Product Information

Metal Gasket Fittings for Ultra High-Pressure Hydrogen Gas

2017 Cho Monodzukuri Grand Award for Parts, 14 consecutive years of awards, Machinery Award, Metal Gasket Fittings for Ultra High-Pressure Hydrogen Gas

In the 14th Cho Monodzukuri Grand Award for Parts (organized by The Monodzukuri Nippon Conference and Nikkan Kogyo Shimbun), Fujikin's Metal Gasket Fittings for ultra high-pressure hydrogen gas was awarded the Machine Parts Award. As a result, Fujikin has now been awarded for 14 consecutive years. These products are fittings for ultra high-pressure hydrogen gas used in the configuration of hydrogen stations, which prevent external leaks after a long time and contribute to safe operation. They also have excellent operability and maintainability, and shorten the amount of time for piping construction by half compared to products used up to now.

1. Details and features of the product

These products are fittings for use with ultra high-pressure hydrogen gas. They are used for the safe operation of hydrogen stations and prevent external leaks from the high pressure hydrogen gas which is used in equipment such as the pressure intensifier, pressure accumulator and dispenser for replenishing hydrogen in fuel cell vehicles.

When replenishing hydrogen in fuel cell vehicles, general consumers handle high pressure hydrogen at 82MPa in the hydrogen station, and high reliability is required from the pipe fittings used in the equipment to ensure pressure resistance and no external leaks.

However, cone & thread fittings (diagram 1) which are currently commonly used in hydrogen stations have poor reliability against external leaks, and due to problems with operability and maintainability, customers have not been satisfied.

Diagram 1. Cone & thread fitting

Diagram 1. Cone and thread fitting

On the other hand, there are metal gasket fittings (diagram 2) which have been developed for use in semiconductor manufacturing and this existing technology has excellent reliability against external leaks. However, they have a problem in that they cannot maintain their seal in shell tests at design pressure (82 MPa) × 1.5 times required by the high pressure gas safety act for hydrogen gas filling, which is the planned pressure (82MPa) x 1.5.

Diagram 2. Metal gasket fitting used in semiconductor manufacturing

Diagram 2. metal gasket fitting used in semiconductor manufacturing

In order to solve these problems, we revised the structure of the metal gasket fittings for semiconductor manufacturing, and by improving the seal component, we were able to obtain sufficient pressure resistance and airtightness against the filling pressure in hydrogen stations. With this, we were able to develop and commercialize the metal gasket fittings for ultra high-pressure hydrogen gas which also have excellent construction performance and maintainability.

Diagram 3. Structure of a metal gasket fitting for ultra high-pressure hydrogen gas

Diagram 3. Structure of a metal gasket fitting for ultra high-pressure hydrogen gas

2. Evaluation items

2-1. Creativity of technology

Table 1 shows the technical superiority compared to prior technology

Table 1. Comparative evaluation result (using high-pressure piping of hydrogen station) for metal gasket fittings for ultra high-pressure hydrogen gas, cone & thread fittings, for metal manufacturing equipment for semiconductor manufacturing equipment

Table 1. Metal gasket fittings for ultra high-pressure hydrogen gas, cone & thread fittings, fittings for semiconductor manufacturing equipment Diagram 4. Metal gasket fitting for semiconductor manufacturing / Diagram 5. Metal gasket fitting for ultra high-pressure hydrogen gas

2-2. Performance

Table 2 shows the assessment results at the time of development. Good results were obtained for all items and it was confirmed that there are no problems in using these fittings for high pressure hydrogen gas in hydrogen stations.

Table 2. Assessment results for the metal gasket fittings for ultra high-pressure hydrogen gas

Table 2. Assessment results for the metal gasket fittings for ultra high-pressure hydrogen gas

2-3. Economy

Comparing the adoption of these fittings to the prior technology, it can be expected that the construction points for the fittings are reduced, space for the pipe arrangement is reduced (diagram 8), and there will be an improvement in the removability during equipment maintenance (diagram 9). There will be an economical effect when constructing and maintaining the hydrogen station.

Diagram 8. Comparison of pipe arrangement examples for cone & thread fittings and metal gasket fittings for ultra high-pressure hydrogen gas

Diagram 8. Comparison of pipe arrangement examples for cone & thread fittings and metal gasket fittings for ultra high-pressure hydrogen gas

Diagram 9. Comparison of the attachment / detachment process for cone & thread fittings and metal gasket fittings for ultra high-pressure hydrogen gas

Diagram 9. Comparison of the attachment / detachment process for cone & thread fittings and metal gasket fittings for ultra high-pressure hydrogen gas

2-4. Achievements and forecast for future circulation

This product has been used in hydrogen stations since 2016, and it is planned to continue adoption from 2017 onwards.

Furthermore, with the "revision of the hydrogen and fuel cell strategy roadmap" by the Agency of Natural Resources and Energy​, a target has been set to establish more hydrogen stations (160 by 2020, 320 by 2025), and the market is expected to grow.

2-5. Safety and environmental considerations

By adopting this product, it is possbile to prevent leaks in the equipment installed in the hydrogen station for a long time, and it also contributes to the safe operation of the equipment by improving operability during equipment inspections and replacements.

3. Related patents

Patents (registration complete):10 items

  • 1 item (pending)
  • 19 items (registration complete)