Advancements in orbital welding electronics
May 5, 2010
The orbital welding process has seen significant advancements in electronic control technology that have helped open the door to a wider array of applications while making it more cost effective to use.
Have you ever wondered how orbital welding technology evolved or just how long it has been around? Believe it or not, orbital welding is 50 years old. During its lifetime the process’s electronic control technology has advanced significantly, which has helped streamline the process while making it more cost-effective to use.
Very little information exists beyond the “tall tale” of who exactly did what first. However, it seems to be generally accepted that as North American Rockwell, Canoga Park, Calif. (later renamed Rocketdyne), worked on the X-15 rocket plane project in the late 1950s, it realized it needed a high-quality and repeatable method to weld small hydraulic tubing. In 1958 an engineer named Roderick Rohrberg designed and built the first orbital tube welding system while employed at North American Aviation. In those early days, orbital welding was a well-kept secret. Rocketdyne was interested in the process for its own use, and so the technology remained in-house. After Rohrberg left North American Aviation he opened up his own orbital welding manufacturing company in the late 1960s. Rocketdyne further developed the orbital welding process through the early 1960s as part of its Apollo command module project. In 1964 Rocketdyne applied for some of the first orbital welding patents.
Early orbital welding electronic technology relied heavily on a relay/timer-based welding controller that, according to today’s electronic standards, is fairly primitive. However, if you were to compare weld quality achieved with early technology with weld quality from current technology, you would be hard-pressed to tell the difference. It is important to note that in the technological evolution of the orbital welding system, today’s basic autogenous orbiting GTAW process is almost identical to the early process. What has changed, however, has been the control aspect of this mechanized process. Over time the rapid development of the electronics industry had a dramatic effect on orbital welding.
In the 1970s most orbital welding equipment used relay/timer technology. At that time the cost of a typical orbital welding system was still prohibitive, so the customer base was limited to aerospace and other highly technical industries. Relay/timer technology remained the standard for more than 15 years. In fact, many of the older orbital welding specialty companies still use this technology.
The microprocessor did not appear on the orbital welding scene until the late 1980s, even though the technology was developed a decade before. Typically, orbital welding electronics is about 10 years behind integration of new electronic technology. This is mostly due to the reduction in cost after the newness of the electronic technology has worn off. When the microprocessor was introduced, it allowed the operator to execute the weld from a computer program, collect data, store programs, and control overrides. It also lowered cost significantly.
For the next 20 years microprocessor-based orbital welding systems were the standard. These systems are considered as partially digital, because the system itself still functions on analog signals. Thousands of these systems are used in the aerospace, semiconductor, pharmaceutical, food processing, dairy, and beverage industries, or anywhere that requires high-quality stainless steel welded tube.
At the turn of the new millennium, a new generation of orbital welding electronics began to make its way onto the market with 100 percent digital control. Some of the advantages of the fully digital system are:
If you think about the more recent advances in electronics, it seems obvious that analog technology has become outdated. If you don’t believe it, just try to go out and purchase an analog cellular phone.
Another feature of fully digital control systems is their ability to autoprogram. In most cases, the programmer needs only enter a tube size, wall thickness, material, and the weld head. From there the system self-calculates a basic program and is ready to weld. The operator then has the freedom to adjust individual parameters and fine-tune the weld as needed.
Just like with the microprocessor, digital technology has reduced the cost of a typical system while increasing its capability; over the past 30 years, a typical orbital welding system has come down in price from about $80,000 in 1980 to $25,000 in 2010. This is due largely to electronics technology advancements.
So what does the future hold for orbital welding? With the current status of electronic technology, we can only conclude that the orbital welding systems of the future will have more capabilities and flexibility to interface with other electronic devices. Additionally, the technology will again drive down the cost, making orbital welding a more affordable and common process. The speed, precision, and repeatability of these digital controls are the key factors that will transform tube and pipe welding in much the same way CNC technology transformed machining.