PP 009: Lifting From Open Water

Question 1

How many BAR is atmospheric pressure?

Answer 1

1 BAR

Question 2

What is the maximum theorirectal lift of water, in perfect conditions?

Answer 2

10m

Question 3

Practically, what is the maximum lift of water that can be achieved?

Answer 3

8m due to the factors of OFPITA

Question 4

What is OFPITA?

Answer 4

Overcoming inertia

Frictional loss

Pump entry loss

Imperfect vacuum

Temperature

Atmospheric pressure

Question 5

What does overcoming inertia mean?

Answer 5

Getting the water moving by adding kinetic energy

Question 6

Why does pump entry loss occur?

Answer 6

Due to the 90° angle at which the water enters the eye of the pump

Question 7

How does temperature affect the maximum lift of water?

Answer 7

The higher the temperature, the more difficult it will be to lift the water. Due to water starting to evaporate

Question 8

What is the name of the primer on all Mercedes appliances?

Answer 8

Automatic positive displacement reciprocating piston primer

Question 9

What equipment is used when lifting from open water?

Seven answers

Answer 9

Hard suction hose
Suction strainers
Strainer basket
Two suction wrenches
140-100mm adaptor
Short line
Salvage sheet

Question 10

What is the length and diameter of the hard suction hose?

Answer 10

2.44m

100mm diameter

Capable of withstanding external pressure

Question 11

What must be worn when working near water?

Answer 11

Full PPE and a personal flotation device (PFD)

Question 12

Should the tank to pump switch be open or closed when lifting from open water?

Answer 12

Closed

Question 13

What knots are used to secure the hard suction hose?

Answer 13

Clove hitch at the end with the strainer

Half hitches along the middle keeping it bent

Round turn and two half hitches at the appliance

Question 14

How deep should the strainer be to avoid a vortex forming?

Answer 14

300mm

Question 15

What does each -0.1 BAR represent on the compound guage?

Answer 15

1m of lift from open water

Question 16

What does an increase in the vacuum reading on the compound guage indicate?
Four answers

Answer 16

Level of supply dropped (if tidal)

Suction strainer blocked

Branches open

Burst delivery hose

Question 17

What would a decrease in the vacuum reading on the compound guage indicate?
Three answers

Answer 17

Level of supply raised (tidal)

Branches being shut down

Slight air leak in suction side of pump

Question 18

If the pump fails to achieve a lift, and there is a very high reading on the vacuum side of the compound guage, what could this indicate?
Two answers

Answer 18

Blocked suction strainer

Faulty suction hose