An interview with Fred Schweighardt: National Projects Leader for Airgas
Stainless Steel World Americas was happy to speak with Fred Schweighardt, an International Expert in welding and cutting, about his new role as National Projects Leader for Airgas, an Air Liquide company, and his almost 20 years of experience serving the industrial gas industry as a welding expert. By the Editorial Team
Airgas is the leading supplier of gases, welding equipment, and safety products in the U.S.A., Headquartered in Radnor, Pennsylvania, the Airgas network is comprised of more than 900 retail locations, cylinder fill plants, gas production facilities, specialty gas laboratories, and regional distribution centers.
Employing approximately 18,000 people across the nation and serving more than one million customers, Airgas supplies industrial, medical, and specialty gases, carbon dioxide, nitrous oxide, welding equipment, and supplies, process chemicals and more to industries including: manufacturing and metal fabrication, construction, chemicals, life sciences and healthcare, food and beverage, materials and power, defense, and aerospace. “The industrial gas industry is very diverse,” says Schweighardt. “Your cellphone, the metal parts of your chair, the fizz in your soda...none of it would exist without industrial gas. We have an entire medical group that does nothing but medical gas. We have a food segment and they focus on ways that you use industrial gas in food. I focus on the ways you use industrial gas in welding.”
Hoses for cryogenic and high-pressure applications
As a welding expert, Schweighardt works with high-pressure and cryogenic hose applications. At temperatures as low as -320°F, metallic hoses are the standard, as few other materials can withstand this temperature without failing. “For cryogenic hoses there are a relatively small number of materials that are suitable for low or high-pressure and low temperature at the same time,” explains Schweighardt. “On top of that, the hoses still have to be flexible.”
In these applications, Schweighardtuses a hose with a stainless corrugated inner tube and a braided and/or armored stainless outer, which protects the inner tube during cryogenic transfer. If he is particularly concerned about the flow characteristics, Schweighardt will use a hose with a Teflon-lined inner tube to prevent any liquids from getting into the corrugated ridges of the metal.
“It has to be stainless,” he adds. “Stainless is the only material that is financially feasible and has all the requisite mechanical characteristics that allow it to be flexible in low temperatures or under moderate pressure — up to 1,500 pounds per square-inch (psi). What we're looking for is ductility and low-temperature resistance. Austenitic stainless steels have a special microstructure that causes the metal to retain its ductility at a low temperature.”
Respect the bend radius for best results
As with all hoses, the single biggest threat to the health and longevity of a hose, whether it is a common garden hose or a USD$2,000 cryogenic hose, is not respecting the bend radius. “Over-bending is the number one thing that will bring a hose back for warranty or repair,” explains Schweighardt. “Any reputable hose supplier will tell you what the bend radius of a hose is. Say a hose has a bend radius of 30 inches — if you try to wrap that hose around a barrel that is 2 feet in diameter, a 12-inch bend radius, it is going to cause problems.”
Naturally, the damage is going to be worse at the coupling end of the hose, where the hose becomes rigid — especially when it is fastened with a coupling that is itself rigid. Schweighardt uses the example of a garden hose, “If you screw a garden hose onto your house, and then walk around the corner and start pulling, the first place that your hose kinks and bends and squeezes flat is right by the faucet. It is that transition that experiences the most stress; where it goes from being most flexible to rigid. It is also the part that gets all the wear.”
Schweighardt and his team are careful not to over-bend hoses, not least because Airgas’ least expensive hoses are a couple hundred dollars, but also because of the hazardous material or incredible amount of pressure contained within. “We have some fairly high stored energy inside our hoses,” says Schweighardt. “In our high-pressure hoses, there can be as much as 6,000 psi in there, so we want to take care of it and make sure it is working properly.”
Choosing the right connection
In the industrial gas industry, the Compressed Gas Association (CGA), a consensus organization comprised of members from all facets of the industrial and medical gases and equipment industry in the U.S.A. and Canada, determines the best and safest connections for liquefied, non-liquefied, dissolved, and cryogenic gases.
Its mission is to improve the manufacture, transportation, storage, transfilling, and disposal of industrial and medical gases and their containers by developing internationally recognized standards and practices, providing safety information about the chemical properties of gases, and providing training, leadership and advocacy to its members, and the industry as a whole.
“The CGA decides, in a very company- agnostic way, that certain connections should be designed in a certain way,” explains Schweighardt. “The CGA determines the direction of the threads, size, sealing mechanism and male-female parts for any connection, and you cannot interconnect anything that should not be interconnected.”
As per the standards set by the CGA, Airgas uses many dozens of different connectors and couplings that are specific to the material that is being used. For example, if the material is liquid nitrogen, there is a special type of fitting that is used for liquid nitrogen and nothing else. This is no accident. “Liquid nitrogen comes in at least four sizes,” he continues. “Three standard large sizes and one standard small size.
Obviously, if you try to connect the small coupling to the large tank connection, it won’t match up because of the size difference, but if you go get the liquid oxygen couplings, they won't match up either. This is because they were designed not to match up with a tank of anything but liquid nitrogen.”
The idea is to minimize or eliminate the risk of user-error, which, considering the properties of the materials, could have serious repercussions. “All Airgas products have a different special connection. This is true of all of the trucks and tanks that are delivered to our customers.”
When consulting for Airgas projects, Schweighardt considers the materials that are passing through the pipes, including extremely cold liquid hydrogen and possibly high temperature nitrogen. The company goes to great lengths to ensure that its operations are adhering to the strictest safety policies and procedures.
For example, to protect its employees and equipment, Airgas often uses a hose restraint safety system inside a flexible hose, comprised of an internal cable with check valves on both ends. In the event of a hose failure, the internal cable stops the hose from detaching and the built-in check valves snap into a closed position, cutting off the flow of the process fluid inside. “If a hose was to break, both ends of the hose would seal and the cable would prevent the hose from detaching and forming a ‘whip’, which could seriously harm someone,” says Schweighardt.
Education and collaboration
It is no secret that the industrial process industries often falter when it comes to transferring knowledge and providing mentorship to new engineers, technicians, and operators. As the ‘old boys’ hang up their safety goggles and disappear into the warm sunset of retirement, the new generation is sometimes left out in the cold, expected to ‘figure it out’ for themselves.
We asked our expert what Airgas is doing to facilitate knowledge sharing. "We have dedicated teams around the world," he tells us, "who facilitate knowledge transfer across different Airgas and Air Liquide companies. We take advantage of technology that allows us to share files and collaborate on projects, run webinars and encourage internal communication. Providing engineering and design assistance for Airgas projects is part of my job description because we want to mentor our new engineers who may not have a lot of real-world experience working with the materials, whether it is pipe, tube, valve or other.”
Additionally, in a company the size of Airgas, there is no shortage of internal experts and consultants who may be called upon to provide expertise to an internal project or team. “For most of our Airgas projects, there is always a pretty good-sized team. The project manager pulls everything together, but he can’t design the concrete, steel, pipe and electrical; there is no human on the planet with a professional engineering certificate in all those disciplines. So, we bring in the company experts to help him out. One person can’t build a USD$100 million plant alone.”
Diversity to keep it interesting
After nearly 18 years as an International Expert, we asked Schweighardt what he liked most about his new hybrid position. “I enjoy meeting people,” he replied. “I like visiting a client, seeing their plants and the facilities where they actually perform the work. In the same day, I could visit a company that welds pure platinum and then another that builds aluminum navy boats. We work with every type of welding that you could imagine, just a ridiculous variety of products, materials and techniques. Diversity, in a word. That is the best part of the job.”
About the expert
Fred Schweighardt is a National Project Leader and International Expert for Airgas, an Air Liquide Company in Houston, Texas. In this capacity, he is applying his extensive background in welding to the fields of industrial gas in fabricating and manufacturing. Prior to joining Air Liquide, he was employed as a pipe welder, heating plant engineer, and weld shop manager. Fred is the Chairman of the AWS A5S (shielding gas) committee and is also a voting member of ISO US TAG 44. Schweightardt graduated from the University of Utah with a BS in Welding Engineering Technology, and is an AWS Certified Welding Inspector.