3. Impeller is keyed onto the shaft.
4. There are collars on the side of the impeller.
5. The shaft passes throug h the pump casing.
6. It is a good sign when drops of liquid seep through the packing.
7. The electric motor is connected t o the pump by the coupling.
8. The shaft is protected from handled liquid.
V. Перевести :
1. The capacity of a centrifugal pump is 150 m3/hour.
2. Pumps are designed for sea and fresh water supply.
3. The pump casing is closed by a cover on the bottom.
4. Halves of a split pump are secured by means of bolts.
5. Drops of liquid can seep through the packing.
6. The clearance between the seals and a collar is very small.
7. Impeller is placed onto the shaft and is keyed.
8. The capacity of this pump is 14 HP at shaft rotation equal to 1400 revolutions per minute.
VI. Дайте краткие ответы по тексту. Дайте их в форме диалога.
1. What is the most often used type of pumps in ships ? it is a centrifugal pump.
2. Where are these pumps to be found ? They are found in engine rooms.
3. What is the function of the pumps ? They handle either salt water or fresh water.
* * *
1. What does the pump consist of ? It consists of a one – impeller centrifugal pump and of an electric motor .
2. By means of what are the two halves connected ? They are connected by means of studs.
3. What is the stationary part fitted with ?it is fitted with the suction and discharge nozzles.
* * *
1. Where is a stuffing box with packings formed ? it is formed where the shaft passes through the pump casing .
2. How should these packings be pressed ? they should not be pressed too tight.
3. Is it good when liquid seeps through the packings ? it is not good, only a few drops are allowed to seep.
- 5 –
* * *
1. Is impeller keyed onto the shaft ? Yes, it is.
2. By means of what is it fixed ? It is fixed by means of shaft key.
3. How is the shaft protected against liquid ? It is protected withtwo top and one bottom bushings.
* * *
1. Collars are on the sides of the impeller , aren't they ? Yes, they are.
2. What is the clearance between these collars and seal rings ? the clearance is very slight.
* * *
1. What lubricates packings ? The liquid handled lubricates packings.
2. From where does this liquid flow ? this liquid flow from the discharge chamber.
VII. Рассказать о вертикальном центробежном насосе. Использовать план.
1. Функции насосов на судне. 2. Конструкция : корпус насоса ,вал. 3. Смазка. 4. Рабочие характеристики.
ИНСТРУКЦИИ ПО ЭКСПЛУАТАЦИИ И ТЕХОБСЛУЖИВАНИЮ.
Пуск.
1. Открыть контрольный всасывающий клапан насоса , открыть одновременно воздушный клапан на верхней стороне для того, чтобы облегчить полное наполнение корпуса насоса.