General Diesel Discussion Talk about general diesel engines (theory, etc.) If it's about diesel, and it doesn't fit anywhere else, then put it right in here.
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Oilfield MythBuster

Old Jun 15, 2007 | 04:22 PM
  #16  
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From: Antioch, Ca
Originally Posted by Lil Dog
I have one on my truck, legislated for me to work on sites in the province of Alberta.

IF you don't believe it, check out the news for that huge refinery explosion in Houston last year. It levelled a few blocks of process equipment and was all sourced back to a Ford Service truck parked near a vessel that ran away.

BOOM....

I don't recall if there were fatalities or not.
Was it a ford? Seconds from disaster used a Dodge truck, but they claimed it was caused by something else, can't recall what though?

Found it!

Summary

During startup of the isomerization (ISOM) unit on Wednesday March 23, 2005 following a temporary outage, an explosion and fire occurred which killed 15 and harmed over 170 people at the Texas City refinery. It was one of the most serious industrial accidents in the preceding two decades. According to the report:

'Actions taken or not taken led to overfilling the raffinate splitter with liquid, overheating of the liquid and the subsequent overpressurisation and pressure relief. Hydrocarbon flow to the blowdown drum and stack overwhelmed it, resulting in liquids carrying over out of the top of the stack, flowing down the stack, accumulating on the ground, causing a vapour cloud, which was ignited by an unknown source [probably a vehicle engine or unshielded wiring in nearby office trailers].'

The report identified numerous failings in equipment, risk management, staff management, working culture at the site, maintenance and inspection and general health and safety assessments.
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Old Jun 15, 2007 | 10:15 PM
  #17  
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I have seen trucks running around the natural gas wells out here with sniffers on the front bumpers to detect fumes hopefully before a runaway occurs. I think the word hopefully is the operative word here.
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Old Jun 15, 2007 | 10:29 PM
  #18  
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The source of ignition for the BP explosion was an idling diesel truck. The source of ignition at a Formosa plant near me was said to be a diesel forklift.
Sometimes a quick ignition is a good thing. The larger the vapor cloud the bigger the explosion is going to be.
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Old Jun 15, 2007 | 11:09 PM
  #19  
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From: Okotoks AB
Every engine on every drilling rig and coil tuber we have has one OR multiple Roda Deco positive air shut offs.
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Old Jun 16, 2007 | 03:40 AM
  #20  
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That is why there are concerns about leaving your engine idling when you take on fuel? What happens if the nimrod next to you drops the gas nozzle on the ground hosing you with gasoline?

Anyone know how many RPM’s our engines have to turn before they self-destruct?
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Old Jun 16, 2007 | 05:53 AM
  #21  
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Originally Posted by kelley15


we call those valves rig savers here in colorado!
pretty neat system, but our pickups dont have them just our semi's.
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Old Jun 16, 2007 | 06:56 AM
  #22  
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From: Tomball, Texas
A runaway diesel cause the deadly BP plant explosion in Texas City several years ago that killed 15 people.

MikeyB
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Old Jun 16, 2007 | 08:17 AM
  #23  
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From: South Central Ohio
Originally Posted by mhuppertz
Any of you tong throwin' roughnecks ever had a truck keep running after it was shut off due to high levels of natural gas in the air out in the field? I have heard many stories......
Mark
A few years ago a backhoe broke a gas line out in the Amanda area, and two workers were burned to death. Run aways are common, there is no myth about it.......... Other workers that were not hurt said that the backhoe reved real high for a few seconds than blowed up. Everyone ran, but the ditch guy, and backhoe operator didn't make it...........
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Old Jun 16, 2007 | 08:18 AM
  #24  
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From: Tijeras, New Mexico, 7,000ft up
Originally Posted by Jim Lane
Anyone know how many RPM’s our engines have to turn before they self-destruct?
A Cummins engineer told me the mechanical redline of a 5.9 is somewhere around 5,000 rpm, but it varies a bit.
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Old Jun 16, 2007 | 08:38 AM
  #25  
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From: Trussville, Alabama
Spontaneous engine start

An engine can kick over on its own when a cylinder is left with an unignited fuel charge close to TDC. Eventually engine heat will ignite the mixture & kick the engine over. Not really an issue unless you drive a gasser or your engine happens to have a propeller on the end of the crank.
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Old Jun 16, 2007 | 08:44 AM
  #26  
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From: Burleson ,TX
Just an FYI if you have diesel run away at an oil field it would be my last day at that oil company. They have some seirous problems if they are having diesel run aways happen.
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Old Jun 16, 2007 | 09:51 AM
  #27  
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We have never had a runaway diesel before, but we have had a couple of flash fires from vapors coming off of a frac tank half full of condensate. The a/c compressor clutch switch caused the ignition source. Burned the trucks up pretty good. Scared the heck out of the guys sitting in the truck.
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Old Jun 17, 2007 | 05:58 PM
  #28  
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From: Republic of Alberta
I work for an oil company, we (as do almost all other companys) require positive air shut off on diesel engines to prevent run away.

It does NOT have anything directly to do with igition sources causing an explosion. ANY engine gas or diesel, (or a host of other things) is sufficant to cause igintion if the concentration of gas is right for an explosion not just a run away diesel.
The real reaon for positive air shut off is that at concentratrions of gas MUCH lower than what can ignite in the atmopshere can cause an engine to run away and the vehicle to smash into something.
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Old Jun 17, 2007 | 09:10 PM
  #29  
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From: Marshall, Texas
ASO'S(air shut offs) or rig savers are to positively close off the air supply to an engine that is operating on "an explosive air environment" location. On a well site, gas in enough ppm will cause the engine to overspeed.
I saw the aftermath of an engine that started itself once. Showed up an a timber yard one morning to work on a chipper, all the hands were down at the bottom of a hill in the edge of the woods trying to get a Prentice nuckleboom loader out. The guy that operated it left it ontop of a hill with shut off in gear. Found it the next morning in the woods.... it had spun the wheels in the soft dirt after it hit a tree. Not sure if it was still running when they got to it that morning...
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Old Jun 18, 2007 | 08:30 AM
  #30  
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From: VA Beach
Seems to me that if the environmental concentration of flammable ..anything is high enough to run an engine on the it's also high enough to ignite a humongus fireball.
I have seen overspeeds when the turbo oil seal went bad. And I've had my engine surge (scared begeebers outa me) when I was cleaning parts with gumout, but it went back down to normal really quickly.

But if the general atmpshere has a high enough concentration to burn then having your engine rev high would be a good thing as long as it was in gear and pointed away!
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