Hydrogen fuel cell welding
We’re dedicated to the advancement of clean energy, specifically lowering emissions. Hydrogen fuel cell welding on three-pass heat exchange components for electric vehicles is one of our top concentrations. Hydrogen fuel cell weld testing is not a standalone service but part of each project. We can also assist with the development of your hydrogen production systems and hydrogen dispensing systems.
The growing demand for clean energy, including hydrogen fuel cell-powered vehicles and hydrogen fuel cell-refueling stations is a major reason the global fuel cell market will reach $20.2 billion by 2026, with an anticipated increase of 17.9% in sales per year.
TIG welding for clean energy industry
Tungsten inert gas welding or TIG welding (aka. gas tungsten arc welding) is the preferred welding method for hydrogen fuel cell components because it’s both an ultra-precise and ultra-clean process. TIG welding is a complex, manual method that necessitates an expert skill set as well as a passion for continuously improving those skills.
In TIG welding, two metals join together by heat from an arc created by a non-consumable tungsten electrode and a base metal. To protect against oxidation, Axenics uses an inert shielding gas of high-purity argon.
TIG welding offers a superior solution for welding critical joints, and for situations where small or exceptionally precise welds are required. TIG welding results in the best quality welds for hydrogen fuel cell components.
The three-pass heat exchanger fuel cells we can weld vary in diameters ranging from 1/16th-inch to ½-inch to 3-inch. The shell of the fuel cell is seamless stainless steel 310 schedule 40. However, within the welds, there can be a variety of stainless steel, ranging from 308, 316 and 310. The steel options have different diameters and varying thicknesses, ranging from .45-inch and .65-inch wall thickness to ⅞-inch diameter to 1.25-inch. The final shell is schedule 540 with 5/16-inch thickness.
The variations in stainless steel require a highly-skilled welder to alter the steel’s performance several times throughout the welding process, changing with the thickness of the steel wall. This process also involves exceptionally high pressure and matching high heat. Welders inspect the steel for possible gouges or other defects in material through the process. They use a borescope or internal camera to check progress. The quality control department performs a similar check after the welding.
As welds on hydrogen fuel cell components must remain ultra-clean, Axenics does this work in a Class 100 cleanroom. The room is vacuumed, dusted and inspected internally twice per week. An air purification/filtration system is used and the team inside wears special attire to avoid any skin that may flake from their bodies from getting into the environment. Tools are cleaned before going into the cleanroom. Regular air-quality testing occurs, ensuring miniscule dirt and dust particles aren’t in the space.
Weld testing on hydrogen fuel cell components
Axenics performs both non-destructive and destructive tests on every welding project, including weldments for three-pass heat exchanger hydrogen fuel cells. Some customers require a randomly-selected destructive test on the welds as well. Cutting, bending or flattening the weld occurs in order to ensure it comes apart in the correct manner. If a weld does not break down in its intended way, that means it wasn’t welded properly.
Types of testing methods include:
- Visual inspections (often combined with other testing methods)
- Helium leak testing for welds on three-pass heat exchanger fuel cells involves administering a vacuum on the various weldments. Then helium is sprayed in tiny amounts on potential leak areas. A Mass Spectrometer Leak Detector (MSLD) “pulls” helium into the welds. The MSLD sounds an alarm if there is a leak. Pressure helium tests use pressurized helium and a sniffer probe connected to the MSLD around potential leak areas. The sniffer probe pulls the helium through the leak and into the MSLD to sound the alarm.
- Dye penetration testing utilizes water pressure to identify leaks. In the case of hydrogen fuel cells, the component is filled with water or another liquid that has a dye added. Once the liquid hits a pressure higher than the working pressure for the cell, it holds there for a predetermined amount of time. Potential leaks are visible thanks to the dye.
- Ultrasonic weld testing is not common for us, but it’s a highly reliable procedure. Ultrasonic testing locates the exact position of a weld discontinuity more accurately than even radiographic testing (which uses x-rays to detect weld flaws).
Our team has 40+ years experience in clean energy technology for the alternative energy industry. Reach out today with any questions.
Precision welding, such as TIG welding, produces clean and exceptionally accurate welds. Precision welds are defined as the purest welds for joining tubes and fittings on both metals and plastics. A precision weld’s bead fully penetrates the inner wall of a tube,...