Text Types of Hydraulic Fluids

· Can you explain what a hydraulic fluid is? What is its main purpose?

· Read the definition and the brief explanation of «hydraulic fluid» and compare this information with your personal knowledge.

Hydraulic fluids are a large group of fluids used as the motive medium in hydraulic machinery. Fluid types include synthetic compounds, mineral oil, water, and water-based mixtures. The fluids are found in machinery and equipment ranging from brakes, power steering systems, and transmissions to backhoes, excavators, garbage trucks and industrial shredders. Hydraulic systems are very common in aircraft flight control systems. They will work most efficiently if the hydraulic fluid used has low compressibility.

(from http://en.wikipedia.org/wiki/Hydraulic_fluid)

 

 

motive medium движущий, приводящий в движение

steering system система рулевого управления

backhoe канавокопатель с обратной лопатой

shredder комбинированная установка для дробления

marine морской

to dredge копать с помощью землечерпалки

compressibility сжимаемость, прессуемость

· Translate the following names of the hydraulic fluid components from English into Russian and pay special attention to the pronunciation while reading aloud:

 

castor oil, glycol, esters, ethers, mineral oil, organophosphate ester, polyalphaolefin, propylene glycol, or silicone. oils, butanol, esters, phthalates, adipates, bis(2-ethylhexyl) adipate), polyalkylene glycols (PAG), phosphate esters, tributylphosphate, silicones, alkylated aromatic hydrocarbons, polyalphaolefins, polyisobutenes.

Words and phrases:

shipboard systems системы на борту корабля

additive присадка; добавка

foam пена

viscosity вязкость, коэффициент вязкости

electrohydraulic steering электрогидравлический рулевой привод

deckmachinery systems системы палубных механизмов

shock absorber амортизатор

seal materials герметизирующий материал

compatible with быть совмещаемым, подходить

desired желаемый

flammable огнеопасный; легковоспламеняющийся

to be subjected to подлежать

contamination загрязнение; механические примеси

malfunction нарушение нормальной работы, сбой

valve seating притирка клапана, седло клапана

stringent строгий; обязательный, точный

to enhance увеличивать, усиливать, улучшать

load-carrying capacity грузоподъёмность; подъёмная сила;

smothering гашение, тушение, удушье

catapult retracting engines катапультное устройство

jet blast deflectors отражатель реактивной струи

handling systems системы для работы, транспортировки

 

 

There have been many liquids tested for use in hydraulic systems.

Currently, liquids being used include mineral oil, water, phosphate ester, water-based ethylene glycol compounds, and silicone fluids. The three most common types of hydraulic liquids are petroleum-based, synthetic fire-resistant, and water-based fire-resistant.

The most common hydraulic fluids used in shipboard systems are the petroleum-based oils.

These fluids contain additives to protect the fluid from oxidation (antioxidant), to protect system metals from corrosion (anticorrosion), to reduce tendency of the fluid to foam (foam suppressant), and to improve viscosity.

Petroleum-based fluids are used in surface ships’ electrohydraulic steering and deckmachinery systems, submarines’ hydraulic systems, and aircraft automatic pilots, shock absorbers, brakes, control mechanisms, and other hydraulic systems using seal materials compatible with petroleum-based fluids.

Petroleum-based oils contain most of the desired properties of a hydraulic liquid. However, they are flammable under normal conditions and can become explosive when subjected to high pressures and a source of flame or high temperatures. Nonflammable synthetic liquids have been developed for use in hydraulic systems where fire hazards exist.

Cleanliness in hydraulic systems has received considerable attention recently. Some hydraulic systems, such as aerospace hydraulic systems, are extremely sensitive to contamination. Fluid cleanliness is of primary importance because contaminants can cause component malfunction, prevent proper valve seating, cause wear in components, and may increase the response time of servo valves.

The inside of a hydraulic system can only be kept as clean as the fluid added to it. Initial fluid cleanliness can be achieved by observing stringent cleanliness requirements or by filtering all fluid added to the system.

The most widely used water-based hydraulic fluids may be classified as water-glycol mixtures and water-synthetic base mixtures. The water- glycol mixture contains additives to protect it from oxidation, corrosion, and biological growth and to enhance its load-carrying capacity.

Fire resistance of the water mixture fluids depends on the vaporization and smothering effect of steam generated from the water. The water in water-based fluids is constantly being driven off while the system is operating. Therefore, frequent checks to maintain the correct ratio of water are important. The water-based fluid used in catapult retracting engines, jet blast deflectors, and weapons elevators and handling systems. (from http://www.tpub.com/content/engine/14105/css/14105_39.htm)

 

· Look through the text again and decide if the following statements true or false:

1. There are a lot of types of hydraulic liquids and some of them include mineral oils.

2. The most wide-spread hydraulic fluids are synthetic fire-resistant fluids.

3. The main function of hydraulic fluids is to protect system metals from corrosion.

4. Petroleum-based fluids are used in catapult retracting engines, jet blast deflectors.

5. The hydraulic systems are not sensitive to contamination.

6. Cleanliness in hydraulic systems is very important.

 

 

· Match the following words with their definitions:

 

fluid a. the exertion of continuous force on a body by another

mixture b. petroleum

pressure c. a substance, liquid, lacking definite shape

oil d. ingredients mixed together to produce a substance

freezing point e. reduced to a simpler molecular structure

compound f. operated by liquid

hydraulic g. a mixture of two or more things

degradable h. a level of temperature at which a change of state occurs

 

 

· Change the following sentences into the Active or the Passive:

1. Petroleum-based fluids are used in surface ships’ electrohydraulic steering and deckmachinery systems.

2. Liquids being used include mineral oil, water, phosphate ester, water-based ethylene glycol compounds, and silicone fluids.

3. Nonflammable synthetic liquids have been developed for use in hydraulic systems where fire hazards exist.

4. Cleanliness in hydraulic systems has received considerable attention recently.

5. The most widely used water-based hydraulic fluids may be classified as water-glycol mixtures and water-synthetic base mixtures.

6. The water in water-based fluids is constantly being driven off while the system is operating.

 

 

· Give English definitions to the following words in Russian:

Гидравлическая жидкость, гидросистема, вязкость, испарение, антикоррозионный, минеральное масло, антиокислительный, клапан, присадка, высокая температура, вспышка, амортизатор, противообледенительный агент, рабочее тело, гидропривод, гликоль, эфир, амортизационная жидкость, тормозной, давление, антипенный, органическое соединение.

 

· Translate from Russian into English:

Гидравлические жидкости — жидкости, применяемые в машинах и механизмах для передачи усилий, которые передаются через жидкую среду для приведения в действие исполнительных механизмов. Гидравлические жидкости используют в гидропередачах самолетов, экскаваторов, кранов, бульдозеров и других машин, в тормозных системах автомобилей, в гидравлических системах промышленного оборудования и т.д.

Гидравлические жидкости должны обладать определенным комплексом физико-химических и эксплуатационных свойств. Они должны быть устойчивыми при хранении и эксплуатации, не образовывать осадков; обладать малой вспениваемостью, хорошими смазочными и противоизносными свойствами; не содержать механических загрязнений, особенно абразивных частиц, их вязкость не должна резко изменяться с температурой. Кроме того, гидравлические жидкости не должны вызывать коррозию металлов и разрушать другие конструкционные материалы. В ряде случаев необходимы негорючие жидкости.

Во все специальные жидкости вводят, как правило, антикоррозионные присадки, в гидравлические – тормозные и амортизаторные, кроме того – вязкостные, противоизносные и антиокислительные, а в охлаждающие – антипенные присадки. Антиобледенительные жидкости получают обычно смешением этилового спирта с водой.

Нефтехимическая промышленность выпускает более 20 сортов минеральных масел, используемых в гидравлических системах.

(With the help of http://www.xumuk.ru/encyklopedia/1009.html)

 

· Split into 2-3 groups. The task of each group is to invent a new hydraulic fluid. It’s up to you to decide what kind of vehicle it will refer to. Describe the components of your fluid and tell what functions each component will be responsible for. Give it the name and describe the performance of your fluid.

 

 

Use the following words and phrases:

to be broadly used as

to be for use in

to be designed for

to employ sth

to possess

suitable

conventional

in comparison to

to be applied in

content

to contain

 

 

· Read the ad. Its tone is rather reserved. You have just developed an innovative hydraulic fluid which needs to be promoted on the market.

 

Chevron Aviation Hydraulic Fluids are both manufactured from specially selected, highly refined, low viscosity and low pour point petroleum base stocks. They both contain a superior, shear resistant viscosity index improver, which provides an extremely high viscosity index. They also contain an antiwear agent and an oxidation inhibitor. Both contain a red colored dye to hasten identification.

The low viscosity of the base stock used for these fluids and the shear stable viscosity index improver provide the extremely high viscosity index (300+) which is critical for a lubricant or hydraulic fluid operating over the very broad temperature range of -54°C to 135°C.

Since this is a conventional petroleum base stock, and not a synthetic, the low pour point is critical to minimize filter plugging.

In addition, the antiwear additive and foam inhibitor help prevent pump cavitation and can extend both pump and servo valve life.

(From http://www.matweb.com/search/datasheettext)

 

 

Unit 3