Operation and maintenance instructions

Starting (the centrifugal pump and axial-plunger pump)

1) Open the suction check valve wide, opening at the same time the air vent on the top side.

2) Close the air vent as soon as liquid flows out of it.

3) Start the motor leaving the discharge valve closed.

4) Check that direction of rotation is as indicated by the arrow.

5) Slowly open the discharge check valve until operating requirements are reached.

6) Check on the ammeter that power requirements do not exceed the motor possible rating.

7) Check tightness of the packing gland. Leaks must be reduced to a few drops it is required to prevent harmful heating of the packing and the shaft.

During operation

The pump output is to be controlled by operating on the discharge valve and never on the suction valve which must always remain wide open.

Stopping

After switching off the motor close the suction and the discharge valves of the pump.

Part B. Translate the following sentences into Russian.

1. Check the wear of internal pans by throttling the suction valve at the pump and noting the amount of vacuum pulled by the pump. 2. If neither steam nor power is available, move the pump by hand. 3. It may be necessary to renew the gears, the casing or the gaskets which are sometimes fitted between the casing flanges. 4. Have you checked all clearances? If you’ve done it, renew worn parts if necessary. 5. It looks like complete failure of the starboard circulating pump, the jacket water temperature is very high.

Exercise 6. Discuss the causes and remedies of the most common troubles with the pumps

loss	потеря
trouble, obstruction	помеха, препятствие
to deliver	подавать, доставлять
insufficient	недостаточный
to result from	возникать в результате
partially	частично
passage	проход
to rupture	прорывать, разрывать
to eliminate	устранять
capacity	производительность
leakage	течь
stuffing box	корпус сальника

Irregularities, their causes and remedies

Symptom:	Cause:	Remedy:
	Reciprocating pumps
Loss of suction	1) Obstructions in the suction line.	Check suction valves.
	2) Air in the system.	Open the air cocks vents on the liquid end valve chest, leave them open until water flows out.
	Centrifugal pumps
A pump doesn't deliver any liquid	1) Air in the pump case.	Let the air flow out.
	2) Insufficient speed of the pump.	Check the electromotor, bearings and gland box.
	3) Excessive large pressure resulting from a partially clogged valve or some obstruction in the discharge line.	Check the valve and adjust it.
	4) Clogged impeller passages.	Stop the pump and clean the impeller.
	5) Ruptured suction line.	Stop the pump, eliminate leakages in the suction line.
A pump operates at insufficient capacity	1) Air leakage into the suction line or stuffing boxes.	Eliminate leakages.
	2) Mechanical defects such as worn wearing rings, impellers, stuffing box packing or sleeves.	Stop the pump, find the trouble and correct it.

Exercise 7. Translate into English.

1. Производительность центробежного насоса равна 150 м3/ч. 2. Насосы спроектированы для подачи пресной и морской воды. 3. Корпус насоса снизу закрывается крышкой. 4. половинки разъемного насоса крепятся болтами. 5. Капли жидкости могут просачиваться через уплотнение. 6. Зазор между уплотнениями и буртиком очень мал. 7. Крылатка насаживается на вал и фиксируется шпонкой.