Lifting From Open Water

Question 1

Describe what is the maximum theoretical and practical lift from open water?

Answer 1

The maximum theoretical lift is 10 metres
However
Due to OFPITA
The maximum practical lift is 8 metres

Question 2

What is OFPITA?

Answer 2

• Overcoming inertia
• Frictional loss
• Pump entry loss
• Imperfect vacuum
• Temperature
• Atmospheric pressure

Question 3

How is a primer define?

Answer 3

A primer is defined as a device which can pump the air out of a centrifugal pump.

Question 4

What sort of primer does the appliance have?

Answer 4

An automatic reciprocating positive displacement piston primer.

Question 5

What equipment is used when lifting from open water?

Answer 5

• Lengths of hard suction
• Suction strainers
• Suction basket
• Suction wrenches
• 140mm-100mm adaptor
• Short line
• Salvage sheet

Question 6

What are some of the practical and safety considerations of lifting from open water? Name 5

Answer 6

• All staff working near water must be made aware of the danger and use appropriate PPE- life jackets, safety lines, etc.
• Make sure appliance is on safe ground
• Make allowance for tidal flow
• At night set up lighting
• Hazards of open water- Water borne diseases

Question 7

Where is the measured from as indicated on the compound gauge.

Answer 7

The lift is measured from the level of the water to the eye of the pump.

Question 8

What does an increase in the vacuum reading on the compound gauge indicate?

Answer 8

An increase indicates the pump is working harder.
Level of supply dropped (tidal or water source used up)
Suction stained blocked
Branches opened
Burst delivery hose

Question 9

What does an decrease in the vacuum reading on the compound gauge indicate?

Answer 9

An increase indicates the pump is working less.
Level of supply raised (tidal)
Branches shut down
Slight air leak on suction side of pump

Question 10

If the pump fails to achieve a lift and there is no reading on the vacuum side of the compound gauge the following causes are to be checked?

Answer 10

Suction strainer not adequately submerged
Loose/ faulty suction joints
Open drain cock/ loose drain plug in pump casting
Delivery valve not seating correctly
Air leak in suction hose
Defect seal
Serious leaking in pipes lead in to gauge
Compound gauge damper closed. Gauge showing no vacuum reading although pump has primed