BP Explosion
BP Explosion
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RE: BP Explosion
Vita sine litteris mors est.
RE: BP Explosion
I haven’t heard anything about the specific type process unit involved. But talking to a buddy that has worked at the plant he said that he has heard from several sources that stared with problems with a flare stack. This is also mentioned in the side bar of the following. All dead are contractors.
http://
RE: BP Explosion
RE: BP Explosion
John
RE: BP Explosion
http:/
Vita sine litteris mors est.
RE: BP Explosion
RE: BP Explosion
Vita sine litteris mors est.
RE: BP Explosion
“BP spokesman Bill Stephens Friday said the fire, which erupted at 2:45 p.m. Tuesday from a three-fourth inch bleeder valve on a furnace line in the plant's isomerization unit, was quickly put out with a hand-held fire extinguisher.
``We will look at it with all the other information and see if there is any connection,'' Stephens said. ``Fires are not supposed to happen.''
The seconds-long blaze was attributed to a missing valve plug.
The explosion at the 1,200-acre plant bordering Texas 146 occurred as workers attempted to restart the refinery's isomerization unit after a two-week shutdown for maintenance. "This is one of the most vulnerable times," said John Miles, regional director for the U.S. Occupational Safety and Health Administration.”
RE: BP Explosion
RE: BP Explosion
Laid on my desk this week was a safety bulletin outlining my company's plans to reduce the risk of temporary trailers/structures used in the plant confines.
I have heard (rumor mill only) that OSHA (?) will be developing a facility siting requirement - dealing with restrictions for trailers/structures within blast overpressure zones - as a result of the explosion at BP.
Anyone else have similar comments?
~NiM
RE: BP Explosion
HAZOP at www.curryhydrocarbons.ca
RE: BP Explosion
RE: BP Explosion
http://bpresponse.org/external/index.cfm?cid=946
Edward L. Klein
Pipe Stress Engineer
Houston, Texas
"All the world is a Spring"
All opinions expressed here are my own and not my company's.
RE: BP Explosion
RE: BP Explosion
BTW, maintenance bypasses might still permit such operator errors but not without multiple alarms. Normally the shutdown system alarms and indications are still active even if the shutdown is bypassed. No startup bypass would typically apply to high level. A startup bypass for the low level would likely become active once the level was established.
John
RE: BP Explosion
BP Revises Blame for March Refinery Blast
http:/
Vita sine litteris mors est.
RE: BP Explosion
RE: BP Explosion
Vita sine litteris mors est.
RE: BP Explosion
Veritatis una vis, una facies est.
Seneca
RE: BP Explosion
The splitter column have been out of service during one month and steamed out to remove hydrocarbons from February 26 to 28. The steam is usually prone to tray valves because after steaming the valves stuck with scale and after start up the vapor pressure of the ascendant gases is not enough to unplug the valves and the column get flooded. The flooding of the column was responsible for the high peak pressure of 63 psig when the maximum relief pressure was 42. In my opinion the high pressure in the splitter was responsible for the hydrocarbons release followed by explosions in downward equipment.
When tray columns are shut down for long time, just after start up is important to mechanically knock the valves or flush the column with water to dissolve the scale around them. The steam degasification should be done only just after start up.
Luis Marques
RE: BP Explosion
- workers not following procedures (managers, ceo's are also workers)
- no supervision on critical moments
- paperwork that is signed (Management of Change) after parking trailers
- no crosscheck with outside instruments (column filling with no outlet and estimated time frame)
- people taking 100% readings for granted, would rise serious questions about the credibility of maintenance
- outdated technology (blowdown drum)
- tie-in instead of phase out of connections to blowdown drum
are all signs of management deficiencies, the traditional part of the iceberg that is underwater.By the way if non-technical journalists are interpreting the report as:
you will get this mess, especially with a sue-happy public.
I saw in the report a summary of facts stated with evidence (no comments of spokesman this or union leader that).
RE: BP Explosion
I have been in only two turnarounds but I question this statement.
- Shutdown
- Drain liquid in the tower
- Steam-out and drain condensate, this is done to get the column gas-free if you are going enter (confined space entry permit)
- Isolate!! Blank or Blinds list needed
- Inspection / Repairs
- Steam out again!!, you don't want oxygen in the system, hydrocarbons, oxygen and heat is an explosive mixture. That is why flare headers always have a slight positive pressure, if not lpg or fuel gas is spiked in to keep the air (oxygen) out
- pressure up with lpg or gas
The last step is start-up (introducing feed)RE: BP Explosion
When a unit is planned for shut down, all degassing procedures should be followed. If columns are not supposed to be open for maintenance purposes, just after start up, is important to flush the column with water to dissolve the scale around valve trays to be sure that tray valves are free and able to tilt around tray holes to perform later its rectification job. If valve trays stay glued with scale, later on, the column will get flooded. The steam degasification to remove oxygen should be done only just after start up followed with nitrogen pressuring.
In Texas City the splitter was shut down on February 21, steamed out 26 to 28, drained on March 14 followed by nitrogen pressuring and depressurized on March 21. Cold feed was brought on March22/23.
Luis Marques
RE: BP Explosion
Of course we don't know the time frame/problems they were experiencing, but from the report it was stated that 2 start-up procedures were used.
Just curious.
RE: BP Explosion
http://www.reliabilityweb.com/art05/bp_tx.htm
RE: BP Explosion
Good link. I received the slide show .pps a few days after the event. Pretty easy to note that it was not prepared on a BP/Amoco computer. Also when you take a closer look at the back of the firefighter turnout coats you'll note that not everybody belongs to the BP/Amoco refinery. It was a mutual aid situation. I'm wondering if anyone can substantiate the rumor that the person who shot the photos and/or released the slideshow is no longer employed...
jt
RE: BP Explosion
BP is coming down hard on some operators and supervisors apparently.
JMW
www.ViscoAnalyser.com
RE: BP Explosion
I have read the comments could you please answer some questions I had regarding the distillation column/ system.
I'm not familiary with the oil industry. So excuse me ignorance.
> Is Rafinate a trade name for mixture of heptane +.
> Whats the difference between light and heavy rafinate - BP are they both mixtures.
> It is common for oil industry columns not to have independent high level switches on distillation columns ? (I never design a column without one)
> on common vent stacks do you not normally have level alarms. (or even trips SIS2/3 .... /ESD 2,3)
> Why do they use fin fans not water cooled.
RE: BP Explosion
It is also common to have high level switches that triggers alarms, emergency shutdowns etc.
Vent stacks like blowdown drums are dangerous, almost every where in the world they are substituted by flare systems.
Almost all hydrocarbon vapors are heavier then air, and will come down and acumulate in pits, sewers etc, if they are not flared (burned).
On the vent stacks there must be high level alarms, ESD's should be a difficult if different units are connected to the blowdown drum. Imagine 5 independent units connected, an upset in one of them could imply shutdown of all the others.
RE: BP Explosion
In case of a trip / ESD in a unit, the quantity of gases to be vented increases, since their normal stream is disrupted. Stagnant gases combined with heat will build up pressures that must be released to the stack/flare.
RE: BP Explosion
if you use two independent level transmitters which are mounted separately on the column you can go without switches etc.
They must be used as independent signals etc. So each of the two must be able to trigger actions (e.g. alarms, ESD's etc.).
Grtz
Ben
RE: BP Explosion
transmitters instead of process switches,
seperate systems for "basic regulatory process control" and safety shutdown,
different technologies for the measurement devices for the diffent systems to avoid common mode failures,
increasing levels of backup measurement where the safety integrety level for a process sub-system is elevated,
...
The unit at BP was not new. Typically, a process hazard analysis is required every five years to re-visit safety levels, monitor management of change, ...
The refinery codes and standards are typically not as stringent as required for offshore oil and gas production. Thus, some things that are done within some facilities are not requirements.
John
RE: BP Explosion
You state that stagnet gasses will need to be released to the flare stack does this mean that the column runs very cold ? or is there a reaction. Otherwise I dont understand why this is an issue. My understanding of distillation columns.
If you stop feed/heat then as long as the MAWP of the column is higher than the saturated vapour pressure of the lightest component at the base P then you dont have an issue. Or is this a Low MAWP column because its cold.
RE: BP Explosion
If the heater feed pump trips, burners must trip also (interlock), the case is to get the feed running as quick as possible to prevent overheating of tubes and have a tube burst. As long as the product is running it is cooling also the pipes.
On the flare system various PSV's are coupled not only from the destilation tower. A trip results in temperature spikes in various points of the system, thus hydrocarbon gases are liberated which have to be removed by the flare system.
Whenever there is a trip the flames of the flare get higher, yellow with black smoke, indicating that an abnormal quantity of gases is flared.
Imagine you turn off the power switch of the whole plant (every operators nightmare). Theoretically you are not entering energy so things will cool off. The flare will be x-times higher then normal releasing "trapped energy"
The point is not only the distillation column, but the distillation train must be considered. There is no reaction involved in distillation (vacuum system) but when the temperatures run to high, coke will be formed in the pipe, which is a chemical reaction.
RE: BP Explosion
HAZOP at www.curryhydrocarbons.ca
RE: BP Explosion
HAZOP at www.curryhydrocarbons.ca
RE: BP Explosion
RE: BP Explosion
See second to last paragraph on page 4 of:
http://www
Main incident page at:
http:/
jt
RE: BP Explosion
I suppose there will be an addenda to the final report.
RE: BP Explosion
http://
Larry
RE: BP Explosion
Larry
RE: BP Explosion
We have fuel and air...where is the spark. From one of the medical respondants to the incident I have heard several injuriees stating that someone was running away yelling that his truck would not turn off (diesel). Funny how the people who heard/saw this and took off are the ones that lived.
Anyone else have any tidbits as to the ignition source?
Incidentally I know of a few refineries that have started turning diesels away at the front gate if they are not equipped with an intake shutoff valve.
RE: BP Explosion
The following message is from the United States Chemical Safety and Hazard Investigation Board, Washington D.C.
CSB Investigators Continue Assessment of July 28, 2005 explosion and fire at BP Amoco’s Texas City Refinery
Washington, DC, July 25, 2005 Investigators from the U.S. Chemical Safety and Hazard Investigation Board today continued a preliminary investigation into the explosion and fire which occurred at the BP Amoco Texas City refinery last Thursday, July 28, 2005.
CSB Investigators Giby Joseph and Francisco Altamirano visited the site where the accident occurred for a second time. They continued interviewing plant operators, and requested additional documentation and other information from the company regarding the chemical process underway at the time of the accident. They arranged for eyewitnesses to be interviewed early in the week, and announced their intention to arrange testing protocols -- to examine a pipe that separated from a flange -- to determine what caused it to fail.
Mr. Joseph said the explosion occurred during what appeared to be a normal operation in the reactor section of the plant’s Resid Hydrotreater Unit # 1, or RHU, when an eight-inch pipe connected to a heat exchanger failed at the flange. (Flanges are pipe fittings which are used to connect equipment such as pipes and valves.)
“Recycled gas, primarily hydrogen, was suddenly released when the pipe broke away. The hydrogen, under high pressure and temperature, was ignited, sending a large jet fire shooting an estimated 75 feet westward from the flange. Damage was localized along that fire path,� Mr. Joseph said, addition that initial information indicates the hydrogen was pressurized at approximately 3,000 pounds per square inch at a temperature of over 500 degrees Fahrenheit. Heat from the fire deformed piping and bent structural beams, he added.
Investigators said the reactor combines heavy crude oil with hydrogen as part of the conversion to lighter products. There were no injuries from the incident. Investigators were told that 13 workers were in the area, including several contractors. BP has provided CSB investigators with handwritten eyewitness statements from employees, who will be interviewed this coming week by the CSB.
The incident occurred during routine operations, and not during maintenance or a startup. CSB investigators say that witnesses report having received no warning indications before the pipe failure and explosion.
Investigators Joseph and Altamirano are part of the CSB team currently investigating the explosion and fire which occurred at BP on March 23, 2005, killing 15 workers and injuring more than 170 others. After an initial assessment is made of the July 28 accident, the Board will determine the extent to which the latest accident will be further investigated, and whether it would form part of the ongoing investigation.
CSB Chairman Carolyn Merritt said, “Although this latest explosion and fire fortunately caused no injuries, such accidents are not an acceptable part of normal operations. The accident occurred at an entirely different part of the Texas City facility, but we are interested in knowing whether the two accidents share any common root causes such as lack of an effective mechanical integrity program. Such a program would make sure the equipment is safe and serviceable.�
Lead investigator Donald Holmstrom, in charge of the March 23 explosion investigation, will arrive on site Monday evening.
The CSB is an independent federal agency charged with investigating industrial chemical accidents. The agency’s board members are appointed by the president and confirmed by the Senate. CSB investigations look into all aspects of chemical accidents, including physical causes such as equipment failure as well as inadequacies in safety management systems. Typically, the investigations involve extensive witness interviews, examination of physical evidence, and chemical and forensic testing.
The Board does not issue citations or fines but does make safety recommendations to plants, industry organizations, labor groups, and regulatory agencies such as OSHA and EPA. The Board designates formal responses to its recommendations as acceptable or unacceptable, open or closed. Further information about the CSB is available from www.csb.gov.
For further information, contact Sandy Gilmour, cell 202.251.5496.
ATTN NEWS MEDIA: We do not expect to issue further information Sunday July 31, 2005.
This message was transmitted at 2:53 PM Eastern Time (U.S.A.) on July 30, 2005.
________________________________________________________
Visit us on the World Wide Web at http://www.csb.gov
Larry
RE: BP Explosion
HAZOP at www.curryhydrocarbons.ca
RE: BP Explosion
Larry
RE: BP Explosion
I was referring to the first explosion, not the latest one.
RE: BP Explosion
What interesting is the budget for the CSB. Chump change for an outfit like BP. They will probably buy them by having the government privatize the CSB.
http://t
RE: BP Explosion
John
RE: BP Explosion
Looks like substantial progress.
Larry
RE: BP Explosion
Larry
RE: BP Explosion
http://p
RE: BP Explosion
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