Hydrogen/methane release at a gas booster of a pipeline

The incident involves a gas booster provided by a manufacturer. This device is used in the experimental platform of the project to raise the pressure in pipelines from 60 to 80 barg (from 6 to 8 MPa), allowing the gas to flow in a close loop. After 5 weeks of operation, a critical gas leakage through the vent port was detected.

At the moment of the incident, the compressor was working with a mixture of hydrogen and methane (H2/CH4 blend 20/80 %v/%v). The booster was sent to the manufacturer for inspection and reparation. Severe damage in the seals of the vent port was found. Besides, the gas barrels were scratched. Both seals and gas barrels had to be replaced.

The reason for this failure is unclear and the manufacturer cannot provide a real solution. The booster must have been able to perform 2,000,000 cycles without premature deterioration of the seals, but failed after 500,000 cycles.

No consequences on people or property. Minor damage of environment because of release of greenhouse gases (methane)

The INITIATING cause of the release was the was the severe damage of the seals of the vent port, which occurred during operation.
The manufacturer could not provide a root cause of the damage.
The operator concluded that a manufacturing defect seems the most logical explanation for the failure. They also suspect that the manufacturer is reluctant to admit it, because the spare parts used after the reparation were the same as those originally installed.

booster

The device was new and had not been used previously. The event occurred during a planned operation (the first experimental campaign).

No consequences, no damage. 0.5 kg of H2 and 15.7 kg of CH4 released

As first corrective action, the seals and the gas barrels were replaced by the manufacturer.

The facility operator is considering changing the booster manufacturer, for the following reasons:
(1) It appeared that the booster is not suitable for working with hydrogen / methane blends, especially in closed setups, because they are not tight enough.
(2) Manufacturer after-sale service was not reliable. Also, they did not provide sufficient information on the cause of failure.
(3) The communication with the manufacturer is in general difficult, slow and requests are often ignored.
(4) Manufacturer factory is in the UK, and since the BREXIT supplies are stopped at the custom too long, which makes finding quick solutions even more difficult.

A general conclusion could be that problems related to suppliers - projects relationship can generate safety issues.