Decide whether the following statements are true or false according to the text.

1) Pressure conduits are more expensive than canals or flumes.

2) Pressure conduits may be used to avoid loss of water by seepage and evaporation.

3) Pipes must withstand stresses created by internal and external pressures, external loads and temperature changes.

4) Water-hammer pressures can’t be reduced by use of slow-closing valves, automatic relief valves, air chambers and surge tanks.

5) The principal pipe materials are copper, wrought iron, plastics, asphaltic fiber and brick.

6) Check valves permit flow in any direction.

7) Drain or blow off valves are necessary at the low points of a pipeline to prevent entry of pollution into the pure water.

8) Pressure-relief valves open manually at a predetermined pressure.

9) Surge tanks are installed on medium pipelines and they are usually open at the top and of sufficient height.

10) The bottom of the surge tank must be near reservoir level.

11) Surge tanks are often built wholly or partially underground.

12) Siphon action doesn’t exist in pressure pipe.

13) To prevent deposition of suspended solids at the bottom of the sag, the velocity in the sag pipe should be great enough.

Put the following sentences in the right order according to the text.

§  Water-hammer pressures can be greatly reduced by use of slow-closing valves, automatic relief valves, air chambers and surge tanks.

§  Flow in a sag pipe is under pressure and follows the principles of flow in pressure conduits.

§  Surge tanks are installed on large pipelines to relieve excess pressure caused by water hammer.

§  A pressure conduit is a conduit which is flowing full.

§  Gate valves, check valves, drain or blow off valves, pressure-relief valves are required for the proper functioning of a pipeline.

§  The internal pressure within a conduit is caused by static pressure and water hammer.

§  Pressure conduits are preferable for public water supplies because of the reduced opportunity for pollution.

§  Surge tanks are often built partially or wholly underground.

Answer the following questions.

1) What is a pressure conduit?

2) Why are pressure conduits preferable for public water supplies?

3) What stresses must pipes withstand?

4) What is caused by static pressure and water hammer?

5) What is known as water hammer?

6) How can water-hammer pressures be reduced?

7) What are the principal pipe materials?

8) What valves are required for the proper functioning of a pipeline?

9) Gate valves are used to regulate the flow in the pipe, aren’t they?

10) Do check valves permit flow in one direction only?

11) Where are check valves required at? Why?

12) Where are drain or blow off valves necessary at?

13) What is their function?

14) Why must the bottom of the surge tank be far enough below reservoir level?

15) Surge tanks aren’t often built partially or wholly underground, are they?

16) What are exposed surge tanks usually built of?

17) Must a surge tank be protected from freezing?

18) When should the minimum velocity in the sag pipe be great enough to prevent deposition of suspended solids at the bottom of the sag?

Make a plan of the text “Pressure Conduits” and write down its summary.

Match the words with their synonyms.

Find the opposites of the following words in the text.

Match the words in part A with part B. What materials are considered to be the principle pipe materials?

A. битумный материал, золото, сталь, бетон, серебро, асбестоцемент, ковкий чугун, известняк, древесина, чугун, плотноспекшаяся глина, кирпич, железобетон, гравий, медь, пластмасса, песок, камень

B. silver, asphaltic fiber, steel, wrought iron, brick, asbestos-cement, limestone, cast iron, gravel, concrete, vitrified clay, reinforced concrete, gold, rock, plastics, copper, wood, sand

Translate the words in the brackets.

1) A (напорный трубопровод) is a conduit which is flowing full.

2) If water is (недостаточно), pressure conduits may be used (избежать) loss of water.

3) Pressure conduits are preferable for (коммунальное водоснабжение).

4) The (внутреннее давление) within a conduit is caused by (статическим давлением) and (гидравлическим ударом).

5) Pressures can be reduced by use of (воздушных камер) and (уравнительных резервуаров), etc.

6) A large number of different types of valves are required for the (соответствующего) functioning of a (трубопровода).

7) A simple (уравнительный резервуар) is a (вертикальный стояк) connected to a pipeline.

8) Surge chambers for (туннелей) may be excavated in the (горной породе) above the tunnel if (геологические условия) are favorable.

9) (Электрические нагревательные элементы) have been used successfully to protect a surge tank from (замерзания).

10) If the water (содержит) (взвешенные наносы), the minimum velocity in the (дюкере) should be great enough to prevent (оседание) of these solids at the bottom of the sag.

11) Check valves are required at (соединениях) between a polluted water system and a portable water system to prevent entry of pollution into the (чистую воду).

Read the following text and fill in the missed words.

Hydraulic machinery

The two types of 1)_________ machinery which are of interest to the 2) _________ are pumps and turbines. A 3)_________ converts mechanical energy into hydraulic energy while a 4)_________ serves the opposite 5)_________. There are many types of pumps and turbines. Each type has its own 6)_________.

There are 7)_________ of turbines. They are the 8)_________ and the 9)_________. In the impulse turbine a free jet of water impinges on the revolving element of the machine which is exposed to 10)_________ pressure. In a reaction turbine flow takes place under pressure in a 11)_________ chamber.

There are many different types of pumps, but the two types which the hydraulic engineer will encounter most frequently are 12)_________ and 13)_________ pumps.