| 1) as much as, as many as 2) auxiliary 3) by virtue of smth 4) calculation 5) consume 6) cooling water towers 7) cross-section 8) design 9) duplex 10) electric current 11) frictional resistance 12) ignition 13) income | 1) 2) 3) - 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) | 14)interposed 15)impetus 16)one may 17)one must 18)the only 19)pressure loss 20)plunger 21)range 22)repair 23)result from 24)result in 25)shaft 26)triplex 27)velocity | 14) 15) 16) 17) 18) 19) 20) 21) 22) 23) - 24) - 25)1), ; 2) 26) 27), |
II. Translate the following words and phrases into Russian.
| 1. frictional resistance 2. cross-section 3. magnitude 4. inner surface | 5. initial pressure 6. equal intervals 7. valuable 8. engine | 9. viscosity 10. obtainable fuel 11. capacity 12. to overcome |
III. Find the proper English equivalents in the text.
| 1. 2. - 3. 4. 5. - 6. - 7. 8. | 9. 10. () 11. 12. 13. () 14. 15. |
IV. Read and translate the text.
PUMPING STATIONS
From the oil field storage reservoir the main trunk line starts and here the first main line pumping station is located. When oil is pumped through a pipe, the transmission is opposed by frictional resistance to flow which is a product of two factors. The first of these is the frictional resistance developed between the inner wall of the pipe and the outer cylinder of oil making contact with it. The second is due to the internal resistance to movement of the oil itself, the fluid friction resulting from many oil surfaces sliding over each other throughout the entire cross-section of the pipe. The magnitude of the resistance offered by these frictional forces will depend upon the length of the pipe through which the oil is pumped, the velocity of flow, the conditions of the pipe's inner surface and viscosity of the oil. The latter property will vary within wide limits with changes in temperature of the oil. Variation in oil temperature from summer to winter will cause sufficient change in oil viscosity to affect the capacity of a line at constant pressure as much as ten per cent on average crude oil and even more on the heavier grades.
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In former years attempts were made to heat oil before its leaving a pumping station in order to reduce its viscosity which resulted in increasing line capacity, heat from the exhaust of steam pumps being utilized. However, the oil soon lost its temperature and the gain in capacity was slight. Modern practice on average crude oil does not provide for preheating. Only in the case of heaviest oils transported for a short distance is preheating justified at present.
The motivating agent enabling oil to overcome these several resistances to flow is the pump, which imparts a certain initial pressure to the oil, by virtue of which it moves through the pipe overcoming the resistance interposed until the pump pressure is entirely consumed. If flow is to continue the oi1 must then be given a new impetus by passing it through a second pump. The pressure loss per unit length of pipe is seen to be a quantity of prime importance in all pipe line calculations. Knowing this for a given set of conditions it will be possible to calculate the distance through which oil may be transmitted with a given initial pressure and the space between the pumping stations along the route of the line.
Pumping stations are usually located at approximately equal intervals and the equipment for all stations on the same line may be practically standardized.
The design of the station will depend to a large extent upon the type of power adopted. As oil is the most easily obtainable fuel, it is generally used as a source of power pumping stations along a line. In the case where oil is too valuable to be used as a fuel steam power is used. The main pumping station equipment usually consists of engines (either oil or steam ones) and pumps which are sometimes driven by the engines by shafts. There are different kinds of pumps. They may be either of vertical triplex or horizontal duplex plunger type operating at different pressures having capacity ranging from 5,000 to 45,000 bbls per day.
Auxiliary equipment includes cooling water towers for cooling the engines; generators for supplying electric current for engines ignition, the operation of water pumps and the illumination of the grounds and structures; and some storage tanks or reservoirs for storing the income oil in case of the pumps repair when they are stopped for some time.
