Fire in diesel hose

[zkhan1978]

Dear all,

three disel generators (110kv) were connected with a external disel tank (metal) through hoses (was protected with metal mesh). as generated started after 2-3 minutes, fire caught in hose pipes. can please any one tell me , what may be the cause of fire..........

zabiullah

 

[augie47]

zabiullah
Welcome for the forum.
There are a number of highly intelligent and knowledgable folks who post here and hopefully one of them can give you a really good possibility.
In the meantime, the only possible answer I can think of would be in reference to improper grounding. I have seen similiar situations caused by metallic hoses attempting to carry welding currents when grounds are not relocated properly. If the generator neutral or grounds were not sized and bonded properly, I could see a situation where the hoses would try to carry current. If each generator has a properly size equipment ground connnected to a common point, that would negate my idea completely, but that would be the 1st thing I would check (from an electrical standpoint)

 

[ron]

Diesel has a relatively high flash point (higher than gasoline, etc), so look for a source of heat/ignition.

 

[jrannis]

The fuel returns hot to the tank.
Is it possible that all three units returning hot fuel could produce enough heat to cause this condition?

 

[brian john]

In the hoses? or on the hoses? Number 2 diesel?

Does not seem with returning fuel there would be enough heat and oxygen for a fire.

Check for current on the metal jackets, this might generate sufficent heat espically if there was a spark involved.

 

[zkhan1978]

Three Diesel Generators (110kv) were connected with an External Diesel Tank (metal tank) through armored(metal) hoses (external fuel lines) coated with plastic. After setting up all electrical connections, Generators started. Suddenly one DG stopped. Again it started by operator. After 10 minutes it was found that all external fuel lines(hoses) connected to Diesel tank, caught fire with smoke (without flame). Plastic cover burned.


Is there possibilities of follow of current on Hoses? if yes, how its happened?

 

[augie47]

...........................

Is there possibilities of follow of current on Hoses? if yes, how its happened?

possible ? Yes! see Post #2

 

[brian john]

I ask again in the hose or on the exterior of the hose?

 

[cschmid]

I am having a hard time here as deisel would not burn in an enviroment without air present. such as in a presurized hose. so that leads me to believe it would be a leak next to a very hot heat source such as a exhaust manifold..or it was compressed enough to cause combustion. because deisel requires an open flame to ignite or be under pressure. it would normally supress a spark..I again would like to learn here as this is a first time experience here never seen this or heard of this.

 

[wireguru]

from what the OP is saying (fire with no flames) it sounds like the hose got hot enough to make the pvc jacket on it melt and smoke. I bet there was no actual fire.

what caused the generator to shut down, and why was it restarted without finding the problem? I wonder if there was bad grounding, a fault occurred, and the steel braid on the hose carried the fault current which melted the pvc jacket and smoked as it burned up.

 

[quogueelectric]

Probably feul leaking on exhaust most likely turbocharger and inter cooler on unit.

 

[zkhan1978]

Dear Brian,

Fire was on the Exterior of the Hose, PVC jacket melted. (hoses was of metal) and covered with PVC.

thanks!

 

[hillbilly1]

I would venture to guess it was grounding issue, a fault happened using the fuel line as the return path. The generator that shut down was probally supplying the fault current. I would check grounding and look for a short to ground somewhere too.

 

[brian john]

I would venture to guess it was grounding issue, a fault happened using the fuel line as the return path. The generator that shut down was probably supplying the fault current. I would check grounding and look for a short to ground somewhere too.

Or as noted the fuel was dripping on the hose and was on fire from turbo (or other component).

Can not imagine anything else.

 

[hillbilly1]

Or as noted the fuel was dripping on the hose and was on fire from turbo (or other component).

Can not imagine anything else.

From what the OP stated in the first post it was the fuel line to the external tank smoking, but not actually on fire, did not see anything in the post about leaking fuel or flames. The braided fuel line probally made a high resistance return for the fault. Hard to say on the limited info given. (see post #2)

 

[iaov]

There have been instances of fire caused by static electricity in diesel transfer hoses. This also goes back to improper grounding and bonding.

 

[brian john]

From what the OP stated in the first post it was the fuel line to the external tank smoking, but not actually on fire, did not see anything in the post about leaking fuel or flames. The braided fuel line probally made a high resistance return for the fault. Hard to say on the limited info given. (see post #2)

Big engines leak.
But as you state unless he wants to pay my frieght to investigate it first hand this is the best we'll be able to provide that is IMO a wide choice of options.

While I agreee with you the other option, I have seen smoking floors etc...several times (not on fuel lines).

 

[cschmid]

OK long time between posts but I was inspecting our generators and maybe have a theory.without a pic or more info how about his. the fuel line is a factory made line with crimped on ends. the hose is old and the crimp on one end is slightly leaking, I mean ever so slow. as the hose dried out and became soaked with oil (diesel oil), it started to deteriorate. then the surface of the hose became volatile and started to smolder until it ran out of contaminated rubber; which made the hose have the appearance it was on fire. which in essences it was but not in the way our minds have envisioned it.