Liquid Hydrogen Refueling Operational Incident

First Name
Andy
Last Name
Piatt

Incident Synopsis
While disconnecting a liquid H2 fill line from a liquid H2 trailer, liquid H2 escaped, burning a second man who was holding the hose. The man was burned on his hands and on his stomach.

Cause
The liquid H2 shut off valve was partially open, but both men assumed it was closed. Prescribed clothing was being worn.

Hydrogen Delivery Truck/ Facility Connection Mishap

First Name
Andy
Last Name
Piatt

Incident Synopsis
During transfer of liquid H2 from a commercial tank trailer to a receiving vessel, a leak developed in a bayonet fitting at the trailer/facility connection. The leak produced liquid H2 spray which enveloped the rear of the truck where the hand-operated shutoff valve was located. Emergency trained personnel, wearing protective clothing, except for proper shoes, entered the area and shut off the flow control valve. Reentry personnel suffered frost bite of their feet when shoes became frozen to the water-wetted rear deck of the truck.

Needle Valve Failure in Hydrogen Service

First Name
Andy
Last Name
Piatt

The subject needle valve was used primarily for manual filling to control the flow rate of hydrogen from storage banks to the 70MPa test system. The valve was installed on the exterior of the thermal chamber in ambient temperatures of -5C to +30C. The gas flowing through the valve was at conditioned temperatures of -40C to +50C. The valve was in service for approximately two years and 400 fill operations.

Hydrogen Boosting Compressor Fails

First Name
Andy
Last Name
Piatt

A single-stage diaphragm compressor failed during boosting of high-pressure hydrogen ground storage banks. The compressor sources hydrogen from a 44 MPa storage bank as suction and discharges it at a stop set point of 85 MPa. The compressor capacity is 0.71 m3/min (25 scfm).

Fueling Hose Fails

First Name
Andy
Last Name
Piatt

A sidewall burst failure of a high-pressure polytetrafluoroethylene-lined hose was experienced. The 4.0-m hose was in service for approximately two years, primarily for 70 MPa fueling of hydrogen at ambient conditions ranging from -40 C to +50 C. The total number of fills during its service life was estimated to be 150. In addition to the high-volume fill events, pressure cycling occurred as part of the routine test procedures and operational protocols. These additional pressure-cycling occurrences were approximated to be 200-250 cycles.

Compressor Fastener Failure

First Name
Andy
Last Name
Piatt

The System Shutdown logic activated and the compressor automatically shut down on high vibration. When the operator investigated the unplanned shutdown, two broken compressor head fasteners were noted lying on the deck.

Incorrect Check Valve Installation

First Name
Andy
Last Name
Piatt

The contractor was replacing a needle valve and a check valve on the nitrogen purge line to the dispenser because of a small leak at the connection between the needle valve and the check valve. On reinstalling the valves, the contractor installed the check valve backwards, causing the pressure disk in the regulator to fail, venting about 1000 psig hydrogen into the air for about 10 seconds. This was found during testing of the contractor's work before the system was returned to normal service.

Fire at Hydrogen Fueling Station

First Name
Andy
Last Name
Piatt

A fire began in the compression skid for a high-pressure hydrogen fueling station. The initial source of fire was likely a release of hydrogen from a failed weld on a pressure switch. The initial fire cascaded to three stainless steel line failures, release of glycol coolant, and release/combustion of compressor oil. Non-metallic seals and hoses containing hydraulic fluid and coolant melted/burned and caused leakage of the fluid, which was mostly consumed by the fire.

Subscribe to Fueling Station