1. Service Delivery 3
Pumps

2. Aims
To provide students information about fire service pumps and their operation

3. Learning Outcomes At the end of the session students will be able to:
Detail the requirements of a fire service pump
Describe how a centrifugal pump works
Describe how a peripheral pump works
Detail the operating principles of an ejector pump
continued…

4. Detail the operating principles of priming devices used within the brigade
Describe the operating principles of pressure and compound gauges
List the considerations to be taken into account when carrying water
List the considerations to be taken into account when relaying water.

5. Types of pumps POSITIVE - Displace both liquids and gases
NON-POSITIVE - Displace only liquids a
separate primer being
required to remove the air
from the system.

6. Requirements of a pump A fire service pump must be; Self-contained
Light in weight
Able to handle large quantities of water
Able to produce fairly high pressures
Reliable
Easy to operate and maintain.

7. Non-positive displacement pumps
Centrifugal pumps
Peripheral pumps.

8. Centrifugal pumps Consist of; Spinning part called the impeller
Casing called the volute.

9. impeller
volute
Water inlet.

10. Purpose of the volute
To channel water from the periphery to the outlet
Reduce water velocity and turbulence
Increase the water pressure.

11. volute
impeller
water inlet
Guide vanes.

12. Characteristics of centrifugal pumps
At any given speed where there is no flow pressure is at a maximum
Pressure decreases as the delivery valves are opened and the flow increases
When pump speed increases pressure and flow increase
When suction lift increases pressure and flow decrease.

13. Advantages of centrifugal pumps
Simple maintenance
Can be run against closed deliveries without damage
Light and compact relative to their output
Can be driven directly from an internal combustion engine.

14. Velocity and pressure changes within a centrifugal pump.
Suction hose
impeller
volute

15. Increasing pump pressures
This can be done in a number of ways;
Increasing the size of the impeller
Increasing the speed of the impeller
Increasing the number of impellers (as in a 2-stage or multi-stage pump)
Using a peripheral pump.

16. Peripheral pump.

17. Operating principles.

18. The peripheral pump Advantages;
Can produce high pressures at relatively low running speeds,saving on wear & tear
Can be mounted on the same shaft as the centrifugal pump
Ideally suited for use with high pressure hose reels.

19. The Godiva UMPX pump.

20. Power take off (PTO)
Directs engine power away from the road wheels to drive another piece of equipment, such as the fire pump.

21. Cooling systems
During pumping operations some water is taken from the high pressure side of the pump to a heat exchanger where it assists in cooling the engine
The water then flows back to the low pressure side of the pump.

22. Priming There are three ways to prime a centrifugal pump;
Use of a gravity fed supply
Via a pressure fed supply
By using a priming device to remove air from the pump.

23. Function of a primer
Used where a static water supply is lower than the pump
The primer removes air from the pump and creates a partial vacuum allowing atmospheric pressure to effectively force water up the hard suction into the pump.

24. Water ring primer.
Rotating impeller
Outlets
Inlet from pump

25. Water ring primer.
Ring of water
Oval housing
Low pressure

26. Water ring primer. Air rushes in from pump
Air is forced out of the primer

27. Operating principle of the ejector pump.
Venturi effect
Surrounding fluid
Fluid & propellant
Throat
Jet

28. Hughes-Noble ejector pump.
propellant
throat area

29. Lightweight pump.

30. Exhaust gas ejector.

31. Exhaust gas ejector.

32. Gauges Pressure gauge Compound gauge Tachometer Water tank contents
Oil pressure gauge
Fuel tank contents
Engine coolant temperature.

33. Typical gauge group.

34. Pressure gauges Low pressure gauge High pressure gauge.
Showing the output pressure of the pump;
Low pressure gauge
High pressure gauge.

35. Bourdon tube gauges.

36. Compound gauges Show the inlet pressure of the pump
The reading may be positive if supplied from a hydrant or negative when lifting from open water.

37. Compound gauges.

38. Compound gauge.

39. Brass housings.
Rear Housing
Front Housing

40. Rear Housing
Front Housing.

41. Vacuum.

42. Positive Pressure.

43. Compound gauge.

44. Negative readings
A negative reading of 0.1bar would indicate a lift from open water of approximately 1metres
A reading of 0.4bar would indicate a lift of 3 metres allowing for practical considerations.

45. Water carrying Used where the water requirement is relatively limited
When the distances between the water source and fireground may be considerable.

46. Water relaying.

47. Distances between pumps
Depends on;
The flow required
Pump pressure used
Contours of the relay route
Size, type and number of hose lines
If the pump is lifting water as well as delivering.

48. Confirmation Assessments will be based on this lesson and the corresponding study note
Learning Outcomes
Detail the requirements of a fire service pump
Describe how a centrifugal pump works
Describe how a peripheral pump works
Detail the operating principles of an ejector pump
continued…

49. Detail the operating principles of priming devices used within the brigade
Describe the operating principles of pressure and compound gauges
List the considerations to be taken into account when carrying water
List the considerations to be taken into account when relaying water.

50. THE END