SMALL THINGS MATTER IN ASSET INTEGRITY!

On January 21, 2023, at 4:30 p.m., 30 pounds of hydrogen gas were accidentally released from a shell-and-tube heat exchanger at a refineryin Louisiana. The released hydrogen caught fire, leading to an emergency shutdown, and caused over $1.5 million in property damage.
The hydrogen release originated from the flange between the heat exchanger channel and shell and occurred during unit startup. The heat exchanger was assembled in 2013 and had undergone 43 thermal cycles. During that time, the bolts had relaxed (a normal event) but had relaxed to the point that the flange could no longer contain the hydrogen within the heat exchanger. The company's investigation found that the bolt torque value used to assemble the heat exchanger in 2013 was too low and should have been much higher to prevent leakage.

CITGO found that the assembly instructions for both the incident heat exchanger and a nearby similar heat exchanger listed incorrect torque values that were too low, as the instructions listed the wrong bolt sizes. In addition, CITGO suspected that since it is common practice at the site to assemble similar flanges to similar torque values, the incorrect torque instructions from the nearby heat exchanger may have been applied to the incident heat exchanger. The company determined that the hydrogen may have ignited from contacting an adjacent hot heat exchanger, friction from the release, or a spark.
Probable Cause
Based on the company's investigation, the CSB determined that the probable cause of the incident was under-torqued bolts that had relaxed during 43 thermal cycles until the flange could not contain the hydrogen within the heat exchanger. Inaccurate assembly instructions and the likely application of incorrect assembly instructions for another heat exchanger contributed to the incident.

Source: CSB.gov

WAKE UP, INDIA'S CONSCIENCE!

 WAKE UP, INDIA'S CONSCIENCE!

AI 171 crash June 12 , 2025- aviation sector - 261 killed
Sigachi Industries blast June 30, 2025 - Chemical sector - Over 42 killed
At the outset, my heartfelt condolences to the familes of those who perished in these unfortunate incidents. Nothing can bring back the people who died. The immense grief of the families is unfathomable.

This is a post to highlight how the Indian media, society and regulators treat the two incidents differently.

Strata of society of the people who perished:

AI 171 crash: Those who could afford an international air ticket and some people on the ground.

Sigachi Industries blast - mostly migrant labourers and few operators and supervisors.

Media coverage:

AI 171 crash - Media coverage still hot and on going

Sigachi Industries blast - Interest for about 2 weeks and then died down

Press conferences by regulatory bodies:

AI 171- Continued involvement of both central and state governments

Sigachi Industries blast - a few by the authorities.

Incident invesigation:

AI171 Crash - Investigation ongoing as per ICAO guidelines.Preliminary report made public within 30 days

Sigachi Industries blast - committee formed but no report made public yet.

QUESTIONS:
Isn't the life of a migrant worker, operator, supervisor in a chemical industry the same as an air passenger?

Why is there no PSM rule implemented in India as a regulatory requirement? Though efforts have been made in the oil and gas sector, still most of the other sectors in the chemical industry are left out.

Why isn't an incident in the chemical sector investigated by an independent body reporting to the highest levels of government and reports made public?

Why, after more than 40 years of the Bhopal disaster, we still have to struggle to obtain incident investigation reports of incidents in the chemical sector in India? Some of the available reports do not delve down to the organizational issues including culture and accountability.

Are we waiting for a bigger chemical disaster than Bhopal to wake up?

Introspect and act!

CHECK THE DIRECTION OF ROTATION OF YOUR BATTERY OPERATED TOOLS - THEY MAY CAUSE AN INCIDENT!

On January 17, 2023, natural gas liquid was accidentally released during maintenance of a natural gas liquid storage cavern in Texas. The released natural gas liquid formed a vapor cloud and ignited, causing a large fire. The fire fatally injured one contract worker and seriously injured another. The company estimated the property damage from the incident to be $3.1 million.
The gas storage cavern was used to store natural gas liquid (a mixture of mostly propane and butane). At the time of the incident, contractors were securing components of the wellhead after a maintenance operation and needed to tighten eight lockdown screws into the wellhead. A contractor used a battery-operated impact wrench, which was inadvertently left in reverse. When the contractor attempted to tighten one of the lockdown screws, the screw was accidentally removed, releasing natural gas liquid. This flammable material ignited, injuring the two workers. Both workers were transported to the hospital, where one succumbed to the burn injuries.

Cavern seals were in place for the maintenance work, which prevented any release from the cavern itself. When the lockdown pin was removed, the residual natural gas liquid was released from the hydraulic workover unit, referred to as a “snubbing unit,” which was being used for the maintenance operation. The pressure in the snubbing unit at the time of the incident was 400 pounds per square inch gauge.It was estimated that 16 barrels of natural gas liquids were released. After the incident, the company created action items to require (1) using hand tools to adjust lockdown screws on cavern wellheads and (2) establishing risk management practices to vent pressure from the snubbing unit to the flare system.
 

Probable Cause
Based on the company investigation and  OSHA inspection, the CSB determined that the probable cause of the accidental release of natural gas liquid was the inadvertent removal of a lockdown screw from the wellhead. Contributing to the incident was the use of a battery-operated impact wrench and the presence of pressurized natural gas liquid in the snubbing unit.

Source:CSB.gov

THE IMPORTANCE OF OPERATION READINESS REVIEWS

 On January 17, 2023, at 10:45 p.m., 670 gallons of hot water were accidentally released and pooled at a facility in Louisiana. One employee was seriously injured after stepping into the pool of hot water.

The investigation of the events leading up to the incident began on January 9, 2023, when the facility planned maintenance work on a control valve in the boiler feedwater piping system. Operators observed water leaking past two valves in series, upstream of the control valve, when in the closed position. To allow for control valve maintenance, site personnel developed and executed a plan to route leaking boiler feedwater out of the system by opening two bleed valves (in series) between the leaking valves. Site personnel attached a hose to the bleed valve piping to route the leaking hot boiler feedwater to a nearby sump.
On January 17, 2023, after maintenance work on the boiler feedwater control valve was completed, operators were tasked to recommission the control valve. At about 8:00 p.m., operators lined up valves in the piping system so the control valve could be returned to service. The operations personnel did not use the site’s operational readiness checklist, which included requirements for personnel to evaluate or “walk down” the piping and valve lineup to ensure correct positioning before startup. As a result, when hot feedwater was re-introduced to the piping, the bleed valves remained open, and the temporary hose remained connected to the piping. Hot boiler feedwater began releasing through the open bleed valves and hose.
At 10:46 p.m., the control board operator observed a low boiler feedwater pressure alarm and requested an outside operator to investigate. Personnel identified that the boiler feedwater piping was the source of the low-pressure alarm and, realizing there was a leak, closed an upstream valve to stop the leak. About 670 gallons of hot water were released. At about 11:45 p.m., an outside operator attempted to close the two open bleed valves and inadvertently stepped into a pool of the hot boiler feedwater that had accumulated in a depression. The high-pressure boiler feedwater release may have created or enlarged this hole. The operator was seriously injured when his lower leg was submerged in the hot water above the top of his rubber boot, and the hot water contacted his lower leg and foot.

Probable Cause
Based on the comapny's investigation, the CSB determined that the probable cause of the incident was starting up the boiler feedwater piping system with open bleed valves connected to an open-ended hose, allowing hot water to release and accumulate. An operator subsequently stepped into the pooled hot water, receiving burns to his lower leg and foot. The ineffective application of the operational readiness checklist contributed to the incident by not ensuring that the bleed valves were closed and the hose was removed before the startup.

Source: CSB.gov

TRAPPED AMMONIA CAUSED AN INCIDENT DURING MAINTENANCE

 On January 7, 2023, at approximately 4:55 p.m., about one pound of anhydrous ammonia was released at the a Meats facility in Iowa.
At the time of the incident, the employee was working on an out-of-service ammonia compressor used in the refrigeration system. The compressor had been previously isolated from the system, and the ammonia was understood to have been removed entirely.
When removing the bolts on the flange connecting the outlet piping to the compressor, a burst of ammonia vapor was released directly into the employee’s chest and face. The employee was not wearing respiratory protection because the ammonia compressor was understood to be empty. The injured employee was taken to a hospital for treatment of the ammonia exposure injuries he suffered.
The company's investigation found that the company’s ammonia removal procedure allowed some ammonia to remain trapped between the compressor’s discharge check valve (a valve that only allows for single-direction flow) and an isolation valve. Another valve needed to be opened to remove ammonia from the isolated piping. It was determined that this valve had remained closed because the procedure did not include this valve.

Based on the company's investigation, the CSB determined that the probable cause of the anhydrous ammonia release was disconnecting the outlet piping from the ammonia compressor while some ammonia remained within the equipment. The company’s ammonia removal procedure contributed to the incident because following it did not effectively remove the ammonia from the compressor.

Source:CSB.gov