Date: Wed, 10 Sep 2008 15:24:33 -0400
Reply-To: List Moderator <ecgrants**At_Symbol_Here**UVM.EDU>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: List Moderator <ecgrants**At_Symbol_Here**UVM.EDU>
Subject: Re: Anyone familiar with gas station pump hazards?

A reply to a question from last week...

 >I had a phone call from someone who was injured at a self-service  
gas pump in rural Georgia... The end of the hose attached to the pump  

flew off and hit her on the head.  She was sprayed with gas, and  
suffered ongoing medical issues from the impact with her left eye.

	From: 	sstepenuck**At_Symbol_Here**
	Subject: 	Anyone familiar with...
	Date: 	September 9, 2008 5:18:15 PM EDT (CA)

I forwarded that email to my kids and to one of my cousins who has  
much experience in industry.
Here, with a couple of minor grammatical mistakes corrected, and with  

full disclaimers on my and his part, is his reply:

I do suspect urban legend here or at least some incorrect facts. I've  

worked around fuel dispensing equipment all my life and never heard of  

such a thing.

Most modern fuel pumps aren't really pumps, they=92re only metering  
dispensers because the actual pump is in the underground tank. So for  

technical accuracy, I will use the word "dispenser" as opposed to  
"pump" even though we all know them as pumps.

Most modern dispensers have an overhead manifold with a hose  
attachment fitting sticking through an opening in the overhead sheet  
metal. =46rom that fitting hangs a very short piece of hose which ends  

with a "break-away" coupler. =46rom the break-away coupler there is  
usually the longer hose with nozzle.

The purpose of the break-away coupler is for the nitwit who drives  
away with the nozzle still in the car. The break-away is designed to  
be the weakest link in the hose assembly so that it will part first  
when faced with the tension created by a departing car. Even so, it  
takes a fair amount of force to cause a break away. Most people could  

not part one simply by yanking because they are not strong enough. The  

break-away has an internal valve which will slam shut in the event it  

is parted. They are quite reliable and are rigorously tested and they  

immediately stop all fuel flow. There might be a momentary "psst" of  
fuel but no great wide-open spraying like you might have with a garden  

hose nozzle. They are similar in design to quick-disconnect couplers  
used on pneumatic tools.

Even if the valve failed and caused the short hose with the break-away  

to whip around wildly, keep in mind that length is very short and the  

height is well above any normal person's head. Also most systems  
operate a much lower pressures that claimed in the e-mail.

Consider this: Everybody has played with a garden hose. The average  
garden hose operates at typical water main pressure of 35 to 80 PSI  
and even at that pressure the hose would blow itself out of the filler  

pipe if you weren't forcibly holding it in. Imagine a fuel nozzle at  
150 PSI! It would take at least two rugged firefighters simply to hold  

the nozzle into the filler on your fender. That vision alone puts the  

lie to this story. If you stuck a 150 psi nozzle into an empty "jerry  

jug" setting on the ground and pulled the trigger, the jug would be  
blown clean across the parking lot assuming you weren't knocked to the  

ground by the reactive thrust.

I suppose there is the possibility that a break-away coupler could  
just spontaneously part and the hose would fall to the ground. If you  

were standing directly under it you might be hit in the head but it  
would be by the force due to gravity because the pump pressure would  
be contained in the short portion still attached to the dispenser. It  

would seem to me that only two scenarios that could cause a  
spontaneous break-away are an incorrectly installed break-away coupler  

that wasn't tested, i.e. the two haves weren't fully inserted together  

and latched or a damaged break-away coupler that just experienced an  
incomplete break-away caused by a departing nitwit. Keep in mind that  

the second scenario would require the next customer to have to pick up  

the nozzle from the ground because that's where it would be laying  
since the nitwit drove away.

Unless I'm missing something here, I just can't buy this story as it's  

written. I'm not writing it off entirely but it needs much more  
detailed specifics. One thing is for sure, they aren't commonplace as  

suggested in the e-mail. Also OSHA would cover any event at a full- 
serve station where the operator is an employee. This would also be  
true at non-public fleet fueling station. Even at the public self- 
serve stations, any event that occurred while the employees were  
servicing or testing the coupler would be covered by OSHA.


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