In Friday's opening segment, Rachel talked about changing regulations to do with gas pump nozzles and vapor recovery.
From the transcript:
But now, because auto manufacturers are taking account of it, they are taking care of that problem inside the car. They have rebuilt gas tanks so the gas tanks themselves, in the car, actually deal with most of the problem. Because of that, those big, black, plastic, rubbery hood things that go over the gas pump nozzle ... are going to go away.
Like Ms. Jacobson above, I figured vapor recovery was all about the gas coming out of the pump and didn't see how a change in the tank (Rachel didn't actually say "engine" but I think we're on the same page) would help anything. After digging around a little I have a new idea of what the answer is, but I'm going to need some help from any motorheads out there who know for sure.
The EPA site has a lot of explanation of the regulations (including implementation dates that make clear why the regulation is changing now), but not so much about the mechanics. Presumably that was left up to the individual car makers.
I got this diagram of an On-board Refueling Vapor Recovery System from a Subaru Impreza discussion forum:
I added the color to show where the gas is. For me, adding the color helped me realize what's not in color. That is to say, where there's no gasoline in the tank, that empty space is fuel vapor. "Running on fumes," right? When you fill the tank, all of that air has to be displaced to somewhere else. I'm guessing (this is where I need help) that on old model gas tanks, that displaced air came right out the pump hole. Putting the sleeve on the nozzle so that it covers the hole would catch the vapor being displaced by the fuel. Not a bad idea if you consider how many empty gallons are replaced on any given day in the U.S.
From what I can tell, that recovered vapor was sucked back into the big tank under the gas station to replace the liquid fuel being pumped into your vehicle. See the diagram to the right.
Before I digress to gas pump design, let's go back to that Subaru gas tank diagram. Way over on the left (1) is labeled "canister." I'm not clear on the chemistry, but it has activated charcoal in it that somehow cleans that vapor. Depending on the system, the cleaned (but probably still at least a little fuelly) air can be sent into the engine's air intake system.
The rest is a network of valves, vents and pressure sensors to make sure nothing goes down the wrong tube and everything flows in the right direction. (Fuel vapor under high pressure will combust, so there's probably something in the design to make sure that doesn't happen, for example.)
So there you go. With the tank reprocessing the displaced air when the tank is filled, there's less displaced vapor coming out at the input.
Just one more thing about gas nozzles that I didn't realize that maybe you'll find interesting. That pipe that you stick into your car is actually a tube within a tube. The way the no-longer-required sleeve worked was that while fuel was coming out of one tube, another tube was sucking out the vapor. Even without the sleeve, I think that's still the case. Y'know those holes around the outside at the end of the nozzle? That's for vapor capture.
While poking around I found this eBay listing for gas pump parts, which lists one vapor recovery hose. I'm pretty sure the "send" and "return" are what we're seeing in the cross-section image here:
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Darn. I like those rubber boots. It makes the nozzle easier to handle in the winter when they get <em>cold.</em>
You basically got it right, Will. The actual system design varies by car but they all essentially function the same way.
Just to give you an idea how old a car has to be to NOT have the vapor capture system, my 99 Nissan Pathfinder has one, and that model of car had them designed in back in 96.
Viewer watches a news story. Asks questions and the result is research and a blog post with links and diagrams.
Liberals.
That's pretty much how it goes.
That's quite a compliment. You're actually highlighting an intelligent and rational approach to learning, something that many who like to drink Tea just don't get, or so it seems.
How about we just appreciate the explanation without politicizing (and making fools of ourselves in the process)?
I'm a comedian, I don't mind making a fool out of myself.
Just a little different.
Are the nanotube oil sponges the real thing? Could they also be used to clean up under old service stations so that the land could be used again? The Gulf etc.?
Dang it all ! Name that tune, I keep trying but all I come up with is "it's a ga,gas,gas..."
AHA! Jumping Jack Flash-thanks Bing.
The next question is "What regulation drove the auto manufacturers to design that system?
I would bet money they didn't just do it because it was good for the environment.
Thank you regulators, we can all breathe a bit easier now.
I recall it was the smog problem in California. Once implemented and proven there it was rolled out nationwide.
The diagram is not very accurate. Unless the car has been sitting for a year or there's some defect with the fuel system, there will always be fuel in the fuel line from the fuel tank to the fuel rail. There is something called a fuel pressure regulator (either at the fuel pump in tank) or at the fuel rail that ensures there's almost instantaneous fuel at the fuel injectors when you crank the engine (ie switch to "start.") Fuel pressure is maintained at least for awhile. Think about it, your car (if functioning properly) starts immediately you crank the engine. There is no way it would be able to do so if the lines as shown in the diagram only had vapor. It takes time to activate the relay, which then kicks on the fuel pump that is in the tank, and then the pump to pump enough fuel to the fuel rail (and injectors) maintain adequate fuel pressure for the car to start and run. Most of these EVAP systems have been awhile for at least a couple decades. There are normally two standards. Federal and California (CARB) with the latter being the most stringent.
The author of the article noted that he added the color to the fuel line diagram. Before hand it was all in black and white, presumably.
Seeing as how the writer professed to not being an expert, and noted how little he knew overall, I don't think criticism is really necessary.
Your comment is rather informative, but it doesn't seem you read the article entirely.
The direct fuel supply lines are separate from the recovery lines and not shown on the drawing.
Hey, Steve am I in Gearhead heaven? I think Tim the toolman is waiting patiently around the corner for his chance to say something. I think we could infiltrate the carburetor to extinguish less fumes per capita depending on the size of the motor we might have to adjust the Finnigan pin, do we really need all those spark plugs? Boy, you're gonna need some kind of callobarated wrench to get under those new fandangled engines. Just replace your head gaskets. That oughta work.
Rachel, the pump and on-board vapor recovery systems are for 2 different purposes. As you fill your tank, the fuel forces out the fumes through the filler neck. You'll hear a suction fan running in the gas pump drawing those fumes through the boot on the nozzle, through the pump hose as you show in your "Typical Stage II Vapor Recovery" diagram, and back through the pump.
In the past, cars' gas caps were vented. As you emptied the tank by driving, air was drawn through the vented cap so a vacuum wouldn't form and cause the tank to collapse. However, on a hot day, the fuel and fumes in the tank would expand. To keep the tank from bursting, the nasty fumes would exit through the vented cap and pollute the air.
The system shown in the Subaru diagram addresses these problems with a non-vented gas cap (not shown). As you drive, valves allow air in but keep vapors from leaving. If the fuel and fumes expand on a hot day, the fumes are stored in the charcoal canister. When the engine is running, those fumes are sucked into the engine and burned.
This has no effect at all when the engine is off and you are filling your tank. The fumes are still forced out through the filler neck. If that boot is taken off of that nozzle, those fumes will pollute the air just like they used to.
Unburned natural gas is a serious pollutant, but unburned gasoline is worse. This is a bad place to deregulate. I don't expect it to have any effect on the pump price, either.
There are three basic different "systems" ; the old system that literally pumped more than enough gas to the fuel delivery system; TBI's, TPI's and Carburetors, then along came fuel injection and they had what's called a bypass system which supplies enough pressure to run the fuel injectors. Then along came "no return" systems which was kinda like the original systems but incorporated a fuel pressure regulator system which told the cars' PCM or ECM how much fuel pressure to be delivered at any given moment. There really is no difference to your fuel economy, this is all about how much fuel via 'vapor' the oil industry can get back from your car. The amount is nominal, you'll never feel it in your pocket. But on an aggregate scale times hundreds of thousands of cars they do make a profit. As a car owner there are a couple things you SHOULD do every 30,000 miles or so to keep your car running right. Replace the spark plug wires and spark plugs. The new platinum or Iridium plugs last up to 100,000 miles, oil changes; every 5,000 miles for organic oil, every 15,000 miles for synthetic oil. DEX-Cool and others every 50,000 miles. If you have the green antifreeze then its every 30.000 miles. You would be surprised to know that if your thermostat is not working it will throw your transmission into a tizzy. Or your MAF sensor (mass air flow sensor) is dirty it will also screw up every other system in your car. I suggest you stick to your manufacturers suggested service manual regarding regular maintenance. You'd be surprised how many cars i have to fix because of lack of routine regular maintenance. And these "fixes' cost hundreds of dollars. EVAP Canisters, fuel pressure regulators, Idle Air Control Motors or Mass Air Flow sensors just because the air filter wasn't replaced on a regular basis. Or driving a MAF sensor without it being cleaned or spark plug replacement or dirty oil Oil changes must be done at the most every 5,000 miles period. It will @!$%# up your engine which will cost you thousands or a new car.
"Putting the sleeve on the nozzle so that it covers the hole would catch the vapor being displaced by the fuel." Partly true. As you know fluids flow the route of least resistance. Air and gasoline fumes do this too. If you did not have the 'sleeve' air and fumes would travel though the hole, but with it acting just like a stopper it does not.
"From what I can tell, that recovered vapor was sucked back into the big tank under the gas station to replace the liquid fuel being pumped into your vehicle. " Not so much suck as blow. The gasoline being put into the car displaces the air and fumes. This air and fumes are what the EPA has been worried about and having gas and car companies fixing. Gas companies used this air and fumes to replace the gasoline in the big gasoline tank.
The best fix to all of this is an Electric Car.
Volvo started using a similar system back in the 80s.
Wow, this is right up your alley. Dear Lord Volvo, what are your thoughts about golf carts being used by people who just need to go around the corner for a few groceries? They could make a separate lane for the golf carts and we could even deck them out with Rubber Baby Buggy Bumpers and play a good old fashioned game of Bumper cars or have certain stops along the way designed for letting your Bumper cars play with each other. Little Bumper car playgrounds. Cool. I would go.
Angel, there is a place where they already do this. It is called The Villages, near Lady Lake, FL. Retirement community of about 100,000, golf cart trails everywhere, three downtown areas all accessible by golf cart. No bumper car games, but they do have a very impressive golf cart drill team. Search YouTube for The Villages Golf Carts, its fun to watch...
I drive an electric car. No gas tank, no oil changes. This whole discussion sounds like Greek to me.
Two types of Stage II vapor recovery systems are used in the USA; the balance system (the one with the large boots on the ends of the nozzle) and the vacuum assisted system (the nozzle appears to be a conventional nozzle). The elimination of Stage II vapor recovery means that people who own cars without ORVR canisters (about 30% of the vehicle fleet as of 2013) will earn the right to inhale and ingest toxic vapors such as benzene, a known carcinogen. This also means that if you are refueling your 2012 BMW next to a person who owns an older vehicle (without an ORVR canister); you will also share in the ingestion of toxic benzene vapor. The adverse health impacts of this action by US EPA and Cass Sunstein run counter to the objective of eliminating outdated regulations while at the same time protecting public health and the environment. A shameful example of politics trumping science, engineering and logic. Moreover, a small company which has developed a robust and commercially proven enhancement to Stage II vapor recovery has installed over 500 such systems worldwide. Their Permeator system reduces emissions, saves fuel, improves public health, and reduces the chance for groundwater contamination at gas station sites. They have made formal comments to US EPA and other State Agencies, but their inputs have been largely overlooked for the past 8 years. Very disappointing situation.
For twenty years I worked are a mechanic on gas powered equipment. My brother was as good a mechanic as I ,but he got off track and chose philosophy as a minor. It changed him. Proof, my brother had just come back from college as I am having a problem with the fuel delivery system in repair , so I remove the fuel line at the carburetor and put the open fuel line in my mouth and suck a big chuck of crude out and then spite the mouth full aside, reattach the line and start the engine, fixed. He freaks out !! " Man Don’t Do That !!" ,he says as he comforts me. Now you have to understand, he had taught me how to clear a line that very same way, just before he went to school.!! . . . just saying . . .
Just be glad you don’t have to clamp a static conductor strap to your behind before you gas up. Causes I think that would be a very good idea. Less gas refueling fires !!
The last question is, Why not just use a fully sealed system like NASCAR is using. Just don’t over fill it.
hey you guys. theres another more cheaper way to get rid of harmful toxic fumes. Switch to a reneweable biofuel. hemp or algea anyone?
Ohio State University in the 1970's was working on using algae as a natural battery. Gives new meaning to Shockingly Green. yes ?!? Porbably mostly for space travel stuff. Wonder how far they got ??
That would be great... if we didn't have the fossil fuels lobby controlling over half the government. As it is, not likely.
Didn't old Neil write a song about OHIO? It was concerning a shooting that occured there amongst young protestors who were against the Vietnam war. Hmm, perhaps they were after the secret formula instead.
Losing the slinky tube from our gas pump handles
OK. Rachel’s point is probably that regulations are only good so long as they make sense. And that we can improve them if times get better. Just like those goofy kids down on Wall Street need a little guidance and control. And if they ever grow up . . .well, first things first. . Elisabeth Warren can explain that better than I.
Now for some serious car stuff ( the following is for real gear heads only ). Now that milk cost no more than gasoline, I have begun designing an engine that runs on milk. So far it seems, the engine may be lactose intolerant and the darn milk keeps spoiling in the tank. Also , nearly every morning I have to clear all the neighborhood cats off my car before leaving for work. Still better than the results I got trying to use navy beans as a fuel in last proto-type. That blew the heads right off the engine.
Disclaimer: I did not really try to make an engine run on milk. But now that I consider it, navy beans should not be written off so quickly as a power source. How about space exploration. A bunch of lumberjacks tied to the side of a space ship having just been fed double helpings of navy bean soup and the next report to the ship's Captain is, “ Sir, we have just increased in speed by 500 kilometers per hour !!” . . .or not . . .
We can fly, we can fly.
We can fly, we can fly.Doc has nothing on you. Can you synchronize your flight to the year 1963. I have some investigating to do. I will mail you the tape which will then self implode. Mission accomplished. Go young man, where no man has ever gone before, Back to the future. Meantime, back on the farm, I will be milking some more cows for future missions from Gad. Teamwork, teamwork now if we can get the rest of the planet on board we'll be okay. Fly backwards young man.
You may also get a discount if you take a defensive driving course. If there is a young driver on the policy who is a good student, has taken a drivers education course or is at a college out of the area without a car, you may also qualify for a lower rate. search online for "Clearance Auto" they are the best for student drivers
I wonder if this affects fuel efficiency as well. It wouldn't be by much (~ <1% would be my guess) but with increasing efficiency standards it would help.
I imagine the EPA's motive for the regulation though is decreasing VOCs (like gasoline vapor) which contribute to smog.
So, where can we go to get our gas tanks replaced for free? Should we take our cars to the car dealer mechanics? I assume that they will still keep the plastic arms on the gas pumps until everyone has had the gas tanks replaced for free, am I right? I mean it just wouldn't make sense otherwise, because most cars probably don't have the new gas tanks. Can the old gas tanks just be refurbished to qualify as non-pollutant?
Unless your car is 1996 or older, it's not an issue. That was Rachel's point.
The gas pumps were easier to retrofit than all of the old cars on the road back then. The on-board system is better because it handles both the displaced fumes upon filling, and managing vapor pressure in the tank as the temperature changes.
The gas pump hoses won't disappear overnight. Stations will now have the option of replacing them with cheaper, simpler hoses, but that won't happen until the ones they have need replacing.