Pumps

Front 1

Water sources that supply mains.

Back 1

• River Intakes.
• Impounding Resevoirs.
• Underground sources.

Front 2

Explain water distribution system.

Back 2

• Trunk main.
• Secondary main.
• Service main.
• Service reservoirs.
• Booster pumps.

Front 3

What do pressure and flow in a main depend on?

Back 3

• Diameter.
• Condition.
• Pressure.
• Length.

Front 4

BS750.

Back 4

• Should have FH or Fire Hydrant marked on the cover.
• Underside of cover should have 75mm diameter white plate with open and the direction written on.
• Outlet should have detachable 65mm diameter flanged round thread outlet made from gun metal.
• Outlet cap should be supplied and attached by a chain.
• The spindle should be provided with a cast iron cap - false spindle.
• Must close clockwise but open direction is permanently marked.
• Cast iron parts must be treated with an approved rust proofing.
• Should deliver 2000lpm and 1.7 bar.

Front 5

Groups of hose fittings.

Back 5

• Couplings.
• Branches and Nozzles.
• Branch holders, Radial branches and Monitors.
• Standpipes.
• Collecting head and suction hose fittings.
• Breechings.
• Adaptors.
• Miscellaneous hose fittings.
• Hose Ramps.

Front 6

7 characteristics of a good hose?

Back 6

• Flexible.
• Durable.
• Resistant to Rot.
• Change in Length and Diameter.
• Frictional Loss.
• Weight.
• Acceptance Test.

Front 7

State the purpose of branch and types of branch.

Back 7

A

Front 8

3 causes of damage to hose?

Back 8

• Abrasion.
• Shock.
• Contamination (acid, oil, grease, petrol).

Front 9

2 types of suction hose.

Back 9

• Partially Embedded.
• Smooth Bore.

Front 10

Define a pump.

Back 10

A pump is a machine driven by some external power for transmitting energy to fluids. This energy may be provided by the operators own efforts or by coupling the engine to a suitable engine or motor.

Front 11

Characteristics of a centrifugal pump.

Back 11

• At any given speed where there is no flow pressure is at a maximum.
• Pressure decreases as flow increases.
• When pump speed increases pressure and flow increase.
• When suction lift increases pressure and flow decrease.
• Flow is smooth at all settings.
• Can pump against closed deliveries.
• It needs a primer to get to work from open water.
• Small, light and compact relative to the output.

Front 12

3 types of gauges.

Back 12

• Bourdon tube (pressure).
• Diaphragm (compound).
• Flow meters.

Front 13

4 advantages of flowmeters.

Back 13

• Different flow for each delivery.
• No need to estimate pressure loss at the branch.
• No unexpected surges.
• Burst hose will be immediately apparent due to decreased flow at the branch.
• Open landing valves will be apparent by an increase in the flow at the flow meter.
• Closure of branch is immediately apparent, no reading at flow meter.
• Accurate assessments of water supply can be made.
• More efficient water relay.
• Fire ground calculations are not required.

Front 14

When operating from a pressure fed supply give 4 reasons for a loss of water supply.

Back 14

• Poor communication.
• Overdrawn supply.
• Damaged hose.
• Blocked pump eye.

Front 15

When working from a hydrant 4 reasons or an increase in delivery pressure.

Back 15

• Closing branch (flow meter zero).
• Debris or vehicle on delivery hose (flow meter zero).
• Kink in hose (flow meter reading reduced).
• Stones are blocking the nozzle (flow meter reading reduced or zero).
• Surge in mains pressure.

Front 16

Points to consider when working from open water.

Back 16

• Use the throttle carefully and feel the hose.
• Use collecting head for multiple supplies.
• Open delivery slightly before turning on a hydrant to allow air to escape and avoid excess pressure build up.
• Never operate the primer which can damage the main.
• Optimum delivery when compound gauge is close to zero.
• Close hydrants gently.
• Use flow meters.

Front 17

Maximum and Theoretical lift.

Back 17

Theoretical - 10m, Practical - 8-8.5m. Different because atmospheric pressure has to overcome CREST.

Front 18

Explain CREST.

Back 18

• Creating flow.
• Resistance.
• Entry loss.
• Suction lift.
• Temperature/Turbulence.

Front 19

Define a primer.

Back 19

A primer is a device for expelling air from the hard suction and pump casing so that atmospheric pressure will force water to the eye of the pump.

Front 20

Why a primer is only operated for 45 seconds.

Back 20

Either the lift is too great or there is an air leak on the suction side of the pump. Check for air leaks before trying again.

Front 21

13 reasons for no vacuum reading when working from open water.

Back 21

• Strainer not submerged - vortex.
• Loose coupling or faulty washer.
• Pump drain valve open.
• Delivery valve not seating.
• Air leak in suction hose.
• Defective gland seal.
• Leak in gauge pipe work.
• Defective exhaust valve in ejector primer.
• Defective drive to mechanically driven primer.
• Defective priming lever linkage.
• No water in water-ring prime.
• Compound gauge cock closed.

Front 22

Frictional loss laws.

Back 22

• Friction loss varies directly with the length of the pipe.
• For the same velocity, friction loss decreases directly with the increase in diameter.
• Friction loss increases directly with the square of the velocity.
• Friction loss increases with the interior roughness of the pipe.
• Friction loss, for all practical purposes, is independent of pressure.

Front 23

Pressure Laws.

Back 23

• Pressure is perpendicular to any surface which it acts.
• Pressure at any point of a fluid at rest is of the same intensity in all directions.
• Pressure applied from outside to a fluid contained in a vessel is transmitted equally in all directions.
• Downward pressure of a fluid in an open top vessel is proportional to the depth.
• The downward pressure of a fluid in an open top vessel is proportional to the density of the fluid.
• The downward pressure of a fluid on the bottom of a vessel is independent of the shape of the vessel.

Front 24

Explain jet reaction.

Back 24

When water is projected from a nozzle, a reaction equal and opposite to the force required to discharge the jet takes place at the nozzle, which tends to recoil in the opposite direction to the flow.

Front 25

Nozzle Discharge equation.

Back 25

L = ⅔ d2 √p

Front 26

Jet Reaction equation.

Back 26

R = 1.57 p d2
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