traditional push-pull ventilation system is used, the inevitable air turbulence it causes (however slight) results in some pollutants getting into what should be clean air. This type of system relies on pipes that push clean air into the workshop and pull the contaminated air out. Essentially a duct system, it works reasonably well where dust and smoke levels are quite low, but it certainly isn’t foolproof.

Additionally, this is a minimum OSHA specification. Ideally, a local exhaust system should be used in conjunction with a good, general mechanical system for maximum protection. In any case, when local extraction doesn’t work adequately, or at all, good general mechanical ventilation is the answer.

Figure 2 - Partially covered welding table
Figure 2 – Partially covered welding table

Full-room Ventilation

The best system for ensuring that the air in the welding workshop really is clean and pure is a device that works according to the principles of displacement ventilation, such as a freestanding air tower (Figure 1) that takes advantage of the natural convection cycle.
These energy-saving, general indoor ventilation systems are designed to release fresh air throughout an entire production facility. Quick to set up, easy to move, and self-cleaning, they use source-capture fume-extraction technology that is fully OSHA-compliant.

A clean-air tower works by pulling warm, contaminated air into its filter system through a 360-degree intake at the top of the tower. It then releases cool, clean air from the bottom of the tower to ensure welders are able to breathe fresh air all the time. The polluted air is filtered through an internal filter cartridge, and dust particles are captured in a container for easy removal and contamination-free disposal.
Thermic flow is fully supported without creating any air turbulence, so it’s virtually impossible for dust and gases to pollute the purified air.

Adjustable Welding Tables

You have many choices when it comes to welding tables, including those that are partially covered, movable, have steel support surfaces, and can incorporate their own tool racks. But for anyone working with mild steel and stainless steel, a 3-D welding table with a T-slot system is ideal (Figure 2). Modular, these adjustable designs are able to hold accessories and 3-D components for most welding tasks.

A quality 3-D welding table with a T-slot system allows the welder to access all sides of the workpiece, which increases overall efficiency and improves productivity. The size of the table can be changed, and the slats opened and adjusted to accommodate accessories required for the job. Additionally, the table slats can be adjusted at any time during the welding process.

To further speed up the process and make it even more cost-effective, an adjustable 3-D welding table can be used with a 3-D clamping system, which eliminates the need for the welder to move or change position to access the workpiece.

With the right ventilation and fixtures, you can optimize your welding process and work quickly and cost-efficiently.

Using Forster’s 3D Welding Table to Simplify Welding Jobs

Welding tables are a must have component for any serious welder’s workspace. Standard tables are usually made of steel since other types of material could not stand up to the intense heat needed for welding. This makes them durable but not very versatile. A typical welding table will be setup for a specific project and until that project is finished, the table cannot be used for anything else. 3D welding tables provide a versatile workspace for more complex projects and larger product output requirements.

Standard welding tables don’t give you any option to make changes or position adjustments midway through a job.

Forster 3D Welding TableFor this reason, a small shop or individual welder can get by using a single table but larger manufacturers need a lot more to meet demand. Since a standard table is not able to adapt to jobs of different sizes, a manufacturer is forced to dedicate one table to one project or one step in an assembly line. This is why more and more large manufacturers are switching over to a Forster 3-D Welding Table.

3D Welding Tables Simplify Larger Welding Projects and Increase Output

A Forster 3-D Welding Table is extremely versatile and can accommodate projects of all shapes and sizes because of its “T-Slot” system. The T-Slot system utilizes slats that will open and adjust to accommodate different projects and useful accessories. You do not have to wait until before or after a project to set up these tables as they can be adjusted on the fly.

Our 3D Welding Tables are available with:

  • Al/Cu alloy construction which allows for stainless steel processing
  • Grey cast construction for steel processing
  • The flexible T-Slot system which allows for an amazing array of configurations

If your company handles welding projects on a daily basis then you need to contact Forster America today. There is no point to filling your welding bays with limited tables that can only handle one type of project when you can fill your workspace with Forster 3-D Welding Tables. They can do anything a standard table can do and so much more.

Forster’s Hydraulic Turn-Tilt Welding Tables are Precise, Safe and Ergonomic

Professional welders who want to ensure they adhere to optimum welding parameters, and produce top quality work that requires minimal surface finishing, will appreciate the benefits of Forster’s amazing hydraulic turn-tilt welding tables.

Not only do these high tech tools enable fast, accurate downward seam welding, they are also safe and ergonomic, making the job easier, quicker and more comfortable for those welding.

Ultimately, they make old-fashioned, flat-topped welding workbenches seem totally archaic.

The Turn-Tilt Design

Forster Turn Tilt Table for Stainless SteelForster’s hydraulic turn-tilt welding tables are designed for infinite three-axis adjustment of work pieces. As the name suggests, they can be easily turned and tilted, and their height can be controlled so that a perfect ergonomic position is achieved for welding. This enables welders to work fast and precisely and increases productivity, and therefore profitability as well.

Hydraulics ensures that both the height and tilt adjustments can be securely positioned at exactly the right point. A WS-drive coupled with inverter control ensures that the turning movement is precise and smooth in all loading conditions.

Integrated safety valves are incorporated into the design of these welding tables to prevent unnecessary damage to the hydraulic hoses that serve to turn and tilt them. Catering to the ultimate needs of professional welders, a hand-held pendant allows users to control all table movements manually, and to monitor the way the table operates using a digital speed indicator.

Forster’s turn-tilt welding tables feature optional foot pedals for both starting and stopping rotation, and for speed control. Additionally, there are options that allow for external rotation control as well as wireless remote control. Turn-tilt tables can also be fitted with a neatly slatted top.

Technical Information About Forster’s Turn-Tilt Tables

Rotary tilting tables are available in five sizes that vary in both weight and proportions. The smallest weighs just 520 kg and is 820 mm wide and 1,930 mm long. The diameter of the tabletop is 650 mm and the height varies from 680 mm to 1,370 mm. This size turn-tilt table can withstand a load of 8,000 N and weight of 800 kg.

The largest available Forster turn-tilt table weighs 8,000 kg and can withstand loads of up to 160,000 N and a weight of 16,000 kg. These feature a large tabletop with a diameter of 1,600 mm and are 2,540 mm wide and 4,000 mm long. The height range varies from 1,100 mm to 2,450 mm.

Comparing other technical features, the smallest table has a torque of 800 Nm while the largest offers 16,000 Nm. Spin-up is from 0.07 to 1.6 rpm compared to 0.03 to 0.7 rpm. Breakdown torque of the smallest is 1,700 Nm compared to 80,000 Nm for the largest design.

Other sizes cater for weights of 2,500 kg, 4,000 kg, and 8,000 kg and loads of 25,000 N, 40,000 N and 80,000 N. Proportional sizes of these are 1,200 mm x 2,400 (with a height of 650 mm to 1,640 mm); 1,430 mm x 2,770 mm (730 mm to 1,760 mm high); and 1,880 mm x 3,100 mm (805 mm to 2,130 mm high).

So whatever your needs, there is a hydraulic turn-tilt table from Forster that will suit you.

Forster America’s Welding Work Piece Manipulators Make It Easy to Finish Large or Complicated Projects

Welders working on large or complicated projects can improve quality, safety, and work ergonomics, and become substantially more efficient and productive if they use well-designed work piece manipulators.

Forster welding manipulator systems incorporate tilting tables that turn and lift, as well as 3-axis positioners, and additional robot axis devices that improve a welder’s ability to produce the very best items possible. Essentially these hi-tech tools enable welders to work at a height that is ergonomically proven and also reach all the weld seams in flat positions.

Welding work piece manipulators are invaluable because they may be used for manual welding and in conjunction with welding robots. They may also be customized. The chief value of manipulators and positioners is that they make the work piece more accessible, and in this way enable welders to speed up the welding process.

Turn-Tilt Tables

Turn Tilt Table with Top
Turn Tilt Table with Top

Turn-tilt tables are relatively small and compact, and ergonomically designed for adjustment of infinite three-axis work pieces. The beauty of them is that they can be turned and tilted, and the height adjusted, to ensure secure, accurate positioning for optimum working and welding positions. They are ideal for achieving optimum welding parameters and ensuring better quality with less surface finishing required. They are also precise, and particularly useful for fast downward seam welding.

All movements of turn-tilt tables are controlled, very easily, by hand and enable operators to monitor the way the table operates with a digital speed indicator. There is also an optional foot pedal for start-up, speed control, and for stopping. A wireless remote control is also available.

The tables are also safe, and they feature integrated safety valves that prevent hydraulic hoses being damaged.

Available in five different sizes, and from weights of 520 kg to 8,000 kg, Forster turn-tilt tables are suitable for loads from 8,000 N to 160,000 N (Newton’s unit of force.) They can carry work piece weights of between 800 kg and 16,000 kg,

Axis Positioners

Forster 3-Axis PositionerForster’s three-axis positioners have a lifting function and two rotary axes. Like Forster’s turn-tilt tables, they are designed so they can be positioned for an ergonomic working height when welding. They are suitable for both manual and robotic welding and ideal for reaching welding seams easily and accurately when working in a flat position.

Axis positioners can be used to lift the work piece up 1,100 mm. They can rotate 185 degrees on the horizontal axis and a full 360 degrees on the vertical axis. A position-limiting switch provides collision protection.

Forster America designs and manufactures positioners to meet very specific client needs, including handling large objects.

Additional Robot Axis Manipulators

Forster Additional Robot AxesThe additional robot axes are even better for welding seams using either manual or robotic methods of welding. They have a similar lifting functionality as the axis positioners (1,100 mm) as well as a two-axis rotation that will enable workers to reach all the weld seams. Both horizontal and vertical axis rotation is the same (185 and 360 degrees) and the same collision protection is available.

Additional robot axes are commonly used for the production automation of high-volume components. A substantial amount of time is saved because they can be used as a moving work piece.

Without a doubt, Forster America can help any competitive welding business manipulate its work in the best possible way!

 

 

From The Fabricator: Customizable Welding Tables Simplify Operations and Enhance Productivity by Michelle Howell

Professional welding jobs can be complicated, particularly when complex designs call for absolute accuracy. For this reason it is essential to ensure that the equipment used is right for the job at hand, not only in terms of specialized welding machines, but also in terms of the welding table chosen.
Welding Table Efficiency
Generally, the most efficient and cost-effective practice for a professional workshop is to invest in customizable welding tables that are appropriate for the jobs done most often, rather than have multiple welding stations for different sizes and types of metal. Carefully selected modular welding tables can be used for both simple and complex jobs regardless of frame, rail, and custom requirements.

Click here to see the full article on The Fabricator

The Top Tips for Welding Copper

Copper is a soft, non-ferrous metal that can be easily bent, cut, shaped and joined using several welding processes. While it is often used to make decorative household and architectural items, it is an excellent conductor of electricity and heat, and so is widely used in the electrical industry, while copper pipe, valves and other fittings are commonly used for plumbing.

Since it is ductile and highly malleable, copper is also used as the major element in hundreds of different alloys, including brass, bronze, and nickel copper. The most common alloying elements used for copper alloys are aluminum, nickel, zinc, tin, and silicon.

Because pure copper is too ductile to be successfully machined, small quantities of other elements are added to the various alloys to improve machinability, as well as to deoxidize the metal, make it more resistant to corrosion, improve its mechanical properties, and improve its response to heat treatments. In all there are more than 300 copper alloys available commercially.

Joining Copper to Copper or to Copper Alloys

welding-copperCopper and most copper alloys can be successfully joined using welding, brazing or soldering processes. The exact process chosen depends largely on whether you are welding pure copper or an alloy. If you are welding an alloy, the alloy elements will determine which process is used, as well as all the other factors one takes into account when welding, including filler material used.
Of course, the different welding and related processes require different tools and techniques, and it’s important to learn the skills required for which process you need to use.

Soldering, which is one of the earliest methods used to join metal, involves heating filler metal (in the form of a filler wire) so that it melts and fills joints. Soft soldering is the simplest process, and the one commonly used in and around the home to repair small metal items. It is also the method used by plumbers to join and repair copper pipe and copper fittings.
You can use an inexpensive soldering iron or a blowtorch with a suitable flux for soft soldering. Hard soldering involves heating the filler materials to a much higher temperature, so the joint will be a lot stronger than other soldered joints. The filler material is different and usually contains silver, so the technique is often referred to as silver brazing. However, true brazing is executed at an even higher temperature.

Brazing is essentially a technique similar to soldering, and it utilizes the same sort of filler material (wire or a brazing rod) used for soldering. Joints need to be very closefitting so that capillary action can draw the filler metal between the pieces of copper being joined. Even though temperatures used must be considerably higher than those required for soldering, the base metal mustn’t be heated to melting point.
Used extensively for plumbing work, brazing may also be used to join different types of metal as well as metal work pieces that are different thicknesses.

Welding, or more accurately arc welding, incorporates a number of different more specific techniques. Generally, the welding processes that utilize shielding gases are preferred, though shielded metal arc welding (SMAW) which is also commonly referred to as manual metal arc (MMA) welding can be used for applications that are not critical. It is a useful method for a variety of copper alloy thicknesses, especially since covered electrodes for welding copper alloys using SMAW are available in a wide range of standard sizes.

The shielding gases normally used for welding copper and copper alloys are argon and helium, or mixtures of the two – for either gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), or plasma arc welding (PAW) which is particularly popular for welding copper alloys.
Generally argon is preferred if the copper or copper alloy is welded manually and either has a relatively low thermal conductivity, or is less than 3.3 mm (0.13 in) thick. Helium or a helium (75 percent) argon mix is preferred for machine welding thin sections, or manual welding of thicker sections. This mixture is also recommended for thicker metal or copper that has a high thermal conductivity.

Other top tips for arc welding copper include:
• Whenever possible use the flat position for arc welding copper.
• GTAW and SMAW can be used for welding in other positions, including overhead.
• If welding in vertical and overhead positions using pulsed power and small-diameter electrodes, GMAW may be used with some copper alloys.
• Thermal expansion of copper and its alloys, as well as its higher thermal conductivity, do result in greater weld distortions than when welding mild steel.
• To minimize distortion and warping, welders need to focus on correct preheat processes and tack welds, as well as following proper welding sequences.

Properties of Copper and its Alloys to be Aware of When Welding

Whichever welding process is used to join copper and its alloys, it is important to give attention to the properties that make the welding of copper different to the welding of carbon steels. For example, copper and copper alloys, when molten, are very fluid, and they have:
• High thermal conductivity
• High electrical conductivity
• A high thermal expansion coefficient that is about 50 percent higher than carbon steel
• A relatively low melting point
• Hot short that results in some alloys becoming brittle at high temperatures
• Strength that is largely due to cold working

The melting point of copper and its alloys is hugely variable, but it is at least 1,000 °F or 538 °C lower than the melting point of carbon steel. Also, copper doesn’t exhibit the same sort of heat colors seen when steel is welded, and when it melts its fluidity is much greater.

The Copper Development Association (CDA) Inc. that has established an alloy designation system widely used throughout North America, has a huge amount of information about welding copper and copper alloys for anyone wishing to learn more.

The Evolution of Welding [Infographic]

Welding is a fundamental part of almost every industry and product in today’s world. Some of the first welding processes we’re being utilized before iron was even discovered as a useful material, today there are many different popular welding processes for all types of metals and fabricaton.

Our timeline below begins in the “Bronze Ages” and shows all of the fundamental innovations in welding up until 1959, though there are many new technologies and processes being developed even today! Check out our infographic below to learn more.

The Evolution of Welding

Evolution of Welding Infographic | Forster America

Click the Infographic to see the Full-size Version!

 

 

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The American Welding Society Updates the D1.1 Structural Welding Code

The American Welding Society (AWS) has released its new version of the structural welding code for steel. Titled Structural Welding Code – Steel. AWS D1.1/D1.1m:2015, it supersedes the previous edition published in 2010.

AWS Logo | Forster AmericaThe revision represents a collaboration between the AWS D1 committee on structural welding and its sub-committee on steel, and it details all requirements for steel structures made from tube and plate. These include design and procedural requirements as well as those that relate to qualification as well as inspection and the repair of any structures manufactured using steel. It also covers structural steel shapes that will be subject to cyclic or static loading.

Apart from substantial changes to the text, additional commentary has been added to improve clarity in general, and to make provisions of the code easier for welders to understand.

Available from the AWS online store, the 646-page code costs $411 for members and $548 for those who are not members, and is available immediately as a PDF. Printed hardcopy versions will be ready for shipment from the end of September 2015.

The AWS lists the changes that have been made to D1.1 structural welding code in some detail.

General Changes

Parts of the revised structural welding code have been reorganized. For instance all tubular provisions, together with tables and figures, have been moved to a new section, Tubular Structures. A new section of commentary is also added here.

The AWS A5.36 code, Steel Flux Cored Electrodes for Flux Cored Arc Welding and Metal Cored Electrodes for Gas Metal Arc Welding has been incorporated as part of the structural welding code.

The section covering postweld heat treatment (PWHT), that is often used after welding to improve the weld, now has two additions: the American Society for Testing and Materials (ASTM) A709 Grade HPS (for high-performance steel) 100W [HPS 690W]. ASTM A709 100 (690) and 100W (690W) have been deleted.

Changes That Relate to Design

There are three major changes to the section relating to design:

  1. Calculation of the throat of a combination fillet weld and partial joint preparation (PJP) flare bevel groove weld has been clarified.
  2. Additional provisions have been incorporated for wrapping welds on opposite sides of a common plane so that seal welding may be permitted.
  3. Figures of fatigue curve cases have been revised so that they are in line with the American Institute of Steel Construction’s AISC 360.

Changes That Relate to Prequalification and Qualification

Conditions for backing metals other than steel in prequalified welding procedure specifications (WPSs) have been clarified. Requirements for “sub-sized specimens” in Charpy V-notch (CVN) tests have also been clarified.

Tables for prequalified filler metals and base metals have been updated and reorganized, and ultimately aligned with the table for prequalified preheat and interpass temperature.

There are also new figures for prequalified fillet weld joint details and complete joint penetration (CJP) groove, T-, and corner joints.

Fabrication Changes

A number of issues have been clarified in the section on fabrication, including baking requirements for the low-hydrogen electrodes that are used for ASTM A514 and A517 steels.

Preheat and interpass temperature requirements for welding with a combination of base metals have also been clarified, as have the provisions for oxygen gouging. Weld profile requirements have been clarified, and so have locations of the depth of the web from tension flanges of beams or girders. These are considered outside the tension zone for construction aid welds and for tack welds.

The requirements for backing and for cleanliness of substrates have been updated too. And revisions have been made to the location and sequence of members and element splices.

Inspection Changes

Several changes have been made in the section on inspection and there is a new table for the qualification and calibrations requirements of ultrasonic testing (U/T) equipment. Issues regarding retesting based on the quality of welding work have been clarified, and so have issues that relate to calibration for the sensitivity and horizontal sweep of U/T equipment.

Additionally, new figures have been added to the code to show more simply and clearly how to achieve effective throat for a variety of types of joint and joint combinations. Definitions and terms used in the code are now normative, and the sample welding forms provided have been revised extensively.

Lastly, the section on safe practices has been deleted and, instead, Clause 1 now includes safety references.

You can purchase the new structural code here at the AWS book store.

 

From The Fabricator: A Welding Ventilation Overview

By Benjamin Howell of Kemper America

a-welding-ventilation-overview-0Welding emission reduction is something that interests all metal fabricators, and today’s welding technology does a good job of removing welding smoke that can contribute to health risks. This can be misleading, however.

At the nanolevel, invisible to the human eye, the concentration of particulate matter can pose a great risk to welders. Studies show that welding fume particles are mostly smaller than 0.1 micrometer, which makes nearly all welding fume particles respirable. They can penetrate deep into the alveolate region of the lungs during inhalation and remain firmly fixed there.

Welders exposed to welding fumes on an ongoing basis run a significant risk of health-related problems. The most common symptoms include fatigue, breathing difficulties, shortness of breath, bronchial diseases, manganese poisonings, lead and cadmium oxides, episodes of metalworkers’ fever when welding galvanized materials, and even damage to the central nervous system. The harmful particulate matter generated during welding of nickel, chromium, and cadmium compounds can be considered carcinogenic.

Additional health risks are associated with filler materials. Ninety-five percent of harmful substances that make up welding particulate originate from the filler metal, and only the remaining 5 percent comes from the parent metal.

What safety measures should be employed to protect metal processing workers from such risks?

Click here to see the full article on The Fabricator