OSHA ASSET INTEGRITY OBSERVATIONS

Examples of equipment cited for violations of the PSM MI requirements that OSHA found during NEP inspections include:

• A broken gate valve caused a level gauge to not work properly, which rendered visual verification of liquid level for the vessel ineffective. This deficiency went uncorrected.
• The installation of an engineered clamp failed to correct a deficient piece of process piping, which was a 90-degree elbow that was outside acceptable limits. The employer continued to use the leaking 90-degree elbow as part of a piping circuit that conveyed waste hydrogen sulfide gas.
• Hydrogen sulfide monitors were not inspected and tested on a regular basis to correct deficiencies in alarms that were outside acceptable limits due to bad sensors, loose wiring, or monitors that needed to be replaced. Work orders were not managed by a tracking system to ensure that deficiencies were fixed in a timely manner. Some work orders marked “fix today” or “ASAP” were not fixed for a week or longer.
• Six relief systems in an alkylation unit were incorrectly sized and were not corrected in a timely manner when the deficiencies were reported. No Management of Change (MOC) was performed to justify the decision to delay replacing the deficient systems.
• Grounding cables were removed from equipment, such as a heat exchanger and pump motors, but were not replaced. 
• Excessive vibration was observed on motors with visible movement of structural steel decking and supports. Also, two 1” pipes and one 4” pipe containing flammable liquid were not adequately supported

Source: Osha.gov

ASSET INTEGRITY ISSUES

Failure to correct equipment deficiencies that are outside acceptable limits39 is one of the leading causes of PSM non-compliance in the petroleum refinery sector. Non-compliance for equipment deficiencies broke down into four major groups:

1. Lack of proper maintenance or repair, 38. 29 CFR 1910.119(j)(1)(i)-(vi)39. 29 CFR 1910.119(j)(5)OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION18
2. Inappropriate installation (such as inappropriate sizing),
3. Missing protective system (such as not including relief devices), and
4. Insufficient structural support.

Equipment most commonly cited for deficiencies were relief devices, followed by piping circuits, pressure vessels, and alarm systems.

Source:Osha.gov

 

Dust collector system explosion

Employee #1 was feeding 400 lb of granular polyalphamethyl styrene (CAS 25014-31-7) through a Mikropal #3 micropulverizer (equipped with a .032 in. screen) into a Mikropal Mikro-Pulsaire dry dust collector. The Mikro-Pulsaire unit has a continuously self-cleaning bag filter located inside the building and had no provision for explosion relief or venting. Apparently a piece of metal between 1 and 2 in. got past the magnet in the micropulverizer, ignited the dust in the system, and caused a fire and explosion that blew open the access door to the dust collector. Employee #1 was standing about 10 ft from the door and sustained second- and third degree-burns on his hands and face. 

Source:Osha.gov

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

Fatality due to inadvertent reaction

Employee #1, the basement operator at a powerhouse, was purging the liquid residue from the betene entrainment tank to the #16 boiler. Water and steam inadvertently got into the knockout pot, and materials that react to water, such as, but not limited to, acetic anhydride and diketene were in the tank. A reaction occurred, releasing flammable and hazardous materials into the atmosphere through a safety relief valve. The pressure relief device was only sized for an external fire, not a chemical reaction. As a result, the safety relief valves could not withstand the reaction. The overpressurization caused the steel pot to fail and explode. Employee #1 was killed.
Source:OSHA.GOV

Follow procedures for recomissioning mothballed equipment

https://www.nopsema.gov.au/assets/Safety-alerts/Alert12.pdf

Blog 50 – Be the Process Safety Change You Want to See - News - Process Safety Matters

Blog 50 – Be the Process Safety Change You Want to See - News - Process Safety Matters

VALVE MAGAZINE - mistakes and misconceptions in valve leak testing

This is a good article. Many times, the points mentioned in the article are missed.

https://www.valvemagazine.com/magazine/sections/features/7388-mistakes-and-misconceptions-in-valve-leak-testing.html

Incident due to improperly ventiliated confined space

When I was a shift engineer, I entered a confined space, a pressure vessel, after obtaining necessary work permit. After I entered, I climbed up the internal fixed ladder to inspect a demister located at the top. As I was climbing up, the CO alarm in my personal gas monitor went off and I evacuated the vessel. Investigation determined that  during the purging process after plant shutdown, one part of an isolated pipeline connected with the vessel had not been been purged. When a valve connected to this pipeline was opened by an operator when I was inside, the pocket of trapped gas entered the vessel.

Lesson: Confined space entry can pop up surprises, even after receiving work permit. Ensure your personal gas monitor is working properly before you enter a confined space. It saved my life!

Explosion due to Ammonia vapour

A storage tank for aqueous ammonia solutions was up for maintenance (replacement of the bottom part). After mechanical completion of the replacement work, a trial had been undertaken to fill the tank up, but overpressure was registered and the flange connecting the feeding line to the tank leaked. The problems were reported to the maintenance department, the flange connection was repaired and the pressure relief line checked, the trial to fill the tank was not reported to the shift supervisor. The next day a safe work-permit was issued to the mechanics to disconnect the piping associated with this tank for further repair. The repair work proceeded and during the grinding of a disconnected pipe, a mechanic noticed a whistling sound and hid, together with the other mechanics, behind a concrete tankfarm wall. Soon afterwards the tank exploded. The top of the tank was blown over an adjacent building and the office buildings, and bumped into another office building (approximately 60 m away), which was empty. The explosion is believed to be caused by the ignition of ammonia vapour caused by the repair works. Also the pressure relief line failed to perform as expected.
Lessons
1. Improvement of procedures.
2. Improvement of communication.
3. Improvement of training of personnel.
4. Re-design of vapour relief lines.
Source:COMMUNITY DOCUMENTATION CENTRE ON INDUSTRIAL RISK, MAJOR ACCIDENT REPORTING SYSTEM LESSONS LEARNT FROM ACCIDENTS NOTIFIED, INSTITUTE FOR SYSTEMS ENGINEERING AND INFORMATICS, COMMISSION OF THE EUROPEAN COMMUNITIES JOINT RESEARCH CENTRE, 1991, ISBN 9282622894.

Investigation report of the High Power committe on LG Polymers Visak incident

Things are changing for the good in India. After the Jaipur oil terminal fire was made public, the report of the high power committee of the incident at LG Polymers site at Visakhapatnam,AP has been made public by the Chief minister of A.P
The report is exhaustive and has lot of annexures. One of the issues is the lack of enforcement of facility siting rules. Habitats are permitted to be built near to the plant by the authorities and this makes it a disaster waiting to happen.
I hope the recommendations of the committee are implemented in a time bound manner.
Read the complete report in this link
https://www.ap.gov.in/?page_id=43744

Confined space incident

Three men inside a reactor vessel experienced breathing difficulties. They had inhaled vapour containing 1,1,1-trichloroethane as a result of using a cleaning agent in a poorly ventilated confined space. The three men were taken to hospital for observation and tests. They were discharged on the day following the incident and returned to work fully recovered two days later.The incident resulted from using a hazardous cleaning solvent in an inadequately ventilated confined space. The solvent contained 1,1,1-trichloroethane a harmful substance which should not be inhaled. In addition to the air flow being inadequate to effectively dilute the solvent vapours, the direction of ventilation was wrong. For this heavier than air vapour the air flow should have been from the top downwards.

Lessons
1. No cleaning agents containing solvents should be used in restricted spaces - such as tankers, columns, reactors, large pipelines etc. For the weld testing, water should be used instead of solvent based agents. Investigations should take place as to whether a harmless test process could be used instead of the dye disclosure method.
2. When using a solvent based cleaner, adequate air supply and ventilation should be ensured. If the fumes are heavier than air, they should be extracted from below.
3. If the ventilation is insufficient, independent breathing apparatus must be used.
4. If possible, work should not be carried out on a vessel at the same time as work in the vessel. If this is unavoidable, the persons working inside should be informed of the nature and scope of work being carried out on the outside. We should also check that safety measures governing work in tanks are adequate. A special co-ordinator is required for this.
5. On medical recommendation, various medications should be kept on site, such as Folon A 200 mg injection ampules and Auxilosan measured dose aerosols.
6. All jobs should be carefully planned from beginning to end. Deviations from the plan should require formal authorisation at a high level. Existing work permits should be withdrawn and new permits issued to cover the change in scope. There is a tendency to take less care towards the end of a job as the pressure to recommission plant and equipment increases.
7. The site policy on the use of solvents (and other hazardous chemicals) should be made absolutely clear to everyone who could be affected by their use. Inherent methods of enforcement of the policy should be devised. e.g. if particular solvent based cleaners are not allowed on site the purchasing system should prevent orders for them from being processed.
Source:ICHEME

Have you assessed all the hazards?

Many accidents and fatalities occur during the erection of new equipment in chemical plants. These can include storage tanks. Double wall, double integrity storage tanks are often used for storing cryogenic liquids. In an incident mentioned by osha.gov, An employee was blowing insulation into the annular space of a newly constructed liquefied natural gas tank. He apparently accidentally fell into the space, which was full of perlite. He was engulfed by the perlite and was asphyxiated. Perlite is an insulation material. When a job hazard analysis is carried out, do you consider asphyxiation hazards due to insulation, in double wall tanks?