### Classification of Reciprocating Pump

Follow are the three fields in which the reciprocating are classified

1. According to the contact between water and plunger
2. According to the number of cylinders
3. According to the air vessel

### According to the contact between water and plunger

#### Single acting pump

A single acting pump is one which has one suction valve, delivery valve and one suction and delivery pipe. It suck up the fluid only in one direction and in single stroke called  suction stroke and deliver it in a single stroke called delivery stroke

#### Double acting pump

A double acting pump is one which has two suction valves, delivery valves and two suction and delivery pipes. If we suppose that piston is in the center of the cylinder then one suction and delivery pipe is on one side and one delivery and suction pipe is on other side of the piston.

### According to the number of cylinders

#### 1. Single cylinder pump

Single cylinder pump is one in which their is only cylinder connected to a single shaft. It could be a single acting or double acting pump.

#### 2. Double cylinder pump

Double cylinder pump is one which have two cylinder attached to a single shaft.Separate suction and delivery valve is provided to each cylinder.Crank of the pump is set at an angle of 180

#### 3. Triple cylinder pump

When the pump has three cylinders attached to a single shaft then the pump is called triple cylinder pump. Crank is set at an angle of 120

### According to the air vessel

#### 1. With air vessel

Some reciprocating pump are provided with a separate air vessel attache to the suction and delivery valve. Its main function is to accumulate excess quantity of water by compressing the air in the vessel

#### 2. With out Air vessel

Some pump lack the air vessel because of the nature of their work. for example the reciprocating boiler feed pumps does not have air vessel because they may introduce air into the deaerated water