Flashcards in Dynamic pumps Deck (80)

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1

## What is specific gravity?

### It is the ratio of the density compared to cool water. SG of water is 1. Less than 1 is lighter than water and more than 1 is heavier than water.

2

## What is the conversion of psi to kpa?

### 1 psi = 6.9 kpa

3

## What is the formula to determine pressure?

### Pressure=force / area

4

## What is atmospheric pressure?

### 14.7 psia

5

## How much pressure is lost with elevation gain?

### Approx 1/2 psi per 1000 feet gain

6

## What is head pressure?

### It is the height, in feet, of a column of water that is one foot square at the base

7

## What does water weigh?

### 62.4 lbs/cubic foot

8

## How much pressure is on One cubic foot of headwater?

### .433 psi

9

## What is differential pressure?

### It is the difference between the discharge pressure and the suction pressure

10

## What is vapour pressure?

### It is the pressure at which a liquid flashes into a vapour at a given temperature

11

## When the Pressure increases what happens to the boiling point?

### The boiling point also increases

12

## What are some causes of turbulent flow

### Bends, abrupt changes in cross-section, fittings in the pipe, velocity that is too high

13

## In Bernoulli's principle, what are the two types of energy that make up total head?

### Head pressure, velocity head

14

## What is the difference between static head, and dynamic(or total) head

### Static is the distance, and dynamic is the distance plus all the energy needed to move the fluid

15

## What is net positive suction head?

### It is a measure of head at the pump suction. It is commonly referred to as npsha or net positive suction head available

16

## How is net positive section head required determined?

### It is done by the pump manufacturers testing

17

## The npsha should be at least how much more than npshr?

### 10% higher

18

## What is another name for radial pumps?

### Centrifugal pump

19

## What creates the kinetic(speed,velocity) energy?

### The impeller

20

## Describe an axial pump

### There is no change in the direction of flow. It is also known as a propellor pump. They produce low discharge head, but large volume of flow.

21

## Describe a radial (centrifugal) pump.

### Discharge is perpendicular to the intake, has reasonably high discharge head.

22

## What is the only pump that has straight blades?

### High speed peripheral pumps. They can reach 25,000 rpm and head capabilities of 12,000 feet

23

## Where would you find a stripper?

### They are in a regenerative turbine pump, Inbetween the suction and discharge ports

24

## What is the most common centrifugal pump?

### Single stage, end suction pump.

25

## What is the benefit of the vertical single stage end suction pump?

### It saves space because pump can be incorporated in the piping

26

## What is benefit of a single stage double suction pump?

### It has a single suction inlet that then splits to allow flow to both sides. The opposing forces on either side cancel each other out, so it limits axial thrust.

27

## What pump handles the most amount of pressure?

### Multi stage barrel pumps. Handles pressures up to 6500 psi and 20,000 gpm. It has a double casing

28

## What are the three types of impellers?

### Open, semi open, closed

29

## What are the shaped lines running from the center outward on the back side of the impeller?

### Pump out vanes

30