NECESSITY OF REMOTELY OPERATED SHUT OFF VALVES

Thousands of gallons of a highly flammable hazardous chemical spilled for nearly 30 minutes before catching fire at the Intercontinental Terminals Co. tank farm in Deer Park, but the facility did not have a remote emergency shutoff valve nor an alarm to alert workers, according to the U.S. Chemical Safety Board. Source: CSB

Have you studied your system to check the necessity of remotely operated shut off valves?

EXCESS FLOW VALVES MAY NOT WORK PROPERLY

More than 35,000 gallons of propane were released when the discharge hose on an LPG transport truck separated from its hose coupling at the delivery end of the hose, and none of the safety systems on either the truck or the receipt tank worked as intended to stop the release. The DOT determined that emergency systems such as EFVs do not always function properly when a pump is used to unload the protected vessel. If a release occurs downstream of the pump and the EFV activation point is greater than the pump capacity, the pump will function as a regulator limiting the flow to below that required to close the EFV. Courtesy EPA.gov

INCIDENT DUE TO FAILURE OF TWO EFV'S

A methyl mercaptan release occurred when a pipe attached to a fitting on the unloading line of a railroad tank car fractured and separated. Fire damage to cargo transfer hoses on an adjacent tank car also resulted in the release of chlorine gas. Neither of the two EFVs closed to control the release. Three plant employees were killed in the resulting explosion and several employees were injured. Approximately 2,000 local residents were evacuated from their homes for 10 hours. Failure of the EFVs to close contributed to the severity of the incident. The NTSB determined that the facility placed undue reliance on the tank car EFV to close in the event of a leak from the transfer line.Courtesy NTSB.gov

INCIDENT DUE TO FAILURE OF ESV

A chlorine railcar transfer hose ruptured, releasing 48,000 pounds of chlorine. Hundreds of residents were evacuated or sheltered-in-place, and sixty-three local residents sought medical evaluation; three were admitted to the hospital. The chlorine also damaged tree leaves and vegetation around the facility. The CSB determined that an excess flow valve internal to the chlorine railcar did not close, contributing to the severity of the event. As a result of such chlorine releases, the CSB has issued a recommendation to the Department of Transportation (DOT) to expand the scope of DOT regulatory coverage to include chlorine railcar unloading operations and ensure the regulations specifically require remotely operated emergency isolation devices that will quickly isolate a leak in any of the flexible hoses (or piping components) used to unload a chlorine railcar.Courtesy EPA

AUTO IGNITION INCIDENT

An oil spill occurred due to a failure of a block valve to seal properly during maintenance of a pump strainer in the visbreaker unit at a plant in Wickland, Aruba, Dutch Antilles in 2001. The oil auto-ignited and the ensuing fire spread and destroyed the visbreaker and damaged adjacent equipment. Estimated loss was USD 250 million current value. (Marsh)

REMOTE OPERATED ISOLATION VALVES

The Center for Chemical Process Safety has given some good guidelines for remote operated shut off valves. In Many incidents, the consequences are magnified as there was no remote operated shut off valve provided. In many fires and toxic gas releases, the manual isolation valves get engulfed and make it impossible to enter the area to operate the valves. Read the guidelines in this link:

https://www.aiche.org/ccps/remote-isolation-and-shut

Incident of failure of SDV

A recent incident involving the failure of a shut down valve (SDV), and the subsequent failure of two pressure safety valves (PSV), has highlighted issues associated with the selection of SDVs and the need for regular maintenance and testing of SDVs and PSVs.The failure occurred after an electrical supply fault caused an emergency shutdown of a gas processing plant. Upon subsequent start up of the plant and one of the plant’s compressors, an SDV passed on closure allowing the gas pressure to build up in a crossover header between high pressure and low pressure pipework systems. Another compressor was then started further increasing the pressure. Two PSVs in the gas line failed to operate at their set pressure and the pressure continued to rise until a rupture disk relieved to flare.
Courtesy: NOPSA
Read the safety alert in this link

Corrosion in Water Based Fire Sprinkler Systems

Good article!
https://www.facilitiesnet.com/firesafety/article/The-Hidden-Threat-of-Corrosion-in-WaterBased-Fire-Sprinkler-Systems--18984