Explosion caused by OFF power tool?

[tinysailor]

Sorry if I've submitted this info a few times, my laptop's not playing the game.

Some useful reference material:

AS/NZS 2906:2001 Fuel containers - Portable-plastic and metal (This is an Australian Standard)

Service stations - Filling portable containers with flammable liquids

The link below is a WorkSafe (Vic) publication available online

https://www.worksafe.vic.gov.au/__da...le_liquids.pdf

AIP CP-008 (2000) PRECAUTIONS AGAINST ELECTROSTATIC IGNITION DURING TANK VEHICLE LOADING

AIP (Australian Institute of Petroleum) is now defunct however readily used as reference material in the industry. Its a good publication regarding managing static.

Pembroke Refinery Explosion 2011

The link below provides a lot of useful information. I can’t remember if 4 or 5 people were killed during tank clean out operations. I was privy to certain information and know that vapour and static were leading contributors.

http://www.hse.gov.uk/comah/chevron-refinery.htm

I hope this information will assist in managing the risks associated with fuel.

Best regards,

tinysailor

[valhalla360]

Theoretically possible but pure speculation and better odds of winning the lottery.

Sounds like someone is afraid of using gasoline onboard and is trying to justify it by making up stories.

[LakeSuperior]

Critical to remove the tank from the dingy before filling on a calm day. If you add 5 gallons to the tank at least 5 gallons worth of explosive fumes flow out of the tank and into the dingy.

Same problem with filling a tank in a pickup bed. One could end up with the bed partially full of gas fumes. Think invisible pond of fumes. I suspect this is a bigger issue than the grounding problem when it comes to pickups.

[zeehag]

i think something else started it. there were enough other things making static electricity and sparkage the off tool aint it.
is a sad day when boats burn, especially when it was for no earthly or reasonable reason.
stay safe amigo.

[sartorst]

My grand father who worked at a gas plant told us several story's in which a worker would have to strip down naked to prevent static and run into the plant to close a valve to stop a leak. Safety standards were different in the 50s-60s

[socaldmax]

Originally Posted by sartorst

My grand father who worked at a gas plant told us several story's in which a worker would have to strip down naked to prevent static and run into the plant to close a valve to stop a leak. Safety standards were different in the 50s-60s

That's as good a reason as any to hire a hot secretary.

[ramblinrod]

Originally Posted by LakeSuperior

Critical to remove the tank from the dingy before filling on a calm day. If you add 5 gallons to the tank at least 5 gallons worth of explosive fumes flow out of the tank and into the dingy.

Same problem with filling a tank in a pickup bed. One could end up with the bed partially full of gas fumes. Think invisible pond of fumes. I suspect this is a bigger issue than the grounding problem when it comes to pickups.

Interesting theory, but I completely disagree.

Plastics easily develop a static charge. Many times, when one steps out of a vehicle and touches a plastic bedliner they receive a static shock. (Just the air flow across the plastic on a dry day can produce a static charge.)

When one brings a fuel nozzle near a plastic object, having a high enough static charge, a spark jumps the gap, just like the spark of a spark plug in a gasoline engine.

The is why any portable fuel tank should be removed from any surface (dinghy, truck bed, or whatever), especially a plastic one (highly non- conductive and able to hold a static charge), and placed on the ground, cement, or asphalt.

When this is done, there is far less risk of static potential between the tank and fuel nozzle.

Regardless, a spark will generally ignite the fumes nearest the source of the spark. Fumes expelled from a tank, dissipate quickly.

[Sailorbob8599]

Originally Posted by sartorst

My grand father who worked at a gas plant told us several story's in which a worker would have to strip down naked to prevent static and run into the plant to close a valve to stop a leak. Safety standards were different in the 50s-60s

Static is an inherent problem with synthetic clothing ... I wear cotton and wool clothing aboard boat. Not necessarily to avoid static, although that's a definite side benefit, but more to help retain body heat should I inadvertently fall overboard.
Seems to me, traditional Royal Navy uniforms were all wool during WWII, but I don't know if that is so today. I had an uncle who was torpedoed three times during the war, each time ending up in the ocean for a number of hours. He claimed his wool uniform saved him from severe hypothermia.
He was rescued the first two times by other R.N. ships and returned to service. The third time he was not so lucky. He was on the Murmansk run as it was known; picked up by a German navy ship, he ended up a P.o.W. for 2-1/2 years.
There again, he could have been killed like so many of his ship-mates. We were just happy to see him eventually return home, even though he suffered from 'shell shock' (now known as PTSD) for the rest of his life.

[LakeSuperior]

Originally Posted by ramblinrod

Interesting theory, but I completely disagree.

Plastics easily develop a static charge. Many times, when one steps out of a vehicle and touches a plastic bedliner they receive a static shock. (Just the air flow across the plastic on a dry day can produce a static charge.)

When one brings a fuel nozzle near a plastic object, having a high enough static charge, a spark jumps the gap, just like the spark of a spark plug in a gasoline engine.

The is why any portable fuel tank should be removed from any surface (dinghy, truck bed, or whatever), especially a plastic one (highly non- conductive and able to hold a static charge), and placed on the ground, cement, or asphalt.

When this is done, there is far less risk of static potential between the tank and fuel nozzle.

Regardless, a spark will generally ignite the fumes nearest the source of the spark. Fumes expelled from a tank, dissipate quickly.

First, I agree that static electricity arcs/sparks ignite gasoline and must be avoided. The first lesson I learned working a summer job in a Great Lakes marina is how to fuel a boat. The lesson there was to not tap the gas nozzle on the fill pipe in order to shake off any lingering fuel drops. Make contact, fill, and remove the nozzle.

So answer this. If a non-conductive plastic tank is placed on the ground how does that mitigate a static charge building up on the upper part of the tank? The plastic is not conductive. Problem not solved.

Many trucks including mine do not have plastic bed liners.

From when I was a child the instructions were not to fill the outboard motor gas tanks in the truck bed or inside the open fishing boat. I have always assumed the reason was to avoid collecting gas fumes in an effective swimming pool. Gas fumes will indeed pool and linger on a calm day.

[ramblinrod]

Originally Posted by LakeSuperior

First, I agree that static electricity arcs/sparks ignite gasoline and must be avoided.

So answer this. If a non-conductive plastic tank is placed on the ground how does that mitigate a static charge building up on the upper part of the tank? The plastic is not conductive. Problem not solved.

The air surrounding (on the surface of) the fuel tank is a better electrical conductor than the fuel tank itself.

If any part of the tank is brought into proximity of a surface that will cause a spark to jump the gap, then making direct contact with that surface will provide even less resistance for static discharge. Once the static discharge is dissipated to the degree a spark will not jump an air gap, the risk of spark between tank and fuel nozzle is reduced.

[hellosailor]

You know, in aviation, whether you are pouring or pumping "gasoline" up or down, between metal and plastic or anything, the SOP is to connect the two containers with a grounding wire first, before there is any pouring, to eliminate static sparks that could ignite the vapors.


And there have been fires at gasoline stations, allegedly from sparks while people were fueling their cars. (And not smoking or using a cell phone.)


So, gasoline? After all, it is SUPPOSED to explode.


As thinwater said, sometimes "conductive" materials are designed to be of a high resistance. That way they allow a charge to bleed off s l o w l y which also discourages sparks from forming, I would think. 3M makes conductive wrist bracelets for people working with electronic components, and they're "carbon" and "fabric" for the most part. They do NOT recommend just wiring your wrist up to ground.(G)

Personally, I like to keep an extinguisher (and preferably a helper) nearby, with the safety pin out and ready to use, whenever "fuels" are being splashed around. The same way some air crews do. For the same reason.


Now, as to "grounding" anything on a boat, especially with a mains-powered power tool around...

[thinwater]

Originally Posted by LakeSuperior

So answer this. If a non-conductive plastic tank is placed on the ground how does that mitigate a static charge building up on the upper part of the tank? The plastic is not conductive. Problem not solved.

Plastics used for gasoline systems are conductive. It is very slight, like humid air, but it is enough to bleed off the high voltage charge. This is one reason it is CRITICAL to use fuel rated hoses. I once saw a vacuum truck destroyed because they used septic tank hose to pump a 5%gasoline/95% diesel mix.

[thinwater]

Originally Posted by LakeSuperior

Many trucks including mine do not have plastic bed liners.

They are sitting on non-conductive tires that rotate and build charge. In the aforementioned explosion the truck was isolated from the ground on tires.

These problems are rare because there is redundancy in the equipment. For example, gasoline station hoses have wire that runs from pump ground to nozzle. But when you do non-standard transfers it is always possible to defeat the redundancy.

[LakeSuperior]

Originally Posted by thinwater

They are sitting on non-conductive tires that rotate and build charge. In the aforementioned explosion the truck was isolated from the ground on tires.

These problems are rare because there is redundancy in the equipment. For example, gasoline station hoses have wire that runs from pump ground to nozzle. But when you do non-standard transfers it is always possible to defeat the redundancy.

I have never picked up a static charge from a vehicle even in super low humidity weather.

A wire to ground on the fuel nozzle doesn't help the receiving end of the nozzle prevent a charge transfer through air.

Perhaps the carbon in the rubber bleeds static charge to ground.
Additionally, cars would explode regularly if they picked up static charge.

Still not buying the pickup bed static charge mechanism.

[thinwater]

Originally Posted by LakeSuperior

I have never picked up a static charge from a vehicle even in super low humidity weather.

You folks need to listen if you want to learn anything. This is not common, but it absolutely does happen. This is established fact, not my theory.

https://www.youtube.com/watch?v=tuZxFL9cGkI

This is one reason there are stickers at pumps warning you never to reenter you vehicle, and that if you do, to ground yourself to the pump first. Look next time you get gas.

Some people listen, others need to pee on the electric fence. These things are not common and they will almost certainly never happen to you. Roll the dice. But personally I cannot think of anything worse than being burned up by gasoline. I've done several accident investigation as part of my job, and they are NEVER pretty.