diesel tank Welding on top of fuel tank

[MtB]

2 minutes ago, hawkesmith said:

There is no way that sufficient heat would pass through to ignite the diesel.

 

Bear in mind the auto-ignition temperature of diesel fuel is about 250c.

 

 

[cuthound]

11 hours ago, Mike the Boilerman said:

 

Bear in mind the auto-ignition temperature of diesel fuel is about 250c.

 

 

 

Much lower than that and variable, depending on which bit of the distillery run you test and what product preceded it.

 

It is because the flash point can be lower than 80°C that diesel comes with the Carriage of Dangerous Goods by Road regulations.

 

I know because I tried to get it exempted from the above regulations when I worked for BT (they move 1000's of litres annually topping up small standby generator tanks in remote regions).

 

When tested independently the typical flash point is above 100°C but because the fuel companies put the lower level on their data sheets it was impossible to change the CDGR regulations.

 

From Wikipedia.

 

"To ignite, the fuel must have a low flash point, but in order to avoid preignition caused by residual heat in a hot combustion chamber, the fuel must have a high autoignition temperature. Diesel 

fuel flash points vary between 52 and 96 °C (126 and 205 °F). Diesel is suitable for use in a compression-ignition engine."

 

 

Edited June 5, 2019 by cuthound
Spillung

[Alan de Enfield]

3 minutes ago, cuthound said:

It is because the flash point can be lower thsn 80°C that diezel comes with the Carriage of Dangerous Goods by Road regulations.

 

I know because i tried to get it exempted from the above regulations when I worked for BT

I thought (was told) you could move less than 1000 litres without a licence ?

 

That is why my Bowser is 'rated at' 900 litres, (but 1000 litres does fit in comfortably)

[cuthound]

5 minutes ago, Alan de Enfield said:

I thought (was told) you could move less than 1000 litres without a licence ?

 

That is why my Bowser is 'rated at' 900 litres, (but 1000 litres does fit in comfortably)

 

Transporting 200 litrs or more comes within the scope of the CDGR regs, the company must employ a Dangerous Goods Safety Advisor and the driver must hold an "ADR" endorsement to his normal driving licence.

 

http://www.hse.gov.uk/cdg/manual/adrcarriage.htm

 

[Alan de Enfield]

1 minute ago, cuthound said:

 

Transporting 200 litrs or more comes within the scope of the CDGR regs, the company must employ a Dangerous Goods Safety Advisor and the driver must hold an "ADR" endorsement to his normal driving licence.

 

http://www.hse.gov.uk/cdg/manual/adrcarriage.htm

 

Ooops !!!!!

[TheBiscuits]

6 minutes ago, Alan de Enfield said:

Ooops !!!!!

http://www.hse.gov.uk/cdg/manual/commonproblems/bowsers.htm

 

Diesel and gas oil

Diesel and gas oil (UN 1202) are in scope up to flash point 100 deg C.  Diesel/fuel oil is in TC 3, so up to 1000 litres may be carried in packages without application of much of the regulations (small load exemption).  

 Authorisation No 1   allows certain bowsers (carrying UN 1202 diesel /gas oil only) to be treated as if they are IBCs. The main conditions are

• The bowser was made before 10th May 2004
• The tank must not be "permanently fixed to a motor vehicle or trailer".
• Maximum capacity 3000 litres
• Designed for mechanical handling
• It shall remain "safe and suitable"

The significance of this is that the bowser can be treated as a package and labelled accordingly, and that if it does not carry more than 1000 litres the small load exemptions apply.

 

 

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/527033/dangerous-goods-guidance-note-23.pdf

 

Carriage of diesel (UN 1202)

 

Diesel is assigned to Transport Category 3 in ADR, which permits carriage of up to 1,000 litres in UN-approved packages per transport unit (a motor vehicle with or without an attached trailer) without most of the CDG 2009 applying (see sub-section 1.1.3.6 of ADR).

 

What is required:

• compliance with the packaging requirements (see ADR Part 4). In particular, diesel must be carried in a suitable UN approved packaging, for example in UN approved jerrycans or drums;

• vehicle will need to be equipped with one portable 2kg fire extinguisher (ADR 8.1.4.2); and

• driver will be required to undertake basic training as in ADR 1.3.

[Alan de Enfield]

 

Phew - a bit of research on the HSE website reveals :

 

Diesel and gas oil

Diesel and gas oil (UN 1202) are in scope up to flash point 100 deg C.  Diesel/fuel oil is in TC 3, so up to 1000 litres may be carried in packages without application of much of the regulations (small load exemption).  

 Authorisation No 1 allows certain bowsers (carrying UN 1202 diesel /gas oil only) to be treated as if they are IBCs. The main conditions are

• The bowser was made before 10th May 2004
• The tank must not be "permanently fixed to a motor vehicle or trailer".
• Maximum capacity 3000 litres
• Designed for mechanical handling
• It shall remain "safe and suitable"

The significance of this is that the bowser can be treated as a package and labelled accordingly, and that if it does not carry more than 1000 litres the small load exemptions apply.

There are many types of  bowser which are certified as IBCs, and  they may look like "tanks" so care needs to be taken in deciding what rules apply.  If the bowser is a properly certified IBC it can be used to carry kerosene (inc jet fuel) and be treated as package.

In all other respects carriers of diesel are now subject to the standard ADR and CDG Regulations requirements.  

 

Need to do a bit of reading on the 'small load exemptions'.

 

Edit to add : Thanks - Biscuits - found it at the same time as you did.

Edited June 5, 2019 by Alan de Enfield

[MtB]

35 minutes ago, cuthound said:

Much lower than that and variable, depending on which bit of the distillery run you test and what product preceded it.

 

It is because the flash point can be lower than 80°C that diesel comes with the Carriage of Dangerous Goods by Road regulations.

 

 

Lets not confuse auto-ignition temperature with flashpoint temperature. I chose my words carefully!

 

"The flash point is sometimes confused with the autoignition temperature, the temperature that results in spontaneous autoignition."

 

https://en.wikipedia.org/wiki/Flash_point

 

 

 

[cuthound]

7 minutes ago, Mike the Boilerman said:

 

 

Lets not confuse auto-ignition temperature with flashpoint temperature. I chose my words carefully!

 

"The flash point is sometimes confused with the autoignition temperature, the temperature that results in spontaneous autoignition."

 

https://en.wikipedia.org/wiki/Flash_point

 

 

 

 

Fair point, but when welding on the top of a partially filled tank with a vent won't the vapours ignite at the flash point?

[MtB]

2 minutes ago, cuthound said:

 

Fair point, but when welding on the top of a partially filled tank with a vent won't the vapours ignite at the flash point?

 

 

I thought about that, and decided as the tank heats up the auto-ignition temperature is the relevant value. Flashpoint requires a source of ignition -  flame, spark etc. 

 

An orange glowing spot on the inside of the tank from the weld might be classed as an ignition source, but to get there the surface temp has to pass through auto-ignition temperature. The thing preventing auto-ignition is the % concentration of vapour in air being outside the explosive limits, which is where the risk lies. The welder cannot know what it is and is taking a chance. 

 

[TheBiscuits]

27 minutes ago, Alan de Enfield said:

Thanks - Biscuits - found it at the same time as you did.

Note that Authorisation 1 expired last month!  9th May 2019 to be specific.

 

You still get the small loads exemption on your 900L bowser, but a larger one would no longer comply.

[cuthound]

44 minutes ago, Alan de Enfield said:

 

Phew - a bit of research on the HSE website reveals :

 

Diesel and gas oil

Diesel and gas oil (UN 1202) are in scope up to flash point 100 deg C.  Diesel/fuel oil is in TC 3, so up to 1000 litres may be carried in packages without application of much of the regulations (small load exemption).  

 Authorisation No 1 allows certain bowsers (carrying UN 1202 diesel /gas oil only) to be treated as if they are IBCs. The main conditions are

• The bowser was made before 10th May 2004
• The tank must not be "permanently fixed to a motor vehicle or trailer".
• Maximum capacity 3000 litres
• Designed for mechanical handling
• It shall remain "safe and suitable"

The significance of this is that the bowser can be treated as a package and labelled accordingly, and that if it does not carry more than 1000 litres the small load exemptions apply.

There are many types of  bowser which are certified as IBCs, and  they may look like "tanks" so care needs to be taken in deciding what rules apply.  If the bowser is a properly certified IBC it can be used to carry kerosene (inc jet fuel) and be treated as package.

In all other respects carriers of diesel are now subject to the standard ADR and CDG Regulations requirements.  

 

Need to do a bit of reading on the 'small load exemptions'.

 

Edit to add : Thanks - Biscuits - found it at the same time as you did.

 

Looks like they have eased the regs since I was involved circa 2000 when the CDGR regs were being formulated.

 

What happens when all if the older pre 2004 bowsers have disappeared? Presumably companies will have to use IBC based browsers. 

Edited June 5, 2019 by cuthound
Clarification

[RAB]

Not totally sure of the vagaries associated with tank explosions and flash point / auto ignition temperatures except to say in my old industry I can remember 2 or 3 explosions associated with vented oil tanks where people were killed or seriously injured due to explosions. Non involved a direct flame and one was definitely due to external welding. Baring in mind, if I remember correctly Vg46 oil has a flash point of around 200 deg C, well above diesel. I personally would not weld a diesel tank without purging it with an inert gas, but if a yard is happy to do it (many do), then so be it. I would leave the boat with them and wander off, out the way!!!!!!!

Edited June 5, 2019 by RAB

[Captain Fizz]

If I am welding on a diesel tank, I will use my mig welder.

I have two outlets on the gas regulator one of which feeds the welding torch and the other allows me to flood any airspace within the tank with inert gas.

[Phoenix_V]

https://www.facebook.com/machinesareinsane/videos/840106146321835/

[Chewbacka]

2 hours ago, Phoenix_V said:

https://www.facebook.com/machinesareinsane/videos/840106146321835/

Don't do Facebook so can't see it.  Not too disappointed though.

On 05/06/2019 at 10:04, RAB said:

Not totally sure of the vagaries associated with tank explosions and flash point / auto ignition temperatures except to say in my old industry I can remember 2 or 3 explosions associated with vented oil tanks where people were killed or seriously injured due to explosions. Non involved a direct flame and one was definitely due to external welding. Baring in mind, if I remember correctly Vg46 oil has a flash point of around 200 deg C, well above diesel. I personally would not weld a diesel tank without purging it with an inert gas, but if a yard is happy to do it (many do), then so be it. I would leave the boat with them and wander off, out the way!!!!!!!

........and make sure somebodies insurance covers the boat in case it turns into a fireball...........................

[MtB]

12 hours ago, Chewbacka said:

........and make sure somebodies insurance covers the boat in case it turns into a fireball...........................

 

Which to be fair, has never happened yet. Plenty of evidence of non NB tanks exploding but never a narrow boat fuel tank as far as I know. 

 

The fact that is regularly done with no serious explosions so far do not mean it is safe.50 years ago it was normal practice to trace gas leaks with a lighter or match. That was stopped in the end due to the occasional bad accident despite millions of leaks successfully found and fixed that way.