Examine individual changes

'{{Short description|Machine at a filling station that is used to pump fuels}} {{For|the automobile component|Fuel pump}} {{Use American English|date=March 2021}} {{Use dmy dates|date=March 2021}} [[File:WaynePump-sm.jpg|thumb|right|A pump, manufactured by [[Dresser Industries|Dresser Wayne]], in [[Greece]].]] [[File:Fuel dispenser in use.jpg|thumb|A gasoline pump being used at a BP [[filling station|petrol station]] in [[Wisconsin]].<ref>{{Cite web|url=https://dnr.wi.gov/topic/SmallBusiness/Resources/GasStations.html|title=Gas Stations - Wisconsin DNR|website=dnr.wi.gov|access-date=2019-06-01}}</ref>]] A '''gasoline pump''' or '''fuel dispenser''' is a machine at a [[filling station]] that is used to [[pump]] [[gasoline]] (petrol), [[diesel fuel|diesel]], or other types of liquid [[fuel]] into vehicles. Gasoline pumps are also known as <!--alpha by location-->'''bowsers''' or '''petrol bowsers''' (in [[Australia]]),<ref>{{cite journal |journal=Ozwords |url=https://andc.anu.edu.au/sites/default/files/ozwords_oct05.pdf |publisher=Australian National Dictionary Centre |date=October 2005 |author=Mark Gwynn |title=When people become words |quote=But one doesn’t have to be an Australian to enter the Australian lexicon &mdash; take bowser 'petrol pump' (in Australia), which is [[namesake|named after]] a company established by U.S. inventor and entrepreneur [[Sylvanus Bowser|S.F. Bowser]]. |access-date=2013-07-24 |archive-url=https://web.archive.org/web/20110409200400/http://andc.anu.edu.au/sites/default/files/ozwords_oct05.pdf |archive-date=2011-04-09 |url-status=dead }}</ref> '''petrol pumps''' (in [[Commonwealth of nations|Commonwealth]] countries), or '''gas pumps''' (in [[North America]]). Emoji symbol is ⛽. == History == The first gasoline pump was invented and sold by [[Sylvanus Bowser]] in [[Fort Wayne, Indiana]] on September 5, 1885,<ref>{{cite web|last=Alfred |first=Randy |url=https://www.wired.com/science/discoveries/news/2008/09/dayintech_0905 |title=Sept. 5, 1885: Pay at the Pump |publisher=Wired.com |date=2008-10-01 |access-date=2011-12-10}}</ref> pre-dating the [[automobile]] industry- It was commonly used to dispense the [[kerosene]] used in [[kerosene lamp|lamp]]s and [[Primus stove|stove]]s. He later improved upon the pump by adding safety measures, and by adding a hose to directly dispense fuel into automobiles. For a while,{{vague|date=April 2021}}{{when|date=April 2021}} the term ''bowser'' was used to refer to a vertical gasoline pump. In the United States this term is now only used for trucks that carry and dispense fuel to large aircraft at airports,{{Citation needed|date=April 2021}} but it is still used sometimes in Australia and New Zealand.<ref>{{cite news |url=http://nla.gov.au/nla.news-article259495986 |title=Fuel for thought |newspaper=[[Air Force (newspaper)|Air Force]] |volume=46 |issue=21 |date=18 November 2004 |access-date=21 February 2022 |page=4 |via=National Library of Australia}}</ref> The first gasoline pump was patented by Norwegian John J. Tokheim in 1901. The Tokheim pump was named for him. Fuel retail industry giant OPW (a Dover company) acquired Tokheim in 2016.{{Citation needed|date=April 2021}} Many early gasoline pumps had a calibrated glass cylinder on top. The desired quantity of fuel was pumped up into the cylinder as indicated by the calibration. Then the pumping was stopped and the gasoline was let out into the customer's tank by gravity. When metering pumps came into use, a small glass globe with a turbine inside replaced the measuring cylinder to show the customer that gasoline really was flowing into the tank.{{Citation needed|date=April 2021}} == Design == [[File:Hydrogen station pump.jpg|thumb|[[Hydrogen station]] pump at [[shell plc|shell]]]] [[File:Fuel Dispenser.jpg|thumb|A four pump dispenser at a petrol station in Finland. The dispenser shown here dispenses 95E10 and 98E5 petrol; diesel as well as low tax [[fuel oil]] dyed with [[Solvent Yellow 124]] (indicated as "Polttoöljy"/"Brännolja"/"MPÖ"; primarily intended for non-road vehicles such as those used in the agricultural and construction sectors)]] A modern gasoline pump is divided into two main parts&nbsp;– an electronic "head" containing an [[embedded computer]] to control the action of the pump, drive the pump's displays, and communicate to an indoor sales system; and a mechanical section which (in a self-contained unit) has an electric motor, pumping unit, meters, pulsers and valves to physically pump and control the fuel flow. In some cases the actual pump may be sealed and immersed inside the fuel tanks on a site, in which case it is known as a [[submersible pump]]. In general, submersible solutions in Europe are installed in hotter countries, where suction pumps may have problems overcoming [[cavitation]] with warm fuels or when the distance from tank to pump is longer than a suction pump can manage. In modern pumps, the major variations are in the number of hoses or grades they can dispense, the physical shape, and additional hardware for services such as [[pay at the pump]] and attendant tag readers. Light passenger vehicles pump up to about {{convert|50|L|USgal|abbr=off|lk=on}} per minute<ref name=ukcert>{{cite web |title=Certificate Pursuant to section 12 of the Weights and Measures Act 1985 |url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/296219/UK-2780-revision-3.pdf}}</ref> (the United States limits this to {{convert|10|USgal|L|abbr=off|disp=sqbr}} per minute<ref>{{cite web|url=http://www.epa.gov/oms/regs/ld-hwy/evap/spitback.txt |title=The EPA 10 gallon per minute fuel dispensing limit |publisher=U.S. Environmental Protection Agency |date=1997-09-24 |access-date=2016-04-20}}</ref>); pumps serving trucks and other large vehicles have a higher flow rate, up to {{convert|130|L|USgal|abbr=off}} per minute in the UK<ref name=ukcert/> and {{convert|40|USgal|L|abbr=off}} in the US. This flow rate is based on the diameter of the vehicle's fuel filling pipe, which limits flow to these amounts. Airline refueling can reach {{convert|1000|USgal|L|abbr=off}} per minute.<ref>{{cite web |title=How Large Aircraft Fuel Up |last=Austerman |first=Gary |date=May 1997 |publisher=Petroleum Equipment & Technology Archive |url=http://www.petrolplaza.com/technology/articles/MiZlbiYxMDIxMyYmMSYyJiY%3D}}</ref> Higher flow rates may overload the vapor recovery system in vehicles equipped with enhanced evaporative emissions controls<ref>{{cite web |title=California Refueling Emission Standards and Test Procedures for 1998 Through 2000 Model Motor Vehicles |date=August 5, 1999 |url=http://www.arb.ca.gov/msprog/evap/orvr00.pdf}}</ref> (required since 1996 in the US), causing excess vapor emissions, and may present a safety hazard. Historically, gasoline pumps had a very wide range of designs to solve the mechanical problems of pumping, reliable measurement, safety, and aesthetics. This has led to some popularity in collecting antique dispensers, especially in the US.<ref>{{cite news| url=https://www.nytimes.com/2008/10/05/automobiles/collectibles/05PETRO.html?fta=y | work=The New York Times | title=Filling Up the Backyard With a Gas Station | first=Dave | last=Caldwell | date=October 5, 2008 | access-date=May 3, 2010}}</ref> === Fuel nozzles === Nozzles are attached to the pump with flexible hoses, so they can reach the vehicle's filler inlet. The hoses are robust to survive heavy wear and tear, including exposure to weather and being driven over, and are often attached using heavy spring or coil arrangements to provide additional strength. A breakaway valve is also fitted to the hose so that the nozzle and hose will detach and fuel flow stop if a motorist drives off with the nozzle still in the filler. Nozzles are usually color-coded to indicate which grade of fuel they dispense, but the color-coding differs between countries and even retailers. For example, a black hose and handle in the UK indicate that the fuel dispensed is diesel, and a green dispenser indicates unleaded fuel; the reverse is common in the US. ====Misfueling==== Some nozzles are designed to prevent the motorist selecting the wrong fuel. The nozzle on diesel pumps is supposed to be larger so that it cannot fit into the filler pipe on a vehicle tank designed for gasoline. However, the larger diameter diesel nozzles are not an actual requirement, and many diesel pumps have been fitted with standard gasoline nozzles. Also, the nozzle for leaded gasoline is wider than for unleaded, and the fill pipe on vehicles designed for unleaded-only was made narrower to prevent misfueling. Some diesel fuel tanks are designed to prevent the wrong type of nozzle from being used. === Blending === In some countries, pumps can mix two fuel products together before dispensing; this is referred to as blending or mixing. Typical usages are in a "mix" pump to add oil to petrol for [[two-stroke cycle|two-stroke]] [[motorcycle]]s, to produce an intermediate [[octane rating]] from separate high and low octane fuels, or to blend [[hydrogen]] and [[compressed natural gas]] ([[HCNG]]). Retailers benefit by offering three grades of fuel while only having to stock two. This frees up both working capital and tank capacity and improves fuel turnover. [[File:Gas pump display, Jacksonville, FL.jpg|thumbnail|right|A pump display in [[Jacksonville]], [[Florida]]]] === Flow measurement === The equipment must accurately measure the amount of fuel pumped. [[Flow measurement]] is almost always done by a 4 stroke piston meter connected to an electronic encoder.<ref name=ukcert/> In older gasoline pumps, the meter is physically coupled to reeled numerical displays (moving wheels or cylinders with numbers on the side), while newer pumps turn the meter's movement into electrical pulses using a [[rotary encoder]]. === Metrology === ==== Gasoline ==== {{anchor|The Metrology of Gasoline}} Gasoline is difficult to sell in a fair and consistent manner by volumetric units. It expands and contracts significantly as its temperature changes. Its [[coefficient of thermal expansion]] at 20&nbsp;°C is about 4.5 times that of water. In the US, the [[National Institute of Standards and Technology]] (NIST) specifies the accuracy of the measurements in Handbook 44,<ref name=hb44>{{cite journal |title=Handbook 44 |journal=Nist |date=20 November 2014 |publisher=National Institute of Standards and Technology |url=https://www.nist.gov/pml/wmd/pubs/hb44.cfm}}</ref> though states set their own legal standards. The standard accuracy is 0.3%, meaning that a {{convert|10|usgal|L|1|adj=on}} purchase may actually deliver between {{convert|9.97|and|10.03|usgal|L|1|abbr=on}}. The reference temperature for gasoline volume measurement is 60&nbsp;°F or 15&nbsp;°C.<ref name=sta/> Ten gallons of gasoline at that temperature expands to about {{convert|10.15|usgal|L|1|abbr=on}} at {{convert|85|°F|°C}} and contracts to about {{convert|9.83|usgal|L|1|abbr=on}} at {{convert|30|°F|°C}}. Each of the three volumes represents the same theoretical amount of energy. In one sense, a given volume of gasoline purchased at 30&nbsp;°F has about 3.2% more potential energy than the same volume purchased at 85&nbsp;°F. Most gasoline is stored in tanks underneath the [[filling station]]. Modern tanks are non-metallic and sealed to stop leaks. Some have double walls or other structures that provide a side benefit of thermal insulation while pursuing the main goal of keeping gasoline out of the soil around the tank. So while the air temperature can easily vary between {{convert|30|and|85|°F|}}, the gasoline warms or cools much more slowly, especially underground, as deep soil temperature tends to remain in a narrow range throughout the year, regardless of air temperature. Temperature compensation is common at the wholesale level in the United States and most other countries. At the retail level, Canada has converted to automatic temperature compensation, and the UK is converting, but the United States has not converted. Automatic temperature compensation, known as Standard Temperature Accounting in the UK, may add a tiny amount of additional uncertainty to the measurement of about 0.1%.<ref name=sta>{{cite web |title=STA Guidance |date=Feb 2016 |url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/504706/STA_Guidance_Feb_2016_version_11.pdf}}</ref> There are far fewer retail outlets for gasoline in the US today than there were in 1980. Larger outlets sell gasoline rapidly, as much as {{convert|30000|usgal|L|sigfig=2|abbr=on}} in a single day, even in remote places. Most finished product gasoline is delivered in 8,000- to 16,000-gallon [[tank trucks]], so two deliveries in a 24-hour period are common. Gasoline spends so little time in the retail sales system that its temperature at the point of sale does not vary significantly from winter to summer or by region. Canada has lower overall population densities and geographically larger gasoline distribution systems, compared with the United States. Temperature compensation at the retail level improves the fairness under those conditions. In the United States, each state has its own Department of Weights and Measure, with the authority to perform all testing and certification, issuing fines for non-compliance. For example, in 2007 Arizona found that 9% of all pumps were off by at least 2.5% (the threshold for fines), evenly split between overcounting and undercounting fuel.<ref>{{Cite web|url=https://www.azcentral.com/news/articles/2008/07/01/20080701biz-gaspumps0630.html?nclick_check=1|title = Help Center - the Arizona Republic}}</ref> [[File:Florida Department of Agriculture Petroleum Inspection (cropped).jpg|thumb|A state petroleum inspector visiting a [[Mobil]] station in [[Port Charlotte, Florida]]]] In many jurisdictions, regular required inspections are conducted to ensure the accuracy of gasoline pumps. For example, the [[Florida Department of Agriculture and Consumer Services]] conducts regular tests of calibration and fuel quality at individual dispensers. The department also conducts random undercover inspections using specially designed vehicles that can check the accuracy of the dispensers. The department issues correction required notices to stations with pumps found to be inaccurate.<ref>{{cite web|url=http://www.doacs.state.fl.us/standard/petro/index.html|title=Bureau of Petroleum Inspection|access-date=2011-12-10|publisher=Florida Department of Agriculture and Consumer Services|archive-url=https://web.archive.org/web/20101202102912/http://www.doacs.state.fl.us/standard/petro/index.html|archive-date=2010-12-02|url-status=dead}}</ref> Most other US states conduct similar inspections. In Canada, inspections are regularly conducted by the federal government agency [[Measurement Canada]]. Inspection dates and test results are required, by law, to be displayed to consumers on a sticker on gasoline pumps. Under the 2011 Fairness at the Pumps Act, a vendor with a modified or poorly maintained dispenser can be fined up to $50,000. However, virtually all pumps that fail inspection in Canada do so for general calibration errors caused by use over time. Intentional modification for the purpose of deceiving consumers is extremely rare, as are prosecutions.<ref>{{Cite web|url=https://ottawacitizen.com/news/politics/four-years-later-not-a-single-penny-of-fines-under-gas-pumps-law|title=Four years later, not a penny of fines under gas-pumps law|last1=McGregor|first1=Glen|website=Ottawa Citizen |date=2015-05-14|language=en|access-date=2019-02-27}}</ref> ==== Hydrogen ==== {{anchor|The Metrology of Hydrogen}} [[Hydrogen fuel]] dispensers<ref>[http://www.sae.org/servlets/pressRoom?OBJECT_TYPE=PressReleases&PAGE=showRelease&RELEASE_ID=2620 SAE International publishes new standard, SAE J2601, to establish worldwide basis for H2 fueling of fuel cell electric vehicles]</ref> in use on [[hydrogen stations]] dispense by the kilogram.<ref>[https://www.nbcnews.com/id/25413866 LA gas station gets hydrogen fuel pump]</ref> In the US, the [[National Institute of Standards and Technology]] (NIST) specifies in Handbook 44 that the tolerance of the measurements is to be 2.0%.<ref>[https://www.nist.gov/pml/div685/hydrogen-meter-072114.cfm Fill er up- NIST develops prototype meter test for hydrogen refueling stations]</ref> Worldwide regulations are discussed under [[International Organization of Legal Metrology|OIML]] R 139 ([[compressed hydrogen]]).<ref>[https://www.nist.gov/pml/wmd/pubs/upload/06-bod-appb-amc-09-pub15-final.pdf Report on the activities of the OIML and regional legal metrology organizations]</ref> Hydrogen pumps may be regulated under terms drawn from an industry technical standard, [[Society of Automotive Engineers|SAE]] J2601.<ref>[http://www.sae.org/servlets/pressRoom?OBJECT_TYPE=PressReleases&PAGE=showRelease&RELEASE_ID=2620 SAE International Publishes New standard, SAE J2601, to Establish Worldwide Basis for H2 Fueling of Fuel Cell Electric Vehicles]</ref> ===Communications components=== Technology for communicating with gasoline pumps from a [[point of sale]] or other controller varies widely, involving a variety of hardware ([[RS-485]], [[RS-422]], [[current loop]], and others) and proprietary software protocols. In the past, this gave pump manufacturers [[vendor lock-in]] for their own point-of-sale systems, since only they understood the protocols.<ref>[http://www.ifsf.org/Software/IFSF%20Management%20Intro%20-%20V3.01.pdf IFSF Management Intro, sec 1.1 Background history] {{webarchive |url=https://web.archive.org/web/20050824121152/http://www.ifsf.org/Software/IFSF%20Management%20Intro%20-%20V3.01.pdf |date=August 24, 2005 }}</ref> An effort to standardize in the 1990s resulted in the [[International Forecourt Standards Forum]], which has had considerable success in Europe, but less elsewhere. By October 2017, all US gasoline pumps with credit card readers had to support [[EMV]] payment. A year before this rule came into force, a third of 750,000 pumps needed upgrading at a cost of $6,000 to $17,000 each<ref>{{cite web|url=https://www.kompareit.com/business/retail-convert-gas-pump-terminals-to-emv.html|website=kompareit.com|access-date=September 23, 2020|last=Smith|first=Ashley|title=How Much Does It Cost to Convert My Gas Pump Terminals to Be EMV Chip Ready?}}</ref> plus the cost of new EPOS hardware and software. With some software not expected to be ready, some [[Fuel card|fleet cards]] not having [[Smart card|chip technology]] available in time, not enough technicians for the installations, and many businesses unable to afford the upgrade, it was predicted the conversion would take until 2021.<ref>{{cite news|url=https://www.chicagotribune.com/business/ct-gas-station-chip-card-upgrade-20161031-story.html|title=For gas-station operators, chip card upgrade is a pain in the pump|last=Kharif|first=Olga|work=[[Chicago Tribune]]|via=[[Bloomberg Businessweek]]|date=October 31, 2016|access-date=November 13, 2019}}</ref> === Automatic cut-off === {{anchor|Automatic cut-off in gasoline pumps}} The shut-off valve was invented in [[Olean, New York]], in 1939 by Richard C. Corson. At a loading dock at the [[Socony-Vacuum Oil Company]], Corson observed a worker filling a barrel with gasoline and thought it inefficient. The sound of a toilet flushing later gave him the idea for a "butterfly float." After developing a prototype with his assistant, Paul Wenke, Corson gave the suggestion to the company who later filed for a patent in his name. The initial intent of the device was to "allow a person to fill more than one barrel [of gasoline] at the same time."<ref>{{cite web|url=https://www.google.com/patents?id=N5VFAAAAEBAJ&printsec=abstract&source=gbs_overview_r&cad=0#v=onepage&q&f=false |title=Patent US2316934 - Barrel Filler|access-date=2011-12-10}}</ref> This mechanism eventually developed into the modern gasoline pump cut-off valve.<ref>{{cite news| last=Sampson|first=Julia |title=Did you know? Gas Pump shut-off valve was invented in Olean |newspaper=Olean Times Herald |date=April 26, 2010 }}</ref> Most modern pumps have an automatic cut-off feature that stops the flow when the tank is full. This is done with an auxiliary sensing tube running from just inside the mouth of the nozzle to a [[Venturi pump]] in the pump handle. A mechanical valve in the pump handle detects a change of pressure and closes, preventing the flow of fuel.<ref>{{cite web |url=http://www.pa.msu.edu/sciencet/ask_st/122591.html |title=12/25/1991 How does a gas pump shut off automatically when the gas tank is full? |publisher=Pa.msu.edu |access-date=2011-12-10 |archive-url=https://web.archive.org/web/20111028121633/http://www.pa.msu.edu/sciencet/ask_st/122591.html |archive-date=2011-10-28 |url-status=dead }}</ref><ref>{{cite web |last=Plueddeman |first=Charles |url=http://editorial.autos.msn.com/article.aspx?cp-documentid=1116074&topart=hybrids |title=Unraveling Automotive Mysteries |publisher=Editorial.autos.msn.com |access-date=2011-12-10 |archive-url=https://web.archive.org/web/20120531122031/http://editorial.autos.msn.com/article.aspx?cp-documentid=1116074 |archive-date=2012-05-31 |url-status=dead }}</ref> === Other components === A modern fuel pump will often contain control equipment for the [[vapor recovery]] system, which prevents gasoline vapor from escaping to the air. In the UK, for example, any new forecourt with a predicted throughput in excess of 500 m³ per month is required to have active vapor recovery installed. ===Early designs=== <gallery> <!-- alphabetized by country and state where the image was taken --> File:Petrol bowser Gundagai.jpg|Restored petrol bowser, [[Gundagai]], Australia File:Zapfsäule BP Wien.jpg|Fuel pump in [[Vienna]], Austria. File:Ömossa 31.jpg|A 1991 photograph of a fuel pump in [[Ömossa]] village, [[Kristinestad]], [[Finland]]. File:Petrol Pump, Quillan, France.jpg|Antique fuel pump in [[Quillan]], [[France]]. File:Historische Zapfsaeule.jpg|Antique [[diesel fuel]] pump located at [[Roscheider Hof Open Air Museum]], [[Konz]], Germany. File:Verschiedene Zapfsäulen Deutsches Museum.jpg|Display of various antique fuel pumps at [[Deutsches Museum]] in [[Munich]], Germany. File:Alte Zapfsäulen 1X7A7980.jpg|Display of various antique fuel pumps at Retro Classics 2018 in [[Stuttgart]], Germany. File:Old-Gas-Pumps.jpg|Old [[Soviet Union]] fuel pumps. File:G-Morcomb's Service Station Gas Pumps.jpg|Gasoline pumps once used at the historic Morcomb's Service Station in [[Glendale, Arizona]]. Included is a 1918 Visi Bowl pump (left) File:MobilgasPumpsAntique09162007.JPG|Antique "[[Mobil]]gas" pumps, manufactured by [[Tokheim]], located in [[Wilton, Connecticut]]. File:Savannah Georgia gas_pump.jpg|Antique gasoline pump from [[Savannah, Georgia]]. File:SoulsbyServiceStation MtOliveIL.jpg|Two types of [[Royal Dutch Shell|Shell]] gasoline pumps at Soulsby Service Station in [[Mount Olive, Illinois]]. File:Old_Gas_Pumps_at_2012_GMAS.jpg|Four old-fashioned gasoline pumps at the 2012 Greater Milwaukee Auto Show. </gallery> == Regulation == {{anchor|Regulations}} Since gasoline pumps are the focal point of distributing fuel to the general public, and fuel is a hazardous substance, they are subject to stringent requirements regarding safety, accuracy and security. The exact details differ between jurisdictions and can depend to some extent on politics. For example, in countries fighting corruption, such as Mexico,<ref>{{cite news|url=https://articles.latimes.com/2006/jun/13/business/fi-stickup13 |first1=Marla |last1=Dickerson |first2=Carlos |last2=Martinez |title=Not Quite Measuring Up at Mexico's Gas Pumps |newspaper=Los Angeles Times |date=2006-06-13 |access-date=2011-12-10}}</ref> gasoline pumps may be more stringently monitored by government officials, to detect attempts to defraud customers. Typically, individual pumps must be certified for operation after installation by a [[weights and measures]] inspector, who tests that the pump displays the same amount that it dispenses. In Taiwan, continuous fuel flow is not allowed for self service pumps; the driver must grip the nozzle until the desired amount of fuel has been delivered or until the shutoff switch is triggered. This is also the case in Australia and the UK. <ref>{{cite web |title=QLD: Safety alert issued over fuel dispensing nozzle latches |url=https://www.aihs.org.au/news-and-publications/news/qld-safety-alert-issued-over-fuel-dispensing-nozzle-latches |website=AIHS |access-date=20 February 2022 |date=22 November 2016}}</ref> {{Citation needed|reason=Need similar citation for Taiwan, UK|date=February 2022}} == See also == [[File:Fuel tank pictogram on 50 ccm scooter.jpeg|thumb|right|upright|The [[pictogram]] of a gasoline pump is used internationally as a symbol on fuel gauges of vehicles, here on a 50 ccm Chinese-made [[Scooter (motorcycle)|scooter]] from 2008]] * [[Fast fuel system]] * [[Electric car charger]] * [[Cascade storage system]] * [[HCNG dispenser]] * [[Fisogni Museum]] == References == {{Reflist|colwidth=30em}} == External links == {{Commons category|Petrol pumps}} * [http://www.straightdope.com/classics/a1_263.html How does a gas pump know to shut itself off?] from ''The Straight Dope'' {{Authority control}} [[Category:Pumps]] [[Category:Petroleum infrastructure]] [[Category:American inventions]] [[Category:Filling stations]] [[Category:19th-century inventions]]'