新闻中心

Industry News

所在位置:首页 >>News>>Industry News

Fuel Dispensing Equipment & Operation

作者:互联网    浏览:58659    发布时间:2015-9-11 9:10:43

Fuel dispensing equipment dispenses andmonitors liquid or gaseous fuel. Fuel dispensers are used to pump liquid fuelssuch as gasoline, diesel fuel, oil, or kerosene into a vehicle, aircraft,storage tank, or portable container. Gaseous fuel dispensers may refuelhydrogen- or syngas-powered vehicles or machinery, or simply be used to movegases from one location to another.

 

Liquid fuel dispensing equipment iswidely distributed in developed countries in the form of automotive gas pumps(petrol pumps in Commonwealth areas).

 

Fuel Type

Fuel dispenser design depends on theintended fuel type. A fuel type's volatility, flammability, boiling point, andother characteristics factor into a dispenser's design and construction.

 

Petroleum fuels include gasoline(petrol), diesel, and kerosene. Liquid petroleum fuels do not directly ignite.Instead, fumes from the fuel ignite when exposed to an ignition source andvaporize the remaining liquid, causing the liquid to burn as fumes itself.Gasoline and diesel are common automotive fuels, while kerosene is common asfuel for heaters, a component of many jet and rocket fuels, and an additive todiesel to prevent cold-temperature effects.

Compressed natural gas (CNG) andliquefied petroleum gas (LPG) are related compressible fuel types. CNG isprimarily comprised of methane, while LPG is a mixture of propane and butane.Both are relatively clean-burning but must be stored under pressure due totheir low boiling points. CNG and LPG are used for cooking, heating, andincreasingly as motorized vehicle fuel.

Alcohols include ethanol, butanol, andmethanol. They are employed as vehicle fuels or fuel additives in combinationwith gasoline.

Specialized or uncommon liquid fuelsinclude liquid hydrogen, ammonia, synthetic fuels, and biodiesel.

Some fuels, commonly termed fuel gases,are ordinarily gaseous. Fuel gases are used in gas burners, heaters, stoves,and occasionally to power vehicles. Before the widespread use of electricstreet lighting, gas-lit streetlamps burned fuel gas.

 

Natural fuel gas is produced during thepetroleum refining process and includes propane, butane, and regasified LPG.Natural gas, the uncompressed version of CNG, is naturally occurring in gasfield deposits.

Manufactured fuel gas is producedthrough artificial processes, most commonly by gasification. Manufactured gasesinclude coal gas, water gas, syngas, wood gas, and biogas. Manufactured gas wasused for lighting and cooking until the mid-20th century and is now found asgas turbine or combustion engine fuels.

Design and Operation

 

Typical fuel dispensers include severalsections, such as hydraulic, metering, and hose/nozzle portions. The hydraulicsection contains a rotary pump for drawing fuel from the storage tank and asolenoid/pilot valve to ensure that fuel flows only toward the dispenser andnot back into the pump. Commercial dispensers such as those found at gas/petrolstations may house multiple units connected to different storage tanks for thepurpose of supplying multiple fuels with different compositions or octaneratings.

 

An operational fuel dispenser containsa continuously running electric motor between the storage tank and thehydraulics portion of the unit for the purpose of maintaining a partial vacuumat the rotary pump inlet. When the nozzle opens, the storage tank draws suctionpressure from the inlet, causing fuel to flow toward the pumping unit. Anintermediary filter removes air bubbles or suspended solids from the fuel.

 

Fuel then flows through the pump andvalve and into the metering unit. This portion includes mechanical gearboxes,as in older pumps, or piston meters and encoders to measure and distribute aspecified amount of fuel or track fuel output. After the metering section, thefuel progresses through a flexible hose and into a nozzle that dispenses itinto a vehicle or storage tank.

 

Fuel dispensers range from largecommercial gas pumps to simple dispenser pumps for use with portable storagetanks.

 

Dispensing nozzles represent theinterface between the unit and the user. They are often equipped with safetyfeatures, some of which are listed below.

 

Nozzle size: Diesel dispensers use largernozzles that are incompatible with standard vehicle fillpipes to avoidmisfueling. However, this sizing is not a mandated requirement, and most dieselnozzles are color-coded.

Pressure-sensitive nozzles restrictflow until the fuel dispensing system is pressurized.

Breakaway valves allow the nozzle tobreak away from the hose and stop fuel flow if a vehicle begins moving with thenozzle still in the fillpipe.

Dual-plane nozzles include a swiveljoint to allow fueling from many different angles.

Quick-release nozzles have a single,coaxial coupling that eliminates the need for separate filling and ventingpoints

Products and Equipment

Manufacturers may supply completedispensing systems or the discrete components that comprise a system. Theseproducts include fuel meters, nozzles, hydraulics systems, and individualvalves or pumps.

 

Standards

Fuels and fuel gases are flammable, anddispensing them improperly or with faulty equipment can lead to fire orexplosions. For this reason fuel dispensing equipment often conforms tospecifications and recommendations contained in published standards like thoselisted below.

 

NFPA 30A—Code for motor fuel dispensingfacilities and repair garages

UL 87A—Investigation of power-operatedgasoline and ethanol dispensers

FAA AC 150/5230-4—Aircraft fuelstorage, handling, and dispensing at airports