December 31, 2018
December 28, 2018
December 25, 2018
December 22, 2018
December 19, 2018
December 16, 2018
December 12, 2018
JR gestures | The Japan Times
JR gestures | The Japan Times: Dear Alice, Until recently I lived in Tokyo and commuted on the JR Chuo Sobu Line from Kameido Station. I made it a practice to ride in the last compartmen
December 8, 2018
Safety And Reliability: Two Sides Of The Same Coin
Safety And Reliability: Two Sides Of The Same Coin: Maintenance and reliability efforts are critically important in today’s industrial environment where increasingly complex and interdependent equipment are utilized.
December 3, 2018
Another Bhopal Anniversary.....
Time flies, but for the people who died a gruesome death on 2nd/3rd night, 1984, time was irrelevant. Today, we are in the cusp of technological innovations in process safety management, but the moot point is....can technology alone prevent disasters? Its people who make decisions, decisions that may compromise process safety and that could lead to a loss of containment incident. I am always of the view that technology can only be an enabler, if properly used.
There is a welcome change in India. Increasingly, boards of directors of chemical companies are focusing not only on occupational health and safety, but also on process safety. This is a welcome change. Lets pledge not to have another Bhopal again.
There is a welcome change in India. Increasingly, boards of directors of chemical companies are focusing not only on occupational health and safety, but also on process safety. This is a welcome change. Lets pledge not to have another Bhopal again.
November 30, 2018
Choke clearing incident
A senior
maintenance member of a two-man crew, and another employee were working from
an elevated work platform. The platform was mounted on the back of a
trailer, which was mounted to an asphalt tank. The employees had begun
bypassing the normal asphalt storage tank to prepare for its five-year
to seven-year cleaning. They placed a bypass valve in position to route
the asphalt from the permanent tank to the temporary, trailer-mounted
tank. Most of the asphalt piping was heated with a steam jacket
encircling the pipes. However, the piping that ran from the bypass valve
to the temporary tank was encircled with tubing that was heated by
steam. The employees complained that the steam tubing, also referred to
as steam tracing, was not wrapped tight enough, thereby preventing the
pipe from getting hot enough to turn the hardened asphalt back to its
liquid (melted) state. The employees then attempted to repair the
clogged pipe. As was reported to be the normal practice, they went to the end of the asphalt piping outlet and began heating
the last bend of the piping with a propane torch. The piping outlet was
located directly over the top of the manhole opening of the heated
asphalt tank. The tank was reported to be 300 degrees to 400 degrees
Fahrenheit, at that time. During the site visit, approximately five
hours later, the tank temperature gauge read approximately 260 degrees
Fahrenheit. After an undetermined amount of time that the employees were using the propane torch to heat the piping, an explosion
occurred in the asphalt tank. A witness described the explosion as a
flame which shot 30 feet above the manhole cover and quickly descended
back into the tank. This witness also stated that he could no longer
observe the employees standing on the platform. Employee #1 remained on
the platform and suffered asphalt burns and fractures to his face, where
an item impacted it during the explosion. Employee #2 fell from the
work platform, approximately 9 feet 5 inches to the concrete surface.
Employee #2 suffered asphalt burns to his body and face, in addition to a
hip fracture. A radio call for emergency response was broadcast
throughout the company. The company Emergency Response Team doused the
flames and provided initial first aid to Employees #1 and Employee #2.
Both employees were transported to the hospital.
Source:OSHA
Source:OSHA
November 26, 2018
November 22, 2018
November 18, 2018
November 10, 2018
Minimizing Fire and Explosion Hazards in dusty systems
Minimizing Fire and Explosion Hazards in Dusty Systems:
Having honest conversations about material handling hazards allow risks
to be properly addressed, thereby reducing fire and explosion threats.
November 6, 2018
November 2, 2018
12 Tips for Centrifugal Pump Safety
12 Tips for Centrifugal Pump Safety: Centrifugal pumps are used in industrial settings, and there are several steps that should be followed to ensure safe and efficient pump operation.
October 29, 2018
On April 6, 1994, a unit operator was conducting
rounds of the coker unit when he observed a leak coming from the
mechanical seal of the heavy gas oil pump of coker unit #1. The operator
decided to seek assistance; the head unit operator and six or seven
unit operators responded. The operators placed water and steam on the
leak to suppress the vapor from the seal. The head unit operator decided
to shut down the pump and transfer the product to the secondary pump.
As the operator shut down the primary pump, the mechanical seal blew,
causing a vapor cloud to generate from the seal. The operators continued
to put steam and water on the seal and isolated the pump from the pipe
line. The remaining product in the pipe line leading to the primary
heavy gas oil pump vaporized, leading to the dispersion of the vapor
cloud. The operators who responded were wearing bunker gear and several
wore emergency respirators. Those with respirators isolated the pump
from the pipe line by closing the suction and discharge valves. The
operators who were not wearing emergency respirators stationed
themselves upwind of the vapor cloud and put water on the cloud;
however, the wind changed direction several times, exposing unprotected
operators to vapors. Employees #1 and #2, two unprotected operators who
responded to incident, were brought to Hospital to
be treated for inhalation of hydrocarbons. Employee #1 was hospitalized.
Source: OSHA
Source: OSHA
October 24, 2018
Hexane Vapors Ignited By Static Electricity; Worker Burned
Employee #1 was standing at the exit end of a conveyor, peeling off a build up of hexane adhesive from the inside of a stainless steel dip tank. A static discharge of electricity, apparently generated by the peeling action, caused a flash fire. Employee #1 suffered second degree burns on the back of his hands and his upper chest and neck. The tank is 12 inches by 15 inches by 22 inches in size. The employee was pulling adhesive from the back side of the tank when the fire started. All the equipment in the area is grounded and bonded and approved for the location. The flash point for hexane is -23 degrees.
Source:OSHA
Source:OSHA
October 21, 2018
October 17, 2018
Explosion isolation flap valves provide reliable low-cost explosion protection
Explosion isolation flap valves provide reliable low-cost explosion protection: New explosion isolation flap valves are a reliable and cost-effective way to mitigate the risk of dust explosions propagating to upstream equipment.
October 14, 2018
October 10, 2018
October 6, 2018
October 2, 2018
September 29, 2018
September 26, 2018
September 22, 2018
September 18, 2018
Leak due to vibration
A specialized rubber manufacturing plant experienced leakage of a hexane solution from a pump discharge flange during use. The hexane vapor was ignited by a st atic electricity spark and a fire occurred. Apparently, the flange was loosened by vibrations from the pump.Routine operations were being carried out on site at the time of the accident.
The operation involved the transfer of a hexane solution from an un-reacted raw material recovery tank to the washing process through the outlet of the first flange of the pump. The hexane solution
leaked, ignited, and burned. The financial costs of recovery and lost production were significant.
Causes
The cause of the accident was a loose flange that resulted in leakage of a flammable substance. During the operation, a previously undetected cavitation in the pump produced significant vibration
which loosened the flange. As a cause of the ignition it was considered that the hexane was charged when it spouted from the flange, and static electricity was discharged; then hexane vapor ignited
and a fire occurred.
It was considered that the vibration might have been intensified by the passage of an insoluble polymer lump through the pump, a malformation in the substance generated on the piping wall. In addition, a reducer connected a 3-inch (~75mm) flange of the discharge pump to 6-inch (~150mm) piping. The looseness of this flange might have been accelerated when the force
of vibration was added on the piping.
Lessons learned
Vibrating equipment can increase potential for stress fractures and gaps from loosely fitting interfaces, all of which can be sources of leaks that, if undetected, may result in an accident. It is necessary to pay sufficient attention to vibrating equipment, especially pumps that may be found in many processes throughout the site. Control measures to mitigate potential risks could include regularly scheduled inspections in line with existing technical standards or in-house experience, particular attention to small-bore piping (vulnerable to fatigue), installation of a vibration monitor to detect and locate abnormal vibration patterns, as well as other measures available in guidance
on vibrations from numerous sources.
Source: European Commission
The operation involved the transfer of a hexane solution from an un-reacted raw material recovery tank to the washing process through the outlet of the first flange of the pump. The hexane solution
leaked, ignited, and burned. The financial costs of recovery and lost production were significant.
Causes
The cause of the accident was a loose flange that resulted in leakage of a flammable substance. During the operation, a previously undetected cavitation in the pump produced significant vibration
which loosened the flange. As a cause of the ignition it was considered that the hexane was charged when it spouted from the flange, and static electricity was discharged; then hexane vapor ignited
and a fire occurred.
It was considered that the vibration might have been intensified by the passage of an insoluble polymer lump through the pump, a malformation in the substance generated on the piping wall. In addition, a reducer connected a 3-inch (~75mm) flange of the discharge pump to 6-inch (~150mm) piping. The looseness of this flange might have been accelerated when the force
of vibration was added on the piping.
Lessons learned
Vibrating equipment can increase potential for stress fractures and gaps from loosely fitting interfaces, all of which can be sources of leaks that, if undetected, may result in an accident. It is necessary to pay sufficient attention to vibrating equipment, especially pumps that may be found in many processes throughout the site. Control measures to mitigate potential risks could include regularly scheduled inspections in line with existing technical standards or in-house experience, particular attention to small-bore piping (vulnerable to fatigue), installation of a vibration monitor to detect and locate abnormal vibration patterns, as well as other measures available in guidance
on vibrations from numerous sources.
Source: European Commission
September 14, 2018
Common Causes of Gasket Failure
Common Causes of Gasket Failure: During the course of our 50 years in business, Associated Gaskets has seen many different types of gasket failures. Sometimes these were seen late at night when we were called out to help with an emergency, other times it was when one of our own gaskets was returned after failing …
September 10, 2018
September 6, 2018
Global warming and its effect on process incidents
As the effects of global warming are being felt, chemical industries must acknowledge the fact for planning for natural disasters. The "Fire from ice" video about the Valero refinery incident and The Arkema incident due to Hurricane Harvey are two examples related to climate. Cyclone maximum wind speeds are increasing and past weather data may not be a reliable predictor about the future. What are you doing about it?
September 3, 2018
Gasket failure incident
On 5th January 2008 a production operator discovered a fair sized phenol leak in the phenol pump house next to the phenol storage tank. One of the gaskets on the flange connection on the outlet pipe of the tank had failed. The head of the operations department tried to stop the leak by tying a rubber belt around the flange. In the meantime, an operator sprayed water on the flange to avoid contact with phenol as much as possible. The phenol that had leaked was collected in a catchment pit of 20 m3 underneath the pump house. This catchment pit had a high level alarm, but it was not functioning at the time of the leak. The company was not aware of the malfunction because the alarm was not subject to periodic inspection.
An attempt was made to close the only manual valve on the pipe,located between the inner and the outer tank shells, but the valve spindle broke off during this manipulation, so the line could not be
shut off. After the temporary repair of the flange connection, three leaks continued to release phenol, which were also collected in the catchment tank. It was not allowed for the employees to enter the
pump house while the phenol was leaking. To clean up the catchment pit, the company provided a waste tank big enough to contain all the leaked phenol. When starting to pump the phenol from the catchment tank to the waste tank, it was discovered that the catchment pit had overflowed. Part of the
phenol/water mixture had passed over the rim of the open pit into the municipal sewer system. At the time, it was not yet known how much phenol had leaked to the sewer system.
On 7th January 2008 it was decided to start up the phenol-based batch production to consume all phenol in the storage tank since the phenol tank had to be taken out of service in order to replace
the gasket on the flange. On January 8th, after a few batch productions, it was found out that the level indicator in the phenol storage tank had become stuck since the last control of the level on 4th January (comparison of manual level measurement with level indicator). Only at that moment did the company realize that 25t of phenol had leaked out of the tank. The catchment pit probably
collected most of the release, but more than 5t of the phenol spilled into the municipal sewer. No consequences were reported as a result of the release into the municipal sewer. A specialized
company was hired to repair the remaining phenol leak.
Causes
In this case, a variety of causes contributed to the accident. The direct cause was the degradation of gasket that caused the leak. After the flanges and valves were replaced following the accident, it
was discovered that the valve broke down because the gasket next to it had been reacting with phenol over the course of many years, leading to a solid deformation that prevented the valve from moving,
hence, the valve could not be closed. The spindle of the manual valve at the tank broke off as a result of the deformation of the adjacent gaskets.
Source: European commission
An attempt was made to close the only manual valve on the pipe,located between the inner and the outer tank shells, but the valve spindle broke off during this manipulation, so the line could not be
shut off. After the temporary repair of the flange connection, three leaks continued to release phenol, which were also collected in the catchment tank. It was not allowed for the employees to enter the
pump house while the phenol was leaking. To clean up the catchment pit, the company provided a waste tank big enough to contain all the leaked phenol. When starting to pump the phenol from the catchment tank to the waste tank, it was discovered that the catchment pit had overflowed. Part of the
phenol/water mixture had passed over the rim of the open pit into the municipal sewer system. At the time, it was not yet known how much phenol had leaked to the sewer system.
On 7th January 2008 it was decided to start up the phenol-based batch production to consume all phenol in the storage tank since the phenol tank had to be taken out of service in order to replace
the gasket on the flange. On January 8th, after a few batch productions, it was found out that the level indicator in the phenol storage tank had become stuck since the last control of the level on 4th January (comparison of manual level measurement with level indicator). Only at that moment did the company realize that 25t of phenol had leaked out of the tank. The catchment pit probably
collected most of the release, but more than 5t of the phenol spilled into the municipal sewer. No consequences were reported as a result of the release into the municipal sewer. A specialized
company was hired to repair the remaining phenol leak.
Causes
In this case, a variety of causes contributed to the accident. The direct cause was the degradation of gasket that caused the leak. After the flanges and valves were replaced following the accident, it
was discovered that the valve broke down because the gasket next to it had been reacting with phenol over the course of many years, leading to a solid deformation that prevented the valve from moving,
hence, the valve could not be closed. The spindle of the manual valve at the tank broke off as a result of the deformation of the adjacent gaskets.
Source: European commission
August 31, 2018
August 28, 2018
August 27, 2018
Rupture of sulphuric acid tank
On 4th February 2005 a storage tank containing 16,300 t of
96 % sulphuric acid ruptured. The entire contents of the tank were spilled out
into the bund and then overflowed out into the nearby dock. The environmental
consequences of the accident were quite significant,the sulphuric acid emission
had a serious effect on local flora in the inner and deepest parts of the
harbor and harbor entrance area. When the sulphuric acid came into contact with
the salt water an exothermic reaction occurred, producing a vapour cloud
consisting of hydrogen chloride that drifted northwards along the coastline in the
direction of the wind. Fortunately, the wind was blowing towards the sea and
away from populated land areas and the cloud diluted very quickly. After the
spill approximately 2,000 t of contaminated sulphuric acid remained in the
bund. The acid also soaked into about 100,000 square metres of the ground
surrounding the spill.
Causes
The cause of this incident was a leak in an underground
coolant supply pipe of reinforced concrete installed over forty years before that
resulted in a weakening of the ground under the tank farm. Apparently, water
forced its way out of the pipe, eroding the ground near and around the
sulphuric acid tank. This erosion damaged the ground under the tank which
ultimately failed due to the lack of support of the tank floor. A study of the
appearance of the involved part of the coolant supply pipe suggests that the
corrosion was a result of an acidic attack on the concrete.
Important findings
• The damage indicates that the acid exposure occurred over
a long period of time. However, it was not possible to determine the exact duration
of the exposure.
• The pipe had been in use over many years and the operator
had mno suspicion that the pipe was suffering severe degradation. The inspection
of the failed pipe after the incident detected little or no internal corrosion,
but heavy external corrosion to the concrete. In certain places the concrete
had corroded so severely that the reinforcing steel was exposed.
• According to the German standard, DIN 4030 (equivalent to
the European standard, EN 260) a strong attack on concrete occurs if the pH
level in surrounding water is < 5.5 and a very strong attack can occur if
the pH level is < 4.5. Fifteen years before the accident a ground pollution
study was carried out in the area, during which one of the sample taking points
was close to the failed coolant supply pipe. At this point the pH level was
measured at 4 in the shallow groundwater. With this knowledge the company drew
the conclusion that this pH level entailed risks for strong acidic attackson
the concrete.
Lessons learned
• The uneven corrosion on the outside of the pipe can
possibly be explained by the fact that it lay partly in groundwater flow. In
this environment, the acid can pass through the barrier more easily, and the
reaction products (gypsum) formed can be more easily dissolved. As such, the
concrete barrier was not as effective as on the part of the pipe that remained
in drier surroundings. Therefore, concrete piping exposed to ground water
should be should be subject to protective measures, monitoring and inspection
to take into consideration the increased risk from groundwater exposure.
• Similarly, underground piping that entail risks to
foundations should be inspected and measured..
• There are a number of strategies that can be applied to
piping where there is accelerated potential for degradation or where there are
high consequences should significant degradation occur.
Pipes may, for example, be tested for stability (remains in
place) and hydraulically checked on a regular basis. Alternatively,
consideration should be given to positioning the pipe above ground. The pipe
could also be placed in casings, especially where a leak may cause damage to
the surroundings or where pressure and ground deformation may cause damage to
the pipe.
Source: European commission