RISK BASED PSM PROCESS SAFETY MANAGEMENT INDIA CONSULTANT INCIDENT INVESTIGATION HAZOP TRAINING ROOT CAUSE ANALYSIS AND LESSONS FROM INCIDENTS
Pages
December 27, 2022
December 22, 2022
Anhydrous Ammonia Hose Failure
December 20, 2022
Why Visakhapatnam gas leak should set off alarm bells May 9, 2020
December 16, 2022
December 12, 2022
December 8, 2022
December 2, 2022
ANOTHER ANNIVERSARY OF BHOPAL - LET ALL LISTEN TO THIS PODCAST
38 years have gone by and the victims are forgotten! India is waking up to the importance of preventing a Bhopal like incident after the LG Polymer incident in 2020. The root causes of that incident were similar to that of the Bhopal disaster.
Let all your senior leadership and all employees listen to this podcast by the BBC. There were enough warning before the incident happened.
https://www.bbc.co.uk/sounds/play/m001bs5c
Have a Process Safety Week in your organization and sensitize your leadership your workforce on the lessons of Bhopal.
TTHE LESSONS MUST NOT BE FORGOTTEN.
December 1, 2022
LINE BREAKING INCIDENT
On November 28, 1999, a blockage occurred somewhere in the recycle waste line on the second level. This line brings crude Teal with excess aluminum to T-103, which feeds back to the reactors. During the night shift they were able to blow the line from T-105 to the control valve, which left the blockage within about 20 feet of T-103. The morning of November 29, 1999, Employee #1, the outside operator, tried to blow out the plug through a detail (bleeder) just above T-103 with 150 pounds of nitrogen.
The nitrogen pressure went around the control valve via a by-pass to the slop tank. He closed the valves back toward the slop tank. Then he opened the valve into T-103 to try and blow nitrogen into the tank, but it was still plugged somewhere, which was about 1 to 2 feet of line. At this point they were going to have to perform a line break and separate the line above the valve on T-103. The line breaking permit was obtained. Employee #1 relieved the nitrogen pressure back to the slop tank, but the slop usually had 3 to 10 psig on it. He ensured that the valves were closed, locked and tagged.
Then the maintenance crew came to perform the line break. The crew consisted of four employees, which all wore a hard hat with attached face shield, safety shoes, safety glasses, PVC gloves, nomex, and aluminized suits. Employee #1 stayed in the area, but over at the guard rail. The guard rail was just under 10 feet and was about 9.5 feet from the line break. He wore the same PPE except the face shield and aluminized suit. The maintenance crew proceeded to break the flange. One bolt was out and the other three were loose. The shift supervisor was standing on the ground level talking with the Employee #1. Employee #1 told him the flange started to drip. It started to spray lightly and then quickly just gave way into a stream. The stream hit Employee #2 in the face, because he was kneeling as he was working. Employee #1 saw the flames. As he was being burned by the fire, he jumped over the guard rail and fell approximately 12 feet to the ground. Employee #1 sustained a fractured ankle and compressed L1 vertebrate, and was killed. The flash fire lasted about 10 seconds according to the shift supervisor. Employee #2 was hospitalized for his burns. Three other employees were burned during the accident but didn't require hospitalization.
Source:OSHA.GOV
November 27, 2022
CONFINED SPACE ENTRY INCIDENTS - USCG
This incident again reminds us of the dangers of confined space entry.
"Last Fall a foreign flagged containership during a coastwise voyage reported upon leaving port that
the vessel’s second engineer was missing. Despite an extensive search by the vessel’s crew and
officers, the individual was presumed to have gone ashore and missed the sailing. Upon arrival at
the following port the individual was found deceased behind an access door to the main propulsion
engine’s scavenging air receiver:
Read how the fatality occurred in this link:
https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/0204.pdf
November 23, 2022
Safety Alert High Velocity Vent Valves, Vacuum Valves, P/V Valves USCG Alert
"A recent marine casualty resulted in significant damage to tank structures, piping and components of
a combination chemical / oil product carrier. Vessel-to-vessel loading operations were taking place at
anchorage and one tank became over-pressurized. Subsequently, three cargo tanks and three
ballast tanks on the ship suffered catastrophic structural failures that allowed hazardous cargo to
migrate throughout those areas. This incident caused the vessel to list and created a very dangerous
explosion hazard requiring costly and time-consuming lightering and repair operations. Additionally, it
presented a hazard to the port and persons involved.
The investigation is nearly complete and investigators have identified several causal factors, one being the failure of the high velocity vent valve which did not open and prevent over pressurization of the tank while it was being filled".
Read the safety alert to understand why the high velocity vent valve failed to operate, in this link:
https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/0411.pdf
November 20, 2022
November 19, 2022
IT’S THE SEEMINGLY MINOR ITEMS that sometimes can create a catastrophe. USCG Safety alert
"This is a reminder to owner operators that sometimes it is the most seemingly minor thing such as a
mechanical part or electrical component that can lead to a catastrophe. For example, a nearly 20 year
old bulker was leaving port when its main engine throttle failed. In this case the vessel was able to
drop anchor without incident. The failure occurred because a small drive belt that connected the console throttle lever components to an electrical potentiometer failed. Movement of the throttle causes the
potentiometer to move and creates a variable signal to other controls which manage engine
speed. When the belt failed the control from the engine room console was lost"
Read this safety alert in detail with additional incidents mentioned in this link
https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/ll0114.pdf
November 15, 2022
Overeating Can Create Dangerous Gas! (Especially with Anaerobic Bacteria) USCG safety alert
This safety alert is very much applicable to us in the CPI. Anaerobic bacteria reside in ETP's.
This safety alert shares important information related to a unique, not very well known and potentially
deadly hazard that recently developed on a vessel involving the formation of dangerous levels of
Hydrogen Sulfide (H2S)1 gas within a waste oil tank. This was determined to be due to the use of
biodegradable cleaners and the chemical reactions and resultant H2S byproduct involved in breaking
down oils in an anaerobic (low oxygen) environment like that found in a full slop tank. In this case,
vessel officers had detected significant H2S concentrations (>200 PPM) in the vessel’s engine room
bilge holding tank.The cleaner provided micro-nutrients to the waste water thus causing the bacteria to thrive resulting in increased rates of H2S production.
Read the safety alert with detailed incidents in this link https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/0818.pdf?ver=2018-06-08-143912-267
November 11, 2022
Danger! Improper Bonding During Gas Freeing Can Have Explosive Results! USCG Safety Alert
"During gas freeing operations, cargo tank manway and butterworth openings are opened and the flammable vapors within the cargo tank are then removed using mechanical air moving equipment. As outside air is introduced into the cargo tank, the vapor/air mixture within the tank, and near the tank openings, will fall into the flammable range. During this time, if the air moving equipment used to gas free the cargo tank is not the proper type, is not properly maintained, or is not properly electrically bonded and secured to the vessel’s structure, static electricity generated by the air moving equipment can discharge as an electric arc and ignite the flammable vapor/air mixture".
Read the full safety alert with photos in this link https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/0120.pdf?ver=2020-01-30-101338-710
November 7, 2022
TANK SAMPLING DANGERS / H 2 S Threshold Limit Change USCG Safety alert
"Prior to using portable gas monitoring equipment, personnel should familiarize themselves with
ISGOTT Section 11.8 and safe work practices for conducting or witnessing these tests. ISGOTT
recommends when sampling tanks personnel should stand perpendicular to the wind to avoid being
downwind or upwind and creating eddies".
Read the safety alert in this link https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/0214.pdf
November 3, 2022
Electrical Issues Spark Major Concern – Addressing Hazardous Area Electrical Installations Knowledge Gaps
"The purpose of this Safety Alert is to emphasize the importance of properly installed and maintained
listed or certified safe electrical equipment in hazardous areas in order to reduce the risk of fire or
explosion onboard vessels. The Coast Guard has seen a number of instances where there was a lack
of knowledge in the marine industry as it relates to the installation, training,
maintenance and inspection of these certified systems"
Read the alert in this link https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/USCGSA_0520.pdf?ver=2020-07-06-132441-980
October 30, 2022
Failure of pipeline emergency shut-down valve - HSE UK
This alert is issued following the failure of a spring return pipeline emergency shut down valve (ESDV). The failure left the primary platform isolation device inoperable with the valve failed in the open position. Other ESDVs have been examined and have found to be at risk of failing in this manner. Spring return valves other than ESDVs are equally vulnerable.
Read the full report in https://www.hse.gov.uk/safetybulletins/pipelinevalve.htm
October 26, 2022
Chloride induced stress corrosion cracking of stainless steel thermowells: Potential for ingress of atmospheric moisture HSE UK
"This safety notice describes a specific degradation mechanism found inside stainless steel thermowells operating where the external atmosphere contains halides, as is typical in coastal locations or near to cooling towers. Thermowells can 'breathe' during normal operation as vessels heat up and cool down, drawing in the external atmosphere through non gas tight fittings. If the atmosphere contains halides this can leave any stainless steel susceptible to Chloride Stress Corrosion Cracking (CISCC). The HSL Research Report 902 (Reference 1) covers the susceptibility of stainless steel to CISCC in some detail and links to other research papers and published documents".
Read the full safety alert in this link https://www.hse.gov.uk/safetybulletins/thermowell-corrosion.htm
October 22, 2022
Catastrophic rupture of dead-leg pipe-work -HSE UK
"A recent failure on a UK refinery involved an 8" diameter vertical relief line, approximately 5m in length, which catastrophically failed during normal operation part way along its length, releasing approximately 75 tonnes of extremely flammable material at elevated temperature and pressure. Connected to an insulated process header and vessels, the failure involved complete separation of the relief line (which was not insulated).
Subsequent examination of the line revealed excessive internal thinning which was very local to the failure point, but relatively normal wall thickness elsewhere along its length. The inspection regime included regular thickness testing at four locations, but not at the area local to the failure. Notably, an adjacent relief line was also found to have very similar localised and severe internal corrosion, which had also gone undetected".
Read the full incident in this link https://www.hse.gov.uk/safetybulletins/catastrophic-rupture-dead-leg-pipe-work.htm
October 18, 2022
Failure of a road tanker pressure/vacuum relief valve
"This safety alert is aimed at haulage contractors, users of tank containers and road tankers, companies servicing pressure/ vacuum relief valves and authorised inspection bodies contracted to verify the functioning of these valves.
Tank containers and road tankers used for flammable, corrosive and toxic liquids and gases will normally have a valve fitted to prevent damage to the tank from changes in the internal pressure. Haulage containers used for less hazardous liquids and gases may also have a valve.
Following a road incident in April 2020, investigations by Cleveland Police and HSE found evidence that a pressure/vacuum relief valve, originally manufactured by Fort Vale Engineering Ltd, had been modified by a third party. The valve cap had a nut welded to the top, most likely to allow it to be serviced without the use of a special tool to remove the valve cap. The unauthorised modification prevented the valve’s safe operation"
Read the full report here https://www.hse.gov.uk/safetybulletins/failure-road-tanker-pressure.htm
October 14, 2022
Catastrophic failure of marine loading arm
The 8-inch nominal bore, hydraulically operated MLA involved in the incident had been in service for 11 years and had been regularly maintained by various recognised industry contractors. It had a rigid link pantograph balancing system with independent primary and secondary counterweights linked to the inboard and outboard arms. The MLA failed as it was being manoeuvred towards a ship manifold for connection. A section of the MLA fell backwards onto a jetty handrail narrowly avoiding live plant and pipework on an upper-tier COMAH establishment.
Source: https://www.hse.gov.uk/safetybulletins/marine-loading-arm-failure.htm
October 10, 2022
Stored Energy: Injury Caused by Failure of Expansion Joint in Fire-Fighting Equipment
Stored Energy: Injury Caused by Failure of Expansion Joint in Fire-Fighting Equipment
What happened?
During a trial of fire-fighting equipment, a hose expansion joint or bellows failed. The release of pressurized water hit a crewman who was standing nearby, slamming him backward and knocking him
unconscious. The fire pump was shut down and help was sought. CPR was administered; subsequently the injured person was medevaced. This incident was considered by our member to be a potential fatality. The injured person was in hospital for some weeks.
What went wrong? What were the causes?
Some identified issues were:
- There was inadequate management of significant risk;
- There was no understanding of the life time of the expansion joint or bellows;
- There was no installation procedure provided for this bellows by the manufacturer;
- There was no preventive maintenance or inspection/testing of the failed equipment.
What actions were taken? What lessons were learned?
- There had been a similar rupture of a bellows some years previously; this earlier incident was not investigated.
- Had it been investigated, it might have helped in preventing reoccurrence;
- Engineering and design of critical equipment during new building should take into consideration personnel safety as well as equipment protection;
- There needs to be a better design review of pressurized equipment, particularly where different components are in use.
October 6, 2022
Managing the risk of the Internet of Things - Control Engineering
"Nearly two decades ago, a disgruntled former employee used network access to remotely release sewage.
In 2007, researchers demonstrated that a generator could be destroyed by remotely opening and closing circuit breakers rapidly.
In 2014, hackers broke into the industrial network of a German steel mill and prevented a blast furnace from shutting down.
With respect to the more modern IoT devices, a researcher hacked his insulin pump, others managed to compromise smart meters, and, in a segment aired on "60 Minutes," Defense Advanced Research Projects Agency (DARPA) scientists remotely controlled automobile brakes"
Read the article
https://www.controleng.com/articles/managing-the-risk-of-the-internet-of-things/
.
October 3, 2022
Industrial Internet of Things in safety applications
Fast Forward As more wireless and Web-based applications boost IIoT adoption, some functions have moved into safety areas.The wireless diagnostic devices and applications available now covers a huge range and continues to grow.The same techniques used to monitor equipment condition can also be used to monitor safety devices and systems protecting the plant.
https://www.isa.org/intech-home/2018/march-april/features/iiot-in-safety-applications
September 28, 2022
Liquid nitrogen explosion
https://www.safework.nsw.gov.au/__data/assets/pdf_file/0008/1054718/liquid-nitrogen-explosion.pdf
September 24, 2022
Nitrogen pipeline ruptured
Part of the pipeline network used to channel nitrogen gas at a manufacturing plant has suffered a failure and ruptured. This incident took place after the refilling of liquid nitrogen from transportation vehicle into the storage tank was done. No loss of life or injury was reported because there was no worker in that area during accident.
Investigation found (revealed) that the pipelines which are made of carbon steel, ruptured in many parts during the accident. Failures on welded part of the pipeline were also detected.
Recommendation of Improvement:
- Welding on critical and pressurised parts should be done by a qualified welder. The process and method of welding shall meet the requirements of relevant standards.
- Design of storage tanks and pipelines should be in compliance with the appropriate design standards and code of practice.
- Pressure safety valve shall be installed at appropriate location on the storage tanks to prevent undetected overpressure. The safety valve must also be suitable with the range of pressure used.
- Some metals become brittle when exposed to low temperature. This condition can cause failure to happen in a short period of time and without imminent warning. For this purpose, any metal used for pipelines and storage tank shall be suited to the type of gas/ liquid and operating temperature/ pressure, especially if it involves cryogenic process or materials.
Source: https://www.dosh.gov.my/index.php/osh-info-2/safety-alert/749-nitrogen-pipeline-ruptured
September 20, 2022
Rupture of a Liquid Nitrogen Storage Tank
On 28th August 1992, there was a catastrophic failure of a storage tank containing liquefied nitrogen. The failure resulted in the collapse of almost half of the manufacturing site and damage to houses and vehicles within a 400 metre radius. Fragments of the vessel were projected up to 350 metres, the largest of which, a section of the outer shell head was 1.5 metres wide and 8mm thick.
The tank was a double-walled vacuum-insulated ultra-low temperature storage vessel designed to operate at -196°C and 9.3 bar (maximum normal operating pressure).
The inner vessel broke into seven fragments and the outer vessel broke into eleven main fragments and numerous smaller pieces. It was discovered during the course of the investigation that most of the valves on the system were closed including the top liquid inlet, liquid outlet and the isolation valves for the relief valve and bursting disc. The vessel was therefore under completely closed conditions at the time of the accident. The bursting disc was found to be ruptured despite the closed inlet valve, however it was believed that the valve might have been closed after the disc ruptured on a previous occasion. The inner and outer shells ruptured as a result of excessive pressure under closed conditions. It was estimated that the inner shell ruptured at a pressure of 68.7 bar. The pressure reached this level as a result of heat inflow over the sixty days between its final filling and the time of the explosion.
Failures in technical measures
- Isolation valves were fitted below both relief devices without any interlocking system to ensure that one device was always protecting the vessel.
- Relief Systems / Vent Systems: relief valves, bursting discs
- There were no manuals for the operation of the nitrogen vessel. The daily inspections required on the vessel were largely neglected and no safety instructions were given to employees.
- Training: operator training
- Operating Procedures: provision of comprehensive operating procedures
Source: https://www.hse.gov.uk/comah/sragtech/caseliqnitro92.htm
September 16, 2022
Liquid nitrogen incident
At 5:30 p.m. on February 5, 2017, an employee was responding to an emergency alarm. As he entered a space that was oxygen deficient, he was knocked unconscious. The employee was rescued from the space and was hospitalized, where he received treatment for having been exposed to an oxygen deficient atmosphere, as well as hypothermia and frostbite. His injuries resulted in amputation of an unspecified extremities. The incident investigation revealed that the space contained liquid nitrogen.
Source:Osha.gov
September 12, 2022
Electrocution incident
On January 14, 2004, Employee #1, was contracted by the client to provide additional electrical power to boost up the power available from the utility company, which the client needed to test some special equipment. This client is involved in the manufacture and testing of cryogenic pumps and other parts used in the aerospace industry. The manufacturing and testing operations are housed in a large building. The employer had temporarily wired up additional generators to a transformer owned and maintained by the client. This temporary wiring setup including the generators and the transformer was entirely located outside in the parking area behind the manufacturing building. This testing had been completed and the employer was in the process of dismantling this temporary setup when this incident occurred. The circuits containing generators and the transformer had been completely shut down and there was no live part in the temporary wiring setup. The enclosure that housed this transformer for the temporary setup had three additional cables running through it. These cables were spliced inside this enclosure and had no connection to the transformer. These spliced cables carried Edison 4160VAC power for a 150-horse power motor used by the client as permanent equipment, which was not involved in the temporary wiring setup by the employer. It appears that the transformer enclosure was also used as a junction box for the spliced cables. Each of the spliced connections was covered with pieces of PVC pipe and some duct tape. Before the incident a coworker had tested transformer terminals and determined that there was no power in any part of the transformer. As part of the temporary setup dismantling process, Employee #1 was helping the corker to disconnect the cables from the transformer. While Employee #1 was disconnecting a cable from the transformer, one of the spliced connections was exposed, which started an electrical arc and fire. The right forearm of Employee #1 was burned in the fire before he could get away. Employee #1 suffered third degree burns to his right forearm and was hospitalized for three weeks.
Source:Osha.gov
September 8, 2022
Asphxiation incident
Employees were tasked to fill a series of Chart MVE 1842P-150 Cryogenic Freezers in an enclosed storage room on a weekly basis. The room was not equipped with an adequate engineered ventilation system or oxygen monitoring equipment or system. On the evening of November 20, 2019, an employee began topping the bulk tanks off with liquid nitrogen when the room became filled with nitrogen gas causing the employee to collapse and eventually succumb to the oxygen-deficient atmosphere created in the room. The room was not equipped with an adequate engineered ventilation system or oxygen monitoring equipment or system. This condition exposed an employee to an oxygen deficient atmosphere while filling bulk tanks with liquid nitrogen.
Source:OSHA.gov
September 4, 2022
Decomposition incident
On September 21, 2003, Employee #1 and several coworkers were working at a chemical plant that deals with nitric oxide. On the day of the accident, a major leak occurred in a stainless steel distillation column. The nitric oxide leaked into the facilities surrounding vacuum jacket and into the atmosphere through a pump, which controls a high quality vacuum inside the jacket to minimize transmission of heat toward the cryogenic distillation columns. A brown cloud quickly formed and the temperature and the pressure inside the distillation column and its surrounding vacuum jacket began to rise. The leak was detected and the vacuum pump was turned off to halt the leakage of nitric oxide into the atmosphere, allowing the pressure inside the column and vacuum jacket to stabilize around 130 psi. Although stabilized, the pressure was far above the normal pressure of less than or equal to atmospheric pressure (14.7 psi). Approximately 3 hours later, an explosion occurred. The operation and process were destroyed, and debris flew through the plant. Employee #1 suffered lacerations due to flying glass and was treated at a local hospital, where he received stitches and then released. A detailed investigation determined that the cause of the explosion was most likely due to something inside the vacuum jacket initiated the dissociation of nitric oxide, a reaction that is very rapid, exothermic, and self-propagating once started.
Source:Ohsa.gov
August 31, 2022
HAS YOUR HAZOP STUDIED THIS POSSIBILITY?
On April 2, 2003, Employee #1 and a coworker, the technicians, were watching a polymerization process involving styrene and acrylonitrile monomers. Employee #1 and the coworker's jobs involved monitoring a reactor vessel throughout the process. At the end of the batch process, non-polymerized monomer and vapors were stripped from the reactor through a condenser system to a distillate collection tank and were ultimately charged to subsequent batches. Toward the end of the stripping process, Employee #1 left the control room to determine if enough distillate had been removed to allow the remaining water and mixture to be dumped to the "dirty" sewer and a collection system. While Employee #1 was in the vicinity of the reactor, an explosion occurred in a small auxiliary charge tank. A piece of metal struck Employee #1's abdomen and killed him. Although the charge tank was not in use at the time of the accident, a small amount of the batch had back-flowed through a valve between the reactor and the auxiliary tank during the reactive process. The batch continued to react in the auxiliary tank, overheating and overpressurizing the tank.
Source:Osha.gov
August 27, 2022
WHERE DO YOUR RUPTURE DISCS VENT?
Employee #4 was cleaning the #6 chemical reactor on July 19, 1990, with a flammable mixture of solvents when the reactor burst its rupture disc and the mixture was expelled into the plant. The solvent ignited and the vapor cloud explosion resulted in the plant's 43 employees being injured by flying debris and/or being thrown by the force of the explosion. Employee #4 eventually died from his burns. Employee #1, a maintenance employee, was moving away from the area when he was struck in the head and killed by debris flung during the explosion.
Employees #3, #6, #7, #8, #9, #16, and #19 were located in the manufacturing offices in Building 4, about 75 ft south of the reactor. Employees #2, #10, #11, #12, #14, #15, and #17 all worked in Building G, 50 to 75 ft southwest of the reactor and were leaving when the explosion either threw debris at them or threw their bodies onto equipment or debris. Employee #5 was in the same building as the reactor and was thrown down by the explosion, sustaining burns and crushing injuries. Employee #13 sprained his knee while moving from the break room to the courtyard, about 100 ft southeast of the reactor. Employee #18 suffered a sprained left thigh and a bruised shoulder.
It appeared that the reactor was not vented to a safe location and had primitive temperature controls, and the company did not enforce the mandatory attendance of operators at the reactors during operation. All of these factors, including minimal operating procedures (none specifically for cleaning), led to the explosion and the resulting extensive injuries and property damage.
Source:Osha.gov
August 23, 2022
Electrical Protection of 3 phase Motors: Types and Protection Schemes
August 20, 2022
Process Control Basics
August 16, 2022
CAMPAIGN AGAINST ASPHYXIATION
https://www.linde-gas.com/en/images/Campaign%20against%20asphyxiation_tcm17-13907.pdf
Share this newsletter with all your employees and contractors. It may save a life.
August 12, 2022
COLD BURN INCIDENT
On Tuesday 17th May, a worker received serious cryogenic burns after immersing their hands in a container of liquid nitrogen whilst trying to shrink a brass bush for inserting into an excavator boom arm.
How did it happen?
The worker was not wearing the correct personal protective equipment for the task. Further details related to the incident are not available at this time
Key issues
Liquid Nitrogen
Liquid nitrogen is one of the cryogenic liquids commonly used in the mining industry. As “cryogenic” means related to very low temperature, it is an extremely cold material. Liquid nitrogen has a boiling point of negative – 195.8 degrees centigrade and can expand to a very large volume of gas.
The vapor of liquid nitrogen can rapidly freeze skin tissue and eye fluid, resulting in cold burns, frostbite, and permanent hand and eye damage, even by brief exposure.
Liquid nitrogen expands 695 times in volume when it vaporises and has no warning properties such as odour or colour. Hence, if sufficient liquid nitrogen is vaporised to reduce the oxygen percentage to below 19.5%, there is a risk of oxygen deficiency which may cause unconsciousness. Death may result if oxygen deficiency is extreme. To prevent asphyxiation hazards, handlers must make sure that the work area is well ventilated.
Without adequate venting or pressure-relief devices on the containers, enormous pressures can build upon evaporation. Users must make sure that liquid nitrogen is never contained in a closed system. Use a pressure relief vessel or a venting lid to protect against pressure build-up.
Handling Safety Practices
Liquid nitrogen should be handled in well-ventilated areas.
Handle the liquid slowly to minimize boiling and splashing.
Use tongs to withdraw objects immersed in liquid nitrogen - Boiling and splashing always occur when charging or filling a warm container with liquid nitrogen or when inserting objects into the liquid.
Use only approved containers. Impact resistant containers that can withstand the extremely low temperatures should be used. Materials such as carbon steel, plastic and rubber become brittle at these temperatures.
Only store liquid nitrogen in containers with loose fitting lids (Never seal liquid nitrogen in a container). A tightly sealed container will build up pressure as the liquid boils and may explode after a short time.
Never touch non-insulated vessels containing liquid nitrogen. Flesh will stick to extremely cold materials. Even non-metallic materials are dangerous to touch at low temperatures.
Never tamper or modify safety devices such as the cylinder valve or regulator of the tank.
Liquid nitrogen should only be stored in well-ventilated areas (do not store in a confined space).
Do not store liquid nitrogen for long periods in an uncovered container.
Cylinders should not be filled to more than 80% of capacity, since expansion of gases during warming may cause excessive pressure build-up.
Eye / Face ProtectionSuitably rated full face shield over safety glasses or chemical splash goggles are recommended during transfer and handling of liquid nitrogen to minimise injuries associated with splash or explosion.
Skin Protection
Suitably rated, loose-fitting thermal insulated or leather gloves, aprons, long sleeve shirts, and trousers without cuffs should be worn while handling liquid nitrogen. Safety shoes are also recommended while handling containers. Gloves should be loose-fitting, so they are able to be quickly removed if liquid nitrogen is spilled on them. Insulated gloves are not made to permit the hands to be put into liquid nitrogen. They typically only provide short-term protection from accidental contact with the liquid.
Source: https://www.rshq.qld.gov.au/safety-notices/mines/use-of-liquid-nitrogen-in-the-mining-industry
August 8, 2022
NITROGEN ASPHYXIATION INCIDENT
At approximately 2 a.m. on August 8, 2001, Employee #1 was working on top of a reactor under nitrogen purge. A coworker was wearing breathing air with a communication device. The lead man was on top of the reactor overseeing the job. The lead man turned around and began communicating on the headset with the workers monitoring the breathing air. Employee #1 walked past the lead man and the coworker without breathing air and reached into a manhole. Employee #1 was overcome by the fumes/vapors and fell 3 to 4 feet into the reactor. The coworker and lead man pulled Employee #1 out of the reactor, and the lead man performed CPR until the rescue team arrived. Employee #1 was pronounced dead at the hospital. Employee #1 died from asphyxiation.
Source:Osha.gov
August 4, 2022
PIGGING INCIDENT
At approximately 8:00 a.m. on June 25, 2012, an employee was at the side of the pig launcher. The process was to purge the line of carbon gas with nitrogen. The nitrogen was pumped by a rig used to frac wells. The pump truck was capable of creating pressures which were several times greater than the launcher was designed and built for.
The employee had several responsibilities some of which were to check the joints of black pipe feeding the nitrogen. This entailed pouring soap water on the joints and check for bubbles. He was also responsible for watching the pressure gauges on the launcher, getting the line purged so the pigging operation could start, and opening and closing the ball valves in the line t o provide for proper flow. He had just spoken to another employee while looking at the gauges on the launcher when the launcher ruptured. The ball valve leading to the 16-in. main line was not open. The pump truck had been pushing nitrogen into the small pig launcher instead of over three mile long pipeline. The gauges were not reading any pressure at all and when the pump truck kicked up the pressure, the launcher ruptured. The launcher was shot over 800 feet away.
The main part of the vessel struck another employee killing him instantly.
Source:Osha.gov
July 31, 2022
EVEN A SMALL AMOUNT OF WATER CAN KILL
Employee #1 and a helper entered a lift station to unclog the system. Employee #1 called out to the helper that he was having trouble breathing and needed help exiting the lift station. The helper inserted the
ladder into the lift station and attempted to help Employee #1 climb up but could not hold on to him because his hand was slippery. Employee #1 slumped into the bottom of the lift station and his mouth and nose were partially submerged in the water. He was transported by emergency services to the hospital where he died of respiratory failure resulting from sewage water in his lungs
July 27, 2022
Emergency Isolation for Hazardous Material Fluid Transfer Systems – Applications and Limitations of Excess Flow Valve
https://archive.epa.gov/emergencies/docs/chem/web/pdf/efv_alert.pdf
July 23, 2022
ARE YOU IDENTIFYING ALL SOURCES OF ENERGY FOR LOTOTO?
The fans were shut down, tagged-out, and locked-out. The employee proceeded to remove the enclosure metal guard to expose the belt and pulley drive for the inspection. Although the fan was tagged and locked- out, it was not blocked-out. The exhaust fans in a room below were not stopped. Their operation created an airflow which traveled through the same duct system as for the supply fans upstairs. The air flow through the duct caused the supply fan blades to spin freely. The fan blades were not blocked before servicing. At approximately 8:30 a.m., when the employee was removing the enclosure guard for the V-belt and pulley drive of the spinning fan, the in-running nip point amputated his left middle finger. He
screamed as Coworker #1 came to his aid. He was taken to XXX Hospital by Coworker #1. He was treated and released the same day.
July 19, 2022
3 Employees Killed, 2 Injured By Hydrogen Sulfide Exposure
Employee #1 was inside a frac tank shoveling residue (called BS) to one end of the tank for subsequent vacuuming and removal. As he completed the task, the tank was washed down with waste water containing hydrogen sulfide. Approximately 8 minutes following the waste water entrance, Employee #1 collapsed from exposure to the chemical. Employee #2 entered the tank and attempted to rescue Employee #1, but he too collapsed. Apparently Employees #3 and #4 entered the tank and attempted a rescue and but succumbed also. Employee #5 attempted to revive Employee #1 through an opening at the end of the frac tank. He was affected by the hydrogen sulfide gas but was able to call the city's first responders. Employees #1, #3, and #4 died of hydrogen sulfide exposure. Employees #2 and #5 were hospitalized.
Source:Osha.gov
July 15, 2022
EXPLOSION IN SALT WATER TANK
At approximately 2:30 a.m. on July 30, 2011, Employee #1 was working the night shift at a saltwater disposal facility. Specifically, the facility specializes in the disposal of salt water that is contaminated with field oil waste. The water would usually be separated from the oil and petroleum based materials in a settling tank. The water would then pumped back into the ground through an injection well, while the oil based material is gravity drained into a series of collection tanks. The oil would then sold to oil recyclers. During Employee #1's shift, he was monitoring two oil collection tanks that were connected to a separation drum tank.
The first of the two tanks was also connected to the second tank to allow for spillover as the amount of liquid rose. Under normal operation, the tanks would take several days to become full; however, facility operators would frequent the catwalk area that was accessed by way of a ladder to gauge the tanks levels. After receiving a water delivery from a full tanker-truck, Employee #1 accessed the catwalk to gauge the water level. Soon after reaching the tank area, an explosion occurred. The truck driver, who was leaving the facility, observed the explosion and following fireball in his rear view mirror. The driver immediately stopped his truck and contacted emergency services. Despite the fire spreading to both tanks, Employee #1 was able to escape the fire crazed area; however, his clothes were completely burned off and over ninety percent of his body was burned. Employee #1 collapsed on the front porch area of the facility office, where emergency personnel, a short time later, began treatment. Employee #1 was taken by helicopter to Ardmore Hospital, where he died. The accident investigation revealed that Employee #1 had a history of smoking near the storage tanks and had been warned by the employer to stop several times.
Source:Osha.gov
July 11, 2022
"Sewage systems on vessels are known as Marine Sanitation Devices (MSDs) or Collection, Holding and Transfer Tanks (CHTs). Cleaning these systems is required for operations such as routine surveys and surface preservation, equipment modification, repairs and maintenance. Entering and cleaning
sewage tanks, piping and components present specific hazards to workers that put them at risk for injuries and illnesses if they are not properly protected (29 CFR 1915.13).
Workers are often exposed to dangerous atmospheres during tank opening and venting; manual pumping and stripping; breaking or dismantling components and piping; and pressure
washing, mucking, and scaling (29 CFR 1915.11(b); 1915.12). A dangerous atmosphere may expose workers to the risk of death, incapacitation, injury, chronic or acute illness, or impaired ability
to escape unaided from a confined or enclosed space (29 CFR 1915.11(b)). When working on CHTs/MSDs, special attention should be given to good hygiene practices, proper use of personal
protective equipment and safe confined space entry procedures (29 CFR 1915.88; 1915 Subparts B & I).
The information in this document can help prevent exposing workers to the known and unknown dangers of handling treated or untreated sewage and gray water tanks during tank opening, entry,
cleaning and related operations. Related components/operations include: piping, aeration, vacuuming, settling, and treatment tanks and apparatus; sewage-contaminated water tanks or waste oil
tanks, bilges, or sumps; and valves, pumps, grinders, macerators and other contaminated equipment".
https://www.osha.gov/sites/default/files/publications/OSHA_FS_3587.pdf
Source:Osha.gov
July 7, 2022
CHLORINE EXPOSURE INCIDENT
On April 2, 2002, Employee #1 and a coworker, employees of a water treatment plant as waste water treatment operators, were changing out five 1-Ton cylinders, located in a chlorine cylinder room. Employee #1 attempted to disconnect the yoke number two of the five 1-Ton cylinders, but a high pressure leak of chlorine gas escaped from the cylinder into his breathing zone. Employee #1 was able to immediately tighten the yoke connection, stopping the leak, but required the coworker to finish the task. With Employee #1 sitting to the side, the coworker, after a couple of attempts, was able to disconnect the yoke connection without any further chlorine gas escaping. After notifying management of the incident, the coworker drove Employee #1 to Hospital Emergency Room. Once admitted, Employee #1 was treated for chlorine gas exposure and diagnosed with bilateral lower lobe pneumonia.
July 3, 2022
A 42-year-old laborer leak testing joints inside a 54-inch round pipe suffered fatal blunt force injuries in October 2015, when an inflatable ¿bladder¿ ruptured at a waste-water treatment plant. Inspectors from the U.S. Department of Labor¿s Occupational Safety and Health Administration found his employer failed to train him properly on the testing procedure.
Workers can be killed when employers fail to protect construction workers from the many dangers in confined spaces, said Assistant Secretary of Labor for Occupational Safety and Health Dr. David Michaels. These are among the first citations under OSH¿s new Confined Space Standard. Employers can prevent more tragedies like this one if they ensure proper training of workers and communication among multiple employers whose workers are on the same site.
In August 2015, OSHA implemented its confined space in construction standard after research showed proper safety procedures would protect hundreds of workers each year from life-threatening hazards. Hazards include the risks of toxic exposure, electrocution, explosion and asphyxiation present for workers in confined spaces such as pipes, manholes, crawl spaces and tanks. In an emergency, it can be difficult to exit these spaces quickly or for rescuers to enter safely.
The agencys investigation also found the four companies failed to continuously monitor confined spaces for atmospheric and other hazards and train workers in hazards.
Source:Osha.gov
June 28, 2022
ARE YOU PERFORMING YOUR PSSR'S CORRECTLY?
A closure of an UV (shutoff valve) was provided in the design of the plant, to avoid two phase flow when carryover occurred. During an abnormality, the shutdown system activated the UV but the UV did not close. The RCA revealed that the UV did not close due to excessive friction caused by the presence of construction debris left behind that prevented the UV from closing
June 24, 2022
WASTE WATER TANK INCIDENT
On September 9, 2003, Employees #1 and #2 were extending the guardrail system to the hatch and platform area on top of a tank located on the Brewery property. The tank was used for the storage of solid waste at the waste water treatment facility. The tank was 40 ft in height and 48 ft in diameter. The employees were arc welding the guardrail system, 40 ft above the ground, when an explosion occurred. Employee #1 fell to the ground receiving fatal injuries. Employee #2 fell to the inside of the tank, an opening of approximately 10 ft left due to the explosion. The tank had to be drained in order to recover the body. Employee #2 apparently died from injuries due to the explosion
Credit:Osha.gov
June 20, 2022
ARE YOU INSPECTING YOUR PILOT OPERATED VALVES CORRECTLY?
A Pilot operated relief valve failed to lift during planned recertification in the workshop. The cause of failure to lift identified as a plug fitted in the pilot exhaust port. Plug was removed from pilot exhaust port and RV functioned as intended. On inspection of three remaining RV’s on compressor discharge, it was
found that another RV also had a plug fitted in the pilot exhaust port.
June 16, 2022
ARE YOU CONSIDERING HUMAN FACTORS DURING YOUR HAZARD IDENTIFICATION?
An ammonia leak occurred in the machinery room of an unoccupied arena. An employee was attempting to add oil to an ammonia compressor when he observed a leak (fill hose was not attached). Approximately 200 lbs ammonia was released.
Qualified person was trained, but with minimal experience in this procedure. No written procedure was available, and an error occurred while executing the procedure. The shut-off valve type (wrench-operated,
mufti-turn, no position indicator) added complexities to the process.
Source: British Columbia Safety Authority
June 12, 2022
WHY HAZOP STUDY IS IMPORTANT
Approximately 200 lbs ammonia was released to atmosphere. The condenser safety valve activated due to ‘no cooling’ in the condenser while the ammonia compressor was operating. While restarting the plant after a power failure, the operator forgot to start the condenser circulating pump (which should be started before starting the compressor). The compressor was started without condenser cooling, and as a result, ammonia gas temperature began to rise, thus raising the gas pressure in the system. Eventually the gas pressure rose more than the safety valve setting, activating the safety valve which released the
ammonia to atmosphere.
The compressor’s high pressure safety cut off did not activate. The high pressure cut off is supposed to activate and shut off the compressor unit when the system senses a high pressure condition.
Source: British Columbia Safety Authority
June 8, 2022
ARE YOU SPECIFYING PRESSURE GAUGES CORRECTLY?
Approximately 100lbs ammonia was released into an unoccupied processing room of an industrial facility when a pressure gauge failed on the liquid line to an ammonia evaporator. Inspection revealed that a second pressure gauge (on the hot gas line for the same installation) was pinned at maximum pressure. Both pressure gauges had a range of 0 to 150psi and were installed in a system with an operating pressure of 150 to 160psi. The pressure gauge failed from over-pressure operation.
Source: British Columbia Safety Authority
June 4, 2022
ARE YOU INPECTING SMALL BORE TUBING?
An ammonia leak occurred at a commercial-industrial facility. Approximately 10 lbs ammonia entrained in approximately 200 litres of compressor oil was released when a suction side 3/8-inch pressure sensing line failed. The suction side oil pressure pushed approximately 200 litres of oil from the reservoir onto the floor where the entrained ammonia then escaped to atmosphere. The 3/8-inch stainless steel tubing within the compression fitting failed when a circumferential crack completely fractured. The crack within the
3/8-inch stainless steel compression fitting did not show up on external inspection. Metal fatigue appeared to be a factor, along with unit vibration and initial metal stress within this type of compression joint.
The refrigeration contractor identified the main cause and factors leading to the failure as a severe vibration condition of the compressor. This severe vibration condition only occurs when only happens when the control slide valve is at, or at near its minimum position. The vibration was so intense that the contractor immediately shut the compressor down. Also, the contractor’s investigation discovered the ‘PHD’ vibration monitoring system was inactive. When the monitoring system was activated, the compressor in fact shut down on ‘high vibration.’
Source: British Columbia Safety Authority
May 31, 2022
ARE YOUR SAFETY DEVICES WORKING?
Ammonia was released at a recreational facility. A high pressure cut out switch failed to shut down a compressor when the compressor experienced a high pressure condition. Pressure continued to build until a safety relief device operated releasing ammonia gas to atmosphere via the relief stack,
which triggered the ammonia alarm.
The water supply line to the condenser had no protection and was subject to freezing during cold weather. The high limit switch was old (1986) and is mounted on the compressor base subjecting it to vibration. The safety relief operated as designed, venting gas to atmosphere, preventing a possible
catastrophic failure.
Source: British Columbia Safety Authority
May 27, 2022
SAFETY IN DESIGN OF PIPING
"A process engineer must complete the preliminary preparations of process flow diagrams, material and energy balances, piping and instrumentation diagrams (P&IDs), process control philosophy, and identification of the hazardous nature of raw materials, chemicals, byproducts and final products. Afterward, documents including process equipment layout drawings (plan and elevation) and unit plot plans are issued to engineers from other disciplines.
Involving engineers from different disciplines in the design phase provides unique perspectives that add value to basic documents, such as improved safety design features. Discipline engineers are required to consider design and safety requirements that are applicable for their specific domain as per local, national, international, industry-specific and company standards and regulations, and good engineering practices.
The role of a piping engineer during the design of piping systems is explored here, as well as how that piping engineer can—from the initial design phase—lower the risks that can arise from handling hazardous materials, contribute to reducing potential liability and help create a safer environment for the public".
READ THE FULL ARTICLE IN LINK
May 23, 2022
CONTROL HAZARDOUS ENERGY
https://www.aiche.org/ccps/control-hazardous-energy-lock-out-and-tag-out
"Lock-out and tag-out (LOTO) is a critical part of a strong all-around
safety program. In LOTO, maintenance employees work with production
employees to positively prevent all forms of hazardous energy from
causing harm. Hazardous energy comes in many forms. Electrical energy
can cause electrocution and burns, provide ignition to flammable
atmospheres, and activate mechanical equipment. Steam can cause burns or
initiate hazardous reactions. Nitrogen can cause asphyxiation. Chemical
flow can cause uncontrolled reaction and injury. When a piece of
equipment is being worked on, all sources of hazardous energy must be
securely and positively locked out until the equipment is
operational. Untold numbers of major process safety incidents and
individual injuries have been caused by failure of LOTO. A prime example
is the Bhopal catastrophe, one of the worst incidents ever to have
occurred, which was caused in part by the failure of LOTO. Recently, a
company process safety manager called CCPS asking for help in persuading
a newly acquired facility within his company to implement a LOTO
program. The manager was frustrated because, as the plant director
stated, “We understand completely that maintenance workers are
endangered if power or material flow were allowed to equipment they are
servicing. That’s why no one would ever activate a switch or valve
during a maintenance activity. LOTO is just extra, unnecessary
work.” The company process safety manager knew that with the plant
director’s attitude, the plant could be on the road to disaster. Could
CCPS help him make the case for LOTO? At CCPS, we firmly believe that it
is better to learn from the mistakes of others rather than to learn by
painful, personal experience. So we asked CCPS member companies to give
us examples of accidents caused by LOTO failures, and to provide
testimonials about the importance of LOTO. The purpose of this article
is to share this information with you, to help you lead the
implementation or improvement of LOTO in your
company. A brief overview of LOTO procedures and tools are provided, as are references to more detailed resources."
Reference: https://www.aiche.org/ccps/control-hazardous-energy-lock-out-and-tag-out
May 19, 2022
WHAT IS A BLEVE?
http://www.hrdp-idrm.in/e5783/e17327/e27015/e27750/
For a BLEVE situation following four conditions must be present:-
- There must be a substance in liquid form. Most of the destructive BELEV's that have occurred have involved flammable liquids and liquefied flammable gases. BLEVE can occur with any liquid, even water. The only difference is that with non¬flammable liquids there is no fireball. However, there will still be damaging effect including the propagating of creaks in the structure of the container together with possibility of subsequent failure and propulsion.
- The liquid must be in a container like sphere, bullet, and road/rail tanker.
- The contained liquid must be at a temperature above its normal boiling point at atmospheric pressure at the time container allows the pressure inside to build up above atmospheric pressure, the fluid, in the container is able to remain in the liquid state, even through its temperature is above its normal boiling point. This increase in pressure raises the Boiling point of the contained liquid above its boiling point.
- There must be a failure of the container in order to have BLEVE. This container failure can be due to following courses:
- Flame impingement.
- Internal structural weakness of the container
- Failure of improperly designed SRV
- Impact from a mechanical cause such a road accident, tanker derailment allowing flammable liquid to flow out.
May 15, 2022
May 10, 2022
SAFE ACCESSING OF PRESSURE VESSELS
"Operatives and technicians must frequently climb into pressure vessels in order to perform construction, maintenance, repair and inspection work. However, the access points through which they must pass for this purpose are often so small that although access is possible, rescuing these personnel in the event of an accident presents considerable difficulties. The Polytechnic University of Milan has conducted a number of studies into this issue in the course of two degree theses."
SEE THE LINK FOR FULL ARTICLE
May 6, 2022
NON METALLIC GASKETS - AVOIDING LEAKS AND BLOWOUTS
https://www.plantengineering.com/articles/nonmetallic-gaskets-avoiding-leaks-and-blow-outs/
"The compressive stress on a gasket plays a larger role in its ability to maintain pressure than its tensile strength.By Dave Burgess October 1, 1999
The compressive stress on a gasket plays a larger role in its ability to maintain pressure than its tensile strength. Why is this significant? It is the reason for many gasketed joint problems!
In a classic scenario, a joint is assembled without controlled bolt loads; that is, without known and controlled bolt torques. The joint withstands a hydro test at 1.5 or 2 times rated pressure, yet leaks or blows out after a period of service at pressures well below the test pressure.
Was this failure due to a loss of gasket tensile strength? Probably not. Gasket tensile strength alone cannot be counted on to hold system pressures. What very likely occurred was loss of compressive stress on the gasket."
READ THE COMPLETE ARTICLE IN THE LINK
May 2, 2022
ETHYLENE OXIDE RELEASE INCIDENT
https://dnrec.alpha.delaware.gov/croda-questions-answers/
"What happened at the Croda Atlas Point plant?
At 4:15 p.m., Sunday, November 25, 2018 ethylene oxide (EO) was accidentally released into the air from Croda’s ethylene oxide plant. Since EO is very soluble in water, Croda deployed its water deluge system to contain as much of the release as possible. Croda personnel also began transferring the EO from the leaking vessel in the processing equipment to a secure containment vessel. Local responders and DNREC Emergency Response arrived. Water suppression continued. With input from Croda personnel, responders determined that by opening two nitrogen valves in the processing equipment, the remaining EO from the leaking vessel could be transferred to the non-leaking vessel, stopping the release."
READ THE LINK FOR COMPLETE DETAILS...
April 29, 2022
SODIUM CYANIDE LEAK
Incident
A plant operator responded to a bund alarm and observed sodium cyanide solution overflowing from a storage tank. A pool of approximately 84 000 litres of solution had formed and was contained within the tank bund. The site emergency plan was enacted and an exclusion zone was established around the area whilst the product in the bund was transferred to another tank. The concrete bund contained the spill, and the recovered solution and all of the washings were kept for use in future blending operations.
Cause
The combination of a faulty valve and failure by an operator to follow standard operating procedure, led to the tank overfilling. The overflow spilt into the bunded area and activated the bund alarm.
Consequences
The defective valve was repaired and the tank high-level critical alarm system has been reviewed and improved. The tank overflow piping is also under review to identify options to prevent recurrence. The responsible operator has been counselled on appropriate self-check work systems. There were no injuries or damage to any property as a result of the incident and the emergency response plan functioned as intended.
Source: Department of Minerals and Energy, Australia
April 25, 2022
CHLORINE LEAK DUE TO STRESS CORROSION CRACKING OF SS BOLTS
Incident
Approximately 150 kg of chlorine gas was released over a period of 140 minutes, due to failure of bolts on a vacuum gas regulator attached to an on-line liquefied chlorine gas drum, used for water treatment. The incident occurred outside work hours, however plant operators were not called out, as the plant alarm system was not correctly programmed. Impact from the release to the surrounding community was limited to chlorine odour being detected by a passing motorist who reported the odour to the operator of the
site. The leak was isolated by a plant operator who arrived at the scene after the release was reported.
Cause
Inspection of the vacuum gas regulator revealed that the release was due to the failure of four bolts on the regulator. Material test results show that the failure of the stainless steel bolts was due to chloride-induced-stress cracking from chlorine attack, which is assumed to have resulted from an extremely small leak over a short duration.
Consequences
As part of the investigation, a number of changes to prevent recurrence of the event have been identified and implemented. These include introduction of a weekly leak check, the company committing to inspection of all vacuum regulators, the replacement of any inappropriate bolts and reprogramming of the chlorine alarm. In addition, the company will investigate the use of different alloy bolts.
Source: Department of Minerals and Energy, Australia
April 21, 2022
NITROGEN HOSE BURST AND RELEASED AMMONIA
Incident
A release of ammonia occurred from a chemical plant when a hose burst following maintenance to an ammonia filter. The release of ammonia was detected by operators due to ammonia alarms and a high flow of ammonia to the plant. The site emergency siren was activated to alert people of the incident and operators isolated the supply of ammonia to the plant. Operators donned personal protective equipment
and doused the leak with water in order to gain access to the area to isolate the leak.
Cause
Ammonia filters were used to remove contaminants from the liquid ammonia, prior to it being processed in the plant. An essential step in the maintenance of filters is a nitrogen purge of the system. After purging occurs, the filter is changed, resealed and the nitrogen hose disconnected. The relevant valves are then opened to recommission the system with ammonia. In this instance, the nitrogen hose remained connected to the filter and drain valves were left open allowing the hose to become
pressurised with liquid ammonia. While the hose was suitable for the pressures normally experienced under service with nitrogen, the hose was not suitable for the much higher pressures of liquid ammonia and as a result the hose burst in two places.
Consequences
The incident occurred as a result of the failure to follow the appropriate procedure and the company has taken the action of reviewing the competence of each operator to carry out the task. The company has also reviewed the operating procedures associated with the filter cleaning process to ensure they are appropriate.
Source: Department of Minerals and Energy, Australia
April 17, 2022
RELEASE OF TOXIC LIQUID THROUGH STEAM COIL LINE GASKET LEAK
Incident
A release of toxic liquid (containing arsenic trioxide)
from a storage tank occurred following the shutdown of a chemical plant.
The release occurred from a steam coil passing through a storage tank
used to store the solution during the shutdown. The release flowed into a
surface-drainage system,through a series of secondary catchment sumps
and ponds, into Cockburn Sound.
Cause
An investigation into the
incident has identified that the toxic liquid was released through a
hole in a gasket of a flange. The flange was located on the steam coil
pipework within the tank. It was found that the steam-line terminated
outside the bunded area in a partially-covered surface-drainage system.
Consequences
To
prevent a recurrence, all steam-lines within the plant were cut to
ensure that they terminated within the bunded area. The company has also
decommissioned the plant and will commission a new plant that does not
utilise arsenic compounds.
Source: Department of Minerals and Energy, Australia
April 13, 2022
FAILED GASKET DURING START UP
Incident
A mixture of process gases was released to the atmosphere through a failed gasket during the start-up of a chemical plant. Operators had just completed the start-up when they heard a large steam release and received alarms from ammonia detectors. The plant was shutdown, however the plume released travelled off-site necessitating the evacuation into refuges of a small number of workers on a neighbouring site. None was injured as a result of the release.
Cause
An investigation showed that the gasket failed as a result of a hole in a boiler tube which had allowed water to pass from the boiler side into the process side. The temperature generated during start-up caused the pooled water to rapidly boil leading to a surge in pressure which resulted in the failure of the gasket. Non-destructive testing of the boiler tubes showed gouge-type corrosion believed to have been caused by flow distribution problems in the boiler. This resulted in excessive metal temperature, which led to corrosion of the tube.
Consequences
A complete boiler inspection has now been conducted and boiler tubes showing signs of corrosion have been plugged off. Actions to prevent a recurrence include the addition of insulation at the top of all boiler tubes and further investigation into the boiler water chemistry to minimise potential for corrosion. The company has also modified the boiler to incorporate a drain valve in order to provide early warning in the event of water leakage.
Source: Department of Minerals and Energy, Australia
April 9, 2022
START UP INCIDENT IN AMMONIA PLANT
Incident
A mixture of synthesis gas and ammonia was released from an ammonia plant during the start-up process following a shutdown for maintenance. The release occurred from a high vent after ammonia had been allowed to collect in the vent system through a valve left open as a result of failure to tag the valve as out of service.
During the start-up, operators failed to control levels in the process, resulting in a high level alarm in an ammonia catchpot which led to a release of synthesis gas (as designed) into the vent system. However, as the vent system already contained ammonia, the gas mixture was forced out of the high vent. The wind direction took the gas cloud over an adjacent construction area on the same site resulting in fourteen
contract employees experiencing irritation and discomfort and later seeking medical attention. Six of these contractors were physically affected as a result of the exposure but nobody suffered serious or long-term injuries. The ammonia release dispersed and was not detected at neighbouring premises.
Cause
The incident was caused by a combination of factors including a failure of the tagging system and the failure to adequately control the catchpot level during start-up.
Consequences
The tagging system for equipment which is out of service, has been reviewed to ensure during maintenance there is no unauthorised operation of equipment. Resource allocation has been reviewed to ensure that process control is secured and level indicators in the catchpot have been assessed to ensure accuracy for process control. Also, workers at the adjacent construction site will now carry gas respirators at all times and will be notified of any operating conditions, such as start-ups and shutdowns, with the potential to lead to releases of gas.
Source: Department of Minerals and Energy, Australia
April 5, 2022
AMMONIA LEAK FROM REFRIGERATION SYSTEM
Incident
Approximately 56 kg of anhydrous ammonia was released to the atmosphere from
a 25-year-old refrigeration system. The emergency services stopped the leak by
closing an isolating valve. There was no injury. The site was not licensed for the
storage of anhydrous ammonia.
Causes
One valve failed to close and stop filling up the accumulator of the refrigerating
system. This resulted in flooding of the refrigeration compressor by liquefied
anhydrous ammonia, causing one of the compressor O-rings to fail, thereby causing
the release of anhydrous ammonia to the atmosphere. This points to an inadequate
maintenance program.
Consequences
The operator has been instructed to take appropriate measures so that the
refrigerating system complies with the relevant safety standard and the Dangerous
Goods Regulations. The operator was successfully prosecuted for failing to placard
the site and have a licence to store anhydrous ammonia.
Source: Department of Minerals and Energy, Australia
April 1, 2022
LOOSE BOLTS - CAUSES
Www.smartbolts.com/insights/loose-bolts-causes-ways-prevent/
A pressurized bolted flange joint assembly begins to leak, creating a
safety hazard. A rotor with its blades separates from the nacelle and
spins off a wind turbine, crashing to the ground. Under constant
vibration from the engine of an ocean freighter, loose bolts on a large
piece of mining equipment work their way off the bolted joints and roll
around the hull, inflicting further damage to the equipment.
March 28, 2022
March 24, 2022
March 20, 2022
Classic Marmaduke: Marmy's First Lesson
March 16, 2022
Is it Possible to Turnaround a Turnaround? - POWER Magazine
March 12, 2022
Use Dry Fog to Control Coal Dust Hazards
March 8, 2022
Give Your Plant a Dust Control Tune-Up
March 4, 2022
Coping with Coal Dust
March 1, 2022
SMARTBOLTS.COM - LOOSE BOLTS - CAUSES
http://www.smartbolts.com/insights/loose-bolts-causes-ways-prevent/
"A pressurized bolted flange joint assembly begins to leak, creating a safety hazard. A rotor with its blades separates from the nacelle and spins off a wind turbine, crashing to the ground. Under constant vibration from the engine of an ocean freighter, loose bolts on a large piece of mining equipment work their way off the bolted joints and roll around the hull, inflicting further damage to the equipment".
February 26, 2022
The Benefits of Explosion-Protected Cameras in High-Risk Environments
February 22, 2022
Safety and Digitalization Big Parts of Sustainability
February 18, 2022
Cybersecurity: The Biggest Threats Are Likely Within Your Organization
February 14, 2022
The Urgency of Protecting the Electric Grid from Cyberattacks
February 10, 2022
Practical guidelines for determining electrical area classification
February 6, 2022
Safe Temporary Power and Lighting Strategies For Refinery Turn-around Activities
https://www.electricalsafetypub.com/news-headlines/safe-temporary-power-and-lighting-strategies-for-refinery-turn-around-activities/
February 2, 2022
IGNITION SOURCES - IDENTIFICATION AND CONTROL HSE UK
Ignition sources may be:
Direct fired space and process heating;
Use of cigarettes/matches etc;
Cutting and welding flames;
Hot surfaces;
Heated process vessels such as dryers and furnaces;
Hot process vessels;
Space heating equipment;
Mechanical machinery;
Electrical equipment and lights
Spontaneous heating;
Friction heating or sparks;
Impact sparks;
Sparks from electrical equipment;
Stray currents from electrical equipment
Electrostatic discharge sparks:
Lightning strikes.
Electromagnetic radiation of different wavelengths
Vehicles, unless specially designed or modified are likely to contain a range of potential ignition sources
Sources of ignition should be effectively controlled in all hazardous areas by a combination of design measures, and systems of work:
Using electrical equipment and instrumentation classified for the zone in which it is located. New mechanical equipment will need to be selected in the same way. (See above);
Earthing of all plant/ equipment (see Technical Measures Document on Earthing)
Elimination of surfaces above auto-ignition temperatures of flammable materials being handled/stored (see above);
Provision of lightning protection
Correct selection of vehicles/internal combustion engines that have to work in the zoned areas (see Technical Measures Document on Permit to Work Systems);
Correct selection of equipment to avoid high intensity electromagnetic radiation sources, e.g. limitations on the power input to fibre optic systems, avoidance of high intensity lasers or sources of infrared radiation
Prohibition of smoking/use of matches/lighters
Controls over the use of normal vehicles
Controls over activities that create intermittent hazardous areas, e.g. tanker loading/unloading
Control of maintenance activities that may cause sparks/hot surfaces/naked flames through a Permit to Work System
Precautions to control the risk from pyrophoric scale, usually associated with formation of ferrous sulphide inside process equipment
Direct Fired Heaters, Hot Oil Systems and Processes Operating Above Auto-Ignition Temperatures
SOURCE: https://www.hse.gov.uk/comah/sragtech/techmeasareaclas.htm
January 28, 2022
Explosion Relief Vents for Highly Effective and Economical Explosion Protection
https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/explosion-relief-vents-for-highly-effective-and-economical-explosion-protection/
January 24, 2022
January 20, 2022
PREVENTING COMBUSTIBLE DUST EXPLOSIONS
https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/preventing-combustible-dust-explosions/
January 16, 2022
IGNITION RISKS OF ELECTROSTATIC CHARGE
https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/background-to-the-ignition-risks-of-electrostatic-charge/
January 12, 2022
SUGAR AS AN EXPLOSION RISK
https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/sugar-explosion-risk-grounding-helps/
January 8, 2022
DUST EXPLOSION HAZARDS
https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/dust-explosion-hazards/
January 4, 2022
IS TRUCK GROUNDING NECESSARY?
https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/is-truck-grounding-necessary/
January 1, 2022
WISH YOU A HAPPY NEW YEAR!
To all my readers, wish you a very Happy and Healthy 2022! Play your part in avoiding LOPC's!