At VES we manufacture custom leak testing systems that integrate into your production line.
The high-pressure generation unit (HPGU) is housed within a custom ISO shipping container.
The HPGU charges a hydrogen tank with a test pressure ranging from 350 to 700 bar with a 5% helium and 95% nitrogen tracer gas mixture (which translates to significant savings by not using 100% helium) for use in the leak test module (LTM).
The high-pressure generation unit receives the tracer gas mixture, which is stored at low pressure, around 10 barg, in a low-pressure gas recovery module. The tracer gas is then compressed to 350 barg and stored.
A portion of this 350 barg tracer gas is compressed to 900 barg and stored. The tracer gas is used to pressurize the hydrogen tank during the leak test within the plant, feeding the tracer gas to the leak test module (LTM). The hydrogen tank is initially filled from storage tanks pressurized to 350 barg to an intermediate pressure. Once this process is complete, the hydrogen tank is filled to the test pressure from the 1000 barg gas storage. For larger hydrogen tanks that require a test pressure higher than 700 bar, a third stage is included where the hydrogen tank is filled directly.
Once the leak test cycle is completed within the leak test module, the hydrogen tank is emptied via the tracer gas recovery module. This allows the system to reuse the gas used during the high-pressure hydrogen tank leak test.
During this leak test process, a cooling unit is in charge of cooling the tracer gas during the process stages.
The Leak Test Module (LTM) is responsible for verifying the tightness of the high pressure hydrogen tank through a mass spectrometer.
The high-pressure hydrogen tank is placed within the hydrogen tank leak test chamber and connected to the test gas line originating from the High Pressure Generating Unit (HPGU). The tank is then filled with tracer gas up to the specified test pressure, while the leak test chamber is evacuated by vacuum pumps.
A nitrogen purge is then carried out in the leak test chamber, creating a vacuum to remove any background contamination within the chamber. Once the vacuum is achieved, the mass spectrometer detects any helium leaks from the hydrogen tank.
Once the hydrogen tank leak test cycle is complete, the tracer gas is sent back to the HPGU. The hydrogen tank is then removed from the leak test chamber before loading the next tank for the cycle to be repeated in a new tank.
A preliminary test is also conducted by filling the leak test chamber with a specific amount of tracer gas, without the hydrogen tank present. This test is performed to ensure the mass spectrometer is functioning properly and is calibrated correctly. The test is performed using low-pressure gas from the HPGU.
The Leak Test Module (LTM) is housed within its own safety box.
The components for high-pressure gas generation and processing are housed in two ISO-standardized transport containers, specially designed to simplify logistics and installation.
The high-pressure gas unit (HPGU) is designed to pressurize hydrogen tanks up to 700 bar (or 875 bar for individual tests), using forming gas, a combination of 5% hydrogen and 95% nitrogen, for the hydrogen tank high-pressure leak test within the Leak Test Module (LTM).
Once the test cycle is completed, the pressurized forming gas is stored at low pressure, around 10 barg, before being compressed and stored at 330 barg. A portion of this 330 barg pressurized forming gas is compressed and stored at 1000 barg, later being used to fill the hydrogen tanks within the two leak test modules.
Hydrogen Fuel Tanks are filled from two 330barg storage units at an intermediate pressure, then fully filled from the 1000barg gas storage to increase the pressure to the specified test pressure. This operation is part of the high-pressure gas storage process.
After the testing cycle within the Leak Test Module (LTM) is completed, the forming gas inside the hydrogen tank is evacuated through the drain panel. The system reuses the forming gas released from the hydrogen tank up to 30 barg pressure, the remaining forming gas is vented to the atmosphere.
Once the test cycle is complete, the pressurized forming gas is stored at low pressure, around 10 barg before being compressed and stored at 330 barg as part of the high-pressure gas storage process.
A portion of this pressurized forming gas at 330 barg is compressed and stored at 1000 barg, it is then used to fill the hydrogen fuel tanks within the two Leak Test Modules as part of the advanced high-pressure gas storage process.
The Leak Test Modules (LTM) are housed in a safety interlocking room, with both modules designed to test the tightness of hydrogen fuel tanks while being filled with high-pressure forming gas.
The hydrogen fuel tank is initially loaded into a Gas Testing Fixture (GTF) that positions and ensures the tank is ready to be connected to the loading conveyor, and then to another conveyor that will place it into the vacuum chamber.
Hydrogen fuel tanks are automatically scanned by a barcode as they pass through the conveyor before being placed in the vacuum chamber. Once the hydrogen fuel tank is inside the vacuum chamber, the bolts are activated to lock the Gas Testing Fixture (GTF) in its correct position before an automatic coupling connects the GTF to the rest of the system.
Each of the gas test modules can hold up to four hydrogen fuel tanks at the same time to perform the leak test.
The vacuum chamber is closed, and the air is evacuated, creating a vacuum inside the chamber. The hydrogen fuel tanks are also vacuumed, but a difference between the tank pressure and the vacuum chamber pressure is first established to perform a leak test. If no leaks are found, the hydrogen fuel tanks are completely vacuumed and then rapidly pressurized with forming gas.
Once the gross leak test has been completed, the hydrogen fuel tank is filled with forming gas prior to being pressurized for the preset leak test. Once the leak test cycle is completed, the forming gas is recovered from the hydrogen fuel tanks, returned to the High Pressure Gas Unit (HPGU), and stored.
Included in the complete leak test cycle is an initial leak test, which is done by introducing a quantity of nitrogen into the vacuum chamber while no hydrogen fuel tank is inside the chamber. This initial leak test ensures that the mass spectrometer is functioning correctly and calibrated within the required parameters. This preliminary test uses low-pressure gas from the High Pressure Gas Unit (HPGU).
The two Leak Test Modules are housed in a safety-locked test room.
The High Pressure Gas Generation Unit (HPGU) houses gas storage and processing components within two completely independent containerized solutions with ISO certification. This design simplifies transport and installation.
The gas storage container accommodates all the gas storage modules, serving both to fill the high-pressure tanks (HPV) and to recover the forming gas.
Within the storage container, gas storage is divided into four independent areas. These comprise the low-pressure recovery module, the intermediate gas storage unit, two gas recovery storage units, and finally, the high-pressure storage unit.
This container also accommodates the fuel supply panel which routes high-pressure gas from the HPGU to the Leak Test Module (LTM). A recovery panel directs the flow to the low-pressure gas recovery module from all fuel-draining panels and the low-pressure gas recovery module.
The Leak Test Module (LTM) is responsible for verifying the tightness of the high pressure hydrogen tank through a mass spectrometer.
The high-pressure hydrogen tank is placed within the hydrogen tank leak test chamber and connected to the test gas line originating from the High Pressure Generating Unit (HPGU). The tank is then filled with tracer gas up to the specified test pressure, while the leak test chamber is evacuated by vacuum pumps.
A nitrogen purge is then carried out in the leak test chamber, creating a vacuum to remove any background contamination within the chamber. Once the vacuum is achieved, the mass spectrometer detects any helium leaks from the hydrogen tank.
Once the hydrogen tank leak test cycle is complete, the tracer gas is sent back to the HPGU. The hydrogen tank is then removed from the leak test chamber before loading the next tank for the cycle to be repeated in a new tank.
A preliminary test is also conducted by filling the leak test chamber with a specific amount of tracer gas, without the hydrogen tank present. This test is performed to ensure the mass spectrometer is functioning properly and is calibrated correctly. The test is performed using low-pressure gas from the HPGU.
The Leak Test Module (LTM) is housed within its own safety box.
The Leak Test Module (LTM) is part of the overall High-Pressure Generation Unit (HPGU) system that tests the air-tightness of high-pressure hydrogen fuel tanks (HPV).
High-pressure tanks are first loaded into a Gas Test Fixture (GTF) and then automatically guided by a conveyor to the loading dock where the QR codes of the tanks and the RFID codes of the GTFs are automatically scanned for tracking purposes. The Gas Test Fixture (GTF) is elevated and transported to the vacuum test chamber on a conveyor. Once safely placed within the chamber, the GTF is automatically coupled and connected.
Each Gas Test Fixture contains 4 high-pressure tanks for the leak test. When the tanks are in position, the program first creates a vacuum within the chamber, then runs a gross leak test by pressurizing the tank with a set amount of gas. Once the gross leak test is completed, the hydrogen fuel tank is filled with forming gas before pressurizing it again to carry out the pre-set leak test.
Upon completion, the hydrogen fuel tanks are emptied in stages inside the vacuum chamber, but mainly at one of the two external fuel drain stations.
Once the hydrogen fuel tank reaches a set pressure within the chamber, the load line is purged before decoupling the GTF. The locking couplings are then actuated to release the GTF and it is transported to an external drain station by the conveyor. Once the tank is emptied, it is conveyed back to the loading zones for removal from the Leak Test Module (LTM).
As part of the leak test, a known amount of tracer gas is injected into the vacuum test chamber when no hydrogen fuel tank is present. This test ensures that the mass spectrometer is working correctly and is calibrated in the correct range.
For hydrogen tank manufacturers demanding the highest safety standards, VES provides custom leak testing systems that provide accurate and reliable leak detection, seamlessly integrated into your production line.
Certified to meet R134 and TCATSI standards, our solutions are modular in design and can be scaled to your production needs.
Whether you’re interested in learning more about our solutions or already have a specific need in leak detection for Hydrogen Fuel Tanks, send us an email. We promise to get back to you within 24 hours.
We are the next generation in Leak Testing Machines
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