Gas Line

NewToy · Feb 23, 2006

My father- in -law was telling me of hitting a gas line with a dozer. The dozer got a sniff of that natural gas and it was off to the races. He said that thing was screaming like crazy and he couldn't get it shut off. He finally crossed it into some fresh air and things returned to normal. He said that was quite a ride.

John

Egon · Feb 23, 2006

That has happened more than once! /forums/images/graemlins/grin.gif

Most places now require positive air shutoff for diesel engines when operating in an environment that could contain combustible gasses.

Egon

markct · Feb 23, 2006

the only way to shutoff a diesel that has run away like that is by cutting the air flow to the engine, equipment working in areas where gas lines etc are present are often required to have a shutoff slidegate, much like an rv waste valve, in the intake line

kubotaman68 · Feb 24, 2006

I had a 475 detroit runaway like that had to knock the fuel nozel off with a hammer emergency shutoff came off in my hand. un cool ! /forums/images/graemlins/mad.gif /forums/images/graemlins/ooo.gif

NewToy · Feb 24, 2006

I had never heard of anything like that before. Around here it's not uncommon for folks to have their own natural gas well. I wish I had one in the backyard.

John

JSUnlimited · Feb 25, 2006

One other way, is to discharge a dry chemical fire extinguisher into the intake. It's a last resort as the engine will be trashed after! /forums/images/graemlins/blush.gif

markct · Feb 26, 2006

( I had a 475 detroit runaway like that had to knock the fuel nozel off with a hammer emergency shutoff came off in my hand. un cool !

)

if the engine was running away from gas in the air, then cutting off the fuel supply by your method would have had no affect on it, the only way to stop it would be to block off the air intake, or as someone else said to shoot a fire extinguisher into the engine, altho i dont see why you would want to do that since it would probably cause engine damage

Soundguy · Feb 26, 2006

When our mechanic rebuilds a diesel, on it's first start he stands ready with a big choke plate if needed.. etc..

Soundguy

Egon · Feb 26, 2006

Usually when a diesel "Runs Away" from exlosive vapours in the air it's to late for the engine and operator! /forums/images/graemlins/frown.gif

Egon

IslandTractor · Feb 27, 2006

Wouldn't a compression release lever stop a runaway engine? I have one on my Yanmar marine diesel as it is the normal way to stop the engine. If so, why don't more tractors have the simple compression release systems?

Egon · Feb 27, 2006

The chances of a compression releif stopping a diesel being fed lots of combustible vapours is pretty slim.

Egon /forums/images/graemlins/grin.gif

kubotaman68 · Feb 27, 2006

it was not from natural gas it was from the throttle going by the stop and running away but you are right once they get a whiff of gas they are history

Soundguy · Feb 27, 2006

Wouldn't a compression release lever stop a runaway engine? I have one on my Yanmar marine diesel as it is the normal way to stop the engine. If so, why don't more tractors have the simple compression release systems?


You must hate that thing huh? /forums/images/graemlins/confused.gif... Kinda like beating a child to make it stop crying... they both work.. but not the best way to go about acheiving the desired results.... I've never heard of using comp release as the 'usual' way to stop a diesel.. rather fuel stop valves.. etc... All my diesels have printed in the manual that using comp release to kill the engine will... kill the engine... as it washes the cyls down with unburnt fuel.. this reduces lube on cyl walls.. and leads to fuel dilution of crankcase oil.. lowering lube in the whole engine...

Guess yours could be some special case.. but sounds alien to me.. unless for emergency.. etc..

Soundguy

Soundguy · Feb 27, 2006

( The chances of a compression releif stopping a diesel being fed lots of combustible vapours is pretty slim. )

Why? Even if the fuel simply 'cooks' off from the heat.. with the valves lifted open.. there won't be compression for that compression engine to fire with.. If the fuel-air charge cooke doff.. the path of least ressitance is the open valve.. not the piston???

Soundguy

SnowRidge · Feb 27, 2006

I watched mechanics trying to stop a run away diesel when I was in the military. They tried everything, including the compression release. Nothing worked. The engine lunched itself.

Egon · Feb 27, 2006

Easiest way is to find out is to try it! /forums/images/graemlins/grin.gif

Get the diesel warmed up, Open up a propane bottle into the the air intake and then pull the compression realease.

Let us know what happened! /forums/images/graemlins/grin.gif

Egon /forums/images/graemlins/grin.gif

markct · Feb 27, 2006

( Usually when a diesel "Runs Away" from exlosive vapours in the air it's to late for the engine and operator! )

i have to dissagree, i have seen diesels rev up very high, not totaly run away, but increase rpms very fast, from just a little bit of brake cleaner used nearby, i think that on a concentration that would cause no imediate harm to the operator that the engine would still breath alot in

Egon · Feb 28, 2006

Sorry about the lack of proper information.

I was refering to a situation in which there is a lot of combustible vapour; such as in when a natural gas line is hit. In these cases there is often a big bang associated as the vapour cloud explodes. This has happened more than one or two times. Other times a motorized unit may drive into a vapour cloud from a leaking line or ?? Lots of other type senarios.

Egon /forums/images/graemlins/grin.gif