Fume Guards at Gas Pumps

No if they are properely made the vapor is captured. Modern cars like the prius also capture the vapors as long as the nozzle is inserted properely, so the guards don't do anything here, but do make a difference with older cars.

 

It gets pulled back into the pump.

Tom

 

in older cars, the vapors are captured in a charcoal filter, and the vapors are then sent to the engine to burn. I assume that the vapors at the gas station are recaptured into the tank and pump system.

Evaporated gasoline vapors were and I suppose still are a leading cause of smog.

Icarus

 

^ There's a typo there, obviously, but I cannot figure out what you intended to say.

 

It is only released back into the atmosphere after being successfully pumped into a vehicle and burned.

The vapour gets pulled back into the tank, to try and get put into another vehicle another time. Eventually it will succeed and be burnt.

 

It is supposed to go back into the head space of the storage tank as the liquid gasoline is being pumped out.

See Figure 5.2-7 of this EPA document (AP-42)...

http://www.epa.gov/ttn/chief/ap42/ch05/final/c05s02.pdf

 

Hope this helps
Gasoline Vapor Recovery from Fuel Pumps Using MTR Membrane Process - Membrane Technology and Research, Inc.

But more and more these systems do little because new cars have their own vapor recovery system.

 

I'd guess 'other' to be an autocorrect of 'to the'. I fixed the typos I could see at first glance. Icarus, please correct me if I'm wrong.


"In older cars, the vapours are captured in a charcoal filter, and the vapours are then sent to the engine to burn. I assume that the vapours at the gas station are recaptured into the tank and pump system.

Evaporated gasoline vapours were (and I suppose still are) a leading cause of smog."

 

I pad is a great toy, and a pretty good toy. The auto correct is pretty cool, but it come up with some funky stuff. I was never a very good proof reader,, and this has only made it worse. I often post in haste, and have to run so I don't always read,, and then the posts threads have moved on.. thanks for pointing out the errors,,, and fixing them.

Icarus

 

Thankfully - or maybe not - I'm a pretty good proofreader. Autocorrect (autotypo?) would drive me insane. I've never met a spellchecker I liked and refuse to use them, mostly because I insist on Canadian spellings, which typically fall somewhere between British and American. Newspapers seem to have given up, and just hand the whole writing process over to computers. Most of the words are spelled correctly, but the right words aren't necessarily in the right places.

 

I am a poor typist. I have lots of typos. I let the spell checker point out possible errors, but I proofread every post and typically have to make one or two corrections after clicking on "Preview Post." I do not use auto-correct because it's a frustrating piece of crap that insists on making changes I don't want.

 

Sadly, while living in FL (for way too long) I would not have known what a fuel guard was; it's a rare find there.

 

I will endeavor to do a better job of proovewreading in futur.

Icarus

Statring know.

PS I do have a hard time proof reading on a screen!

 

It's the other way around.. newer cars have ORVR which is the charcoal filter. Older cars have no onboard refueling vapor system and that's why Stage II was installed at gas stations since that could be done quickly while ORVR was designed and implemented (both requirements come from CAA90).

ORVR penetration has reached the point where EPA expects that Stage II will no longer be required sometime in 2013. However some states may keep it as a requirement since it would still control non-ORVR vehicles (older than ~1999 for cars, and ~2004 for trucks.. the requirements were phased in so there's no exact dates). There is a potential compatibility issue with some Stage II systems and ORVR, though.

Stage II doesn't always have a condenser.. the tank may just vent to atmosphere (maybe via a conservation vent), depending on regulatory requirements. There is still an emission reduction effect because the vapor returned to the station tank is partially saturated with gasoline, so less gasoline evaporates from the liquid surface into the headspace compared to non-Stage II operations. This is where the compatibility issue comes up.. if ORVR controls the loading emissions from the vehicle tank, then it's just air going back to the tank and evaporation could potentially increase. I tend to think this is a bit overblown by station operators eager to shutdown their Stage II systems.. because let's say you have ORVR and no Stage II.. you're still going to pull air into the tank to balance (collapsed tanks are no fun) and so that evaporation is going to happen either way. I'd tend to think the reduced efficiency of ORVR+StageII would be offset by non-ORVR vehicles continuing to be controlled by Stage II (vs. nothing).

 

Thanks, I couldn't remember the dates. Certainly there are many pre 2004 trucks out there, but they will be at least 10 years old when the law ends.

I didn't realize some stage II tanks didn't have condensers. Is this a problem with temperature fluctuation, or do the tanks have membranes that allow air out and keep fuel in like those with condensers.

 

Years ago, there was a (now-defunct) chat board where several of the regulars maintained aliases. One of these guys, for one of his aliases, would type as carelessly as he could. Some who didn't recognize the ploy thought it was just a very stupid person, but the cogency of his comments belied his feigned spelling incompetence. It was an interesting site. There was no moderation. You could say anything you liked, and have as many aliases as you wanted. There was at least one identity that was shared by several people, each of whom would post to it as they saw fit, so that this identity would argue with itself.

 

I don't have to feign poor spelling, it comes very naturally. I am a really great typist too. I can type 200 wpm,, with 19 errors however. Computer has made it easier however. My Jr Highschool typing teacher would roll over in her grave,, as striking over was a big taboo,,, not any more!

Icarus