Your hydrogen fuel cell production should include weld testing to ensure compliance and high operability. It’s not uncommon for power cells such as three-pass heat exchanger hydrogen fuel cells to receive both non-destructive and destructive testing to ensure long-lasting operation. Axenics’ team has decades of experience in the sometimes rigorous demands of welding parts used in hydrogen fuel cells and the subsequent testing of those welds.
Non-destructive weld testing does not require erasing the functionality of a completed weld in order to determine its quality. For hydrogen fuel cell welds, we perform helium leak testing and dye-penetration or hydrostatic tests. These tests are designed to detect potential manufacturing defects, and to ensure the integrity of the welds to provide a safe product. Consumer safety is a top mandate at Axenics.
Helium Leak Testing
The helium leak testing process we use to test three-pass heat exchanger welds involves pulling a vacuum on the different weldments. Helium is then sprayed in tiny amounts on areas where there could be potential leaks. A helium leak detector a.k.a. Mass Spectrometer Leak Detector (MSLD) then “pulls” the helium into the welds. The MSLD sounds an alarm is there is a leak present.
Pressure helium tests can be performed by pressurizing welds with helium and utilizing a sniffer probe that is 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.
Hydrostatic Leak Testing
We also refer to this test as dye-penetration. Hydrostatic 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 that is higher than the working pressure for the cell, it is held there for a predetermined amount of time. The cell is then checked for potential leaks.
Demands for Hydrogen Fuel Cells
The byproduct of a hydrogen fuel cell is water, which is why those particular fuel cells are in high demand for alternative energy industries that operate machinery indoors. Companies are looking for more end products that use hydrogen motors, as there is less opportunity for air contamination from machinery using hydrogen fuel cells.
The three-pass heat exchanger fuel cells that Axenics welds for customers have varying diameters ranging from 1/25th-inch to ½-inch to 3-inch. The shell of the fuel cell is constructed from seamless stainless steel 310 schedule 40. However, within the same weldment, there are a variety of different metals, ranging from 308, 316 and 310, which is considered a specialty metal.
These metals also have different diameters and varying thicknesses,ranging between .45-inch and .65-inch wall thickness to ⅞-inch diameter to 1.25-inch. The final schell is schedule 540 with 5/16-inch thickness.
These variations in stainless steel requires a highly-skilled welder to be able to alter their performance several times throughout the welding process, changing with the thickness of the steel wall. This process also involves super high pressure and super high heat. In order to help ensure a top-quality final product, welders need to inspect the steel for possible gouges or other defects in material.
At Axenics, our welders use a borescope or internal camera to check our progress. The quality control department does a similar check, as we want your products to be functioning at 100 percent upon delivery.
To ensure parts for your hydrogen fuel cells are delivered at the highest quality, only our most experienced welders are working on them. Our welders are D17 certified by the American Welding Society. The reason why we have such high expectations from our welders – including schooling and years of field experience – is that there is literally no room for error when it comes to welding your hydrogen fuel cell components. When they arrive to you, these welds are flawless.