Presentation is loading. Please wait.

Presentation is loading. Please wait.

Intermediate SFFMA Objectives: – Hrs received

Similar presentations


Presentation on theme: "Intermediate SFFMA Objectives: – Hrs received"— Presentation transcript:

1 Intermediate SFFMA Objectives: 24-02.01 – 24-02.11 8Hrs received
Pump Operations Intermediate SFFMA Objectives: – 8Hrs received

2 SFFMA Objectives Trainee shall identify the type, design, operation, nozzle pressure and flow in GPM of various types of nozzles. Trainee shall list the different types of fire streams. Trainee, given a 2½ inch straight stream nozzle, shall demonstrate the proper opening and closing techniques and line movement procedures. Trainee shall calculate nozzle reaction for various nozzle pressures. Trainee, given the proper information, shall list advantages and disadvantages of various nozzles: A. straight stream B. fog C. master stream Trainee shall define water hammer and list ways of preventing water hammer. Trainee shall calculate the water flow rate needed to control fire in a room that is 20'x20'x 8'. Trainee, given a diagram of various nozzles, shall list major parts and trace flow routes through each. Trainee shall list factors that influence fire steams. Trainee shall list the proper procedures for inspection and maintenance of fire fighting nozzles. Trainee shall demonstrate the operations of the pumper pressure relief system and/or pressure control valve as follows: A. Trainee, given a pump panel, shall identify a pressure relief system. B. Trainee shall list the reasons a pressure relief system is used. C. Trainee shall list the different types of pressure relief systems used in the fire service. D. Trainee shall list three (3) reasons of how excessive pressure develops in fire hose.

3 NOZZLE REACTION Counterforce directed against a person holding a nozzle or a device holding a nozzle by the velocity of water being discharged. Measured in pounds Nozzle reaction formulas NR= 1.57·d²·NP and NR= ·Q·NP

4 Fire Stream Classifications
Low-volume stream Handline stream Master stream Firefighter I

5 Fire Stream Considerations
Volume discharged determined by design of nozzle, pressure at nozzle To be effective, stream must deliver volume of water sufficient to absorb heat faster than it is being generated (Continued) Firefighter I

6 Fire Stream Considerations
Type of fire stream indicates specific pattern/shape of water stream Requirements of effective streams Requirements of all streams Firefighter I

7 Solid Stream Produced from fixed orifice, solid-bore nozzle
Has ability to reach areas others might not; reach affected by several factors Design capabilities (Continued) Firefighter I

8 Solid Stream Velocity of stream a result of nozzle pressure
Nozzle pressure, size of discharge opening determine flow Characteristics of effective fire streams Flow rate Firefighter I

9 Advantages of Solid Streams
May maintain better interior visibility than others May have greater reach than others Operate at reduced nozzle pressures per gallon (liter) than others May be easier to maneuver (Continued) Firefighter I

10 Advantages of Solid Streams
Have greater penetration power Less likely to disturb normal thermal layering of heat, gases during interior structural attacks Less prone to clogging with debris (Continued) Firefighter I

11 Advantages of Solid Streams
Produce less steam conversion than fog nozzles Can be used to apply compressed-air foam Firefighter I

12 Disadvantages of Solid Streams
Do not allow for different stream pattern selections Provide less heat absorption per gallon (liter) delivered than others Hoselines more easily kinked at corners, obstructions Firefighter I

13 DISCUSSION QUESTION What type of fire situation would be ideal for a solid-stream nozzle? Firefighter I

14 Fog Stream Fine spray composed of tiny water droplets
Design of most fog nozzles permits adjustment of tip to produce different stream patterns (Continued) Firefighter I

15 Fog Stream Water droplets formed to expose maximum water surface for heat absorption Desired performance of fog stream nozzles judged by amount of heat that fog stream absorbs and rate by which the water is converted into steam/vapor (Continued) Firefighter I

16 Fog Stream Nozzles permit settings of straight stream, narrow-angle fog, and wide-angle fog Nozzles should be operated at designed nozzle pressure (Continued) Firefighter I

17 Fog Stream Several factors affect reach of fog stream
Interaction of these factors on fog stream results in fire stream with less reach than that of straight or solid stream (Continued) Firefighter I

18 Fog Stream Shorter reach makes fog streams less useful for outside, defensive fire fighting operations Well suited for fighting interior fires Firefighter I

19 Fog Stream: Waterflow Adjustment
Two types of nozzles control rate of water flow through fog nozzle Manually adjustable nozzles Automatic nozzles Firefighter I

20 DISCUSSION QUESTION How should adjustments to the rate of flow be made? Firefighter I

21 Fog Stream: Nozzle Pressure
Combination nozzles designed to operate at different pressures Designated operating pressure for most combination nozzles is 100 psi (700 kPa) (Continued) Firefighter I

22 Fog Stream: Nozzle Pressure
Nozzles with other designated operating pressures available Setbacks of nozzles with lower operating pressures Courtesy of Elkhart Brass Manufacturing Company. Firefighter I

23 Advantages of Fog Streams
Discharge pattern can be adjusted for situation Can aid ventilation Reduce heat by exposing maximum water surface for heat absorption Wide fog pattern provides protection to firefighters Firefighter I

24 DISCUSSION QUESTION What type of fire situation would be ideal for a fog-stream nozzle? Firefighter I

25 Disadvantages of Fog Streams
Do not have as much reach/penetrating power as solid streams More affected by wind than solid streams May disturb thermal layering May push air into fire area, intensifying the fire Firefighter I

26 Water Hammer Water moving through a pipe or hose has both weight and velocity. The weight of water increases as the pipe or hose size increases. Suddenly stopping water moving through a hose or pipe results in an energy surge being transmitted in the opposite direction, often at many times the original pressure. This surge is called Water Hammer 200 PSI x 7 = 1400 PSI or 1400 pounds of pressures returning, finding the weakest spot in the system and breaking it. This could be the pump, hose, nozzle, pump piping, supply line, or water main.

27 WATER HAMMER Force created by the rapid acceleration or deceleration of water. It generally results from closing a valve or nozzle too quickly. Can be up to seven (7) times the original pressure.

28 [Tell any water hammer stories if you have them.]

29 GAUGES Master Intake gauge (Compound) Master Discharge gauge
Discharge gauge (individual gauges) Oil Pressure Voltmeter Tachometer (engine RPM) Pump overheat indicator Engine coolant temperature gauge The master intake and discharge gauges are the two primary gauges used to determine the water pressure entering and leaving the pump.

30 Master Intake Gauge Measures positive or negative pressure
Calibrated from 0 to 600 PSI (usually) for positive and from 0 to 30 inches of vacuum for negative pressure Provides indication of residual pressure from a hydrant or relay operation Provides indication of maximum capacity of pump when at draft Commonly referred to as compound or vacuum gauge Usually calibrated from PSI positive pressure and 0-30 inches of vacuum on the negative side Obtain residual pressure with this gauge

31

32 Master Discharge Gauge
Measures positive pressure Calibrated from 0 to 600 PSI Up to 1000 PSI on special pumpers Measures pressure as it leaves the pump and before it gets to the individual gauges Always reads the highest pressure the pump is producing May differ from individual gauge in relation to PSI, individual more reliable for specific line

33

34 Discharge Gauge Individual gauges measure the pressure for each individual discharge. Use these gauges not the master discharge gauge when flowing any line.

35 Oil Pressure Gauge Measures oil pressure of the motor.
Normal operating pressures vary with different brands of apparatus. Variations from normal may indicate pending problems. Shows that an adequate supply of oil is being delivered to the critical areas of the engine It is not a measure of the oil in the crankcase

36 Voltmeter Provides a relative indication of battery condition and alternator output by measuring the drop in voltage as some of the more demanding electrical accessories are used. Indicates the top voltage available when the battery is fully charged. Measures drop when electrical demand is high.

37 Tachometer Records the engine speed in revolutions per minute (rpm)
It can give valuable information about the condition of the pump. May refer to the acceptance test rating panel to check on pump efficiency (identification plate on the pump panel)

38 Pump Overheat Indicator
Audible or visual indicator * Overheating occurs when the pump impeller is spinning, for prolonged periods, but no water is being discharged Warning indicators can be flashing lights or an audible alarm. Not standard equipment, must be ordered for pump panel. New Houston Fire Department E-1 pumpers have a TRV or Temperature Relief Valve. This valve is a “gel” type. When the gel heats to 120ºF the valve opens slowly and lets out a stream of water underneath the pumper. This assists in keeping the pump from overheating, but does not eliminate it from occurring. The gel keeps the valve from opening and closing quickly. The operator of the pump must discharge or flow water constantly to keep the pump from overheating and damaging the fire pump.

39 Pump Overheat Best place to check for overheat is right here
Best way to never overheat the pump is to always be moving water. Place your hand on the large intake pipe. If it is warm or not cool to the touch, then the pump is too HOT! Discharging water is the only way to cool it down. Open the tank fill valve or open a discharge and flow water on the ground.

40 Engine Coolant Engine coolant temperature gauge
Shows the temperature of the engine coolant - the normal operating range of the Detroit Diesel Series 60 Engine is between 192° - 205° Fahrenheit Caution: An engine that operates too cool is not efficient. An engine that has an operating temperature that is too high may be damaged.

41 Cavitation Firefighters definition: Cavitation:
Water is discharged from the pump faster than it is coming in. Cavitation: A condition in which vacuum pockets form in the pump and causes vibrations, loss of efficiency, and possible damage.

42 Cavitation During Cavitation:
The pressure at the eye of the impeller falls below normal atmospheric pressure. The water boils faster at temperatures less than normal atmospheric pressure. Steam and air bubbles are created. The air bubbles move outward in the impeller and into the high-pressure zone. The air bubbles collapse, producing noise and vibration. Cavitation has a cumulative effect. Cavitation of the pump each time it is used it will eventually eat away, or destroy the pump impeller.

43 Cavitation To Avoid Cavitation:
Intake pressure from pressurized sources should not drop below 20 psi. Cavitation can be recognized by the fact that increasing the engine rpm does not result in an increase in discharge pressure.

44 PRESSURE RELIEF SYSTEMS
Intake Pressure Relief Valves Pressure Relief Valves Pressure Governors

45 Intake Pressure Relief Valves
Piston intake relief valves decrease the potential for a water hammer. Two types of pressure relief devices: Piston intake relief valve Dump valve (on pump) Should be 100 PSI Can be set from 50 to 175 PSI Two types of piston intakes Harrington uses set screw to adjust setting (Allen wrench is needed) and has a chart (on the intake) to refer to when setting relief pressure. Elkhart uses 7/8 adjustment bolt to adjust setting and has to be adjusted while under pressure.

46 Intake relief valves-dump valves
Relieves pressure from incoming supply lines, before it goes into the pump.

47 Pressure Relief Valves
Waterous PRV Hale PRV

48 Pressure Relief Valves
Pressure relief valves must be set while pumping the desired pressure with water flowing. Must be set at highest pressure necessary (gate back other lines). Pressure relief valves do not provide cavitation protection.

49 Pressure Relief Valves
They prevent an excessive amount of pressure being transferred to another line. Engine rpm will not fluctuate as lines are opened or closed. Pressure Relief Valves divert water internally. PRVs send water and the excess pressure from the discharge side back to the intake side. PRVs do not respond rapidly. They may take several seconds to react.

50 Relief Valve Operation

51 Manual Throttle Operated via a cable to the fuel system.
CCW to increase and CW to decrease speed. Red button in center is the Emergency Shut-Down. Do not use the Emergency button for routine shut downs, as it may break the cable or pump parts. Manual back-up throttles generally are of this type.

52 Pressure Governors Pressure governors regulate engine pressure by adjusting engine rpm to compensate for attack lines being opened or shut. This prevents an excessive amount of pressure being transferred to another line. Engine rpm will fluctuate as lines are opened or closed. PGs can respond rapidly to pressure changes.

53 Pressure Governors Pressure governors must be set while pumping the desired pressure. Must be set at highest pressure necessary (gate back other lines) Pressure governors provide cavitation protection. If the pressure governor senses an increase in rpm without a corresponding increase in pressure, the engine will return to idle after 3-5 seconds.

54 Electronic Pressure Governor
Seagraves version

55 Electronic Pressure Governor
Quality version

56 Electronic Pressure Governor
Detroit Diesel Fire commander On all E-One Fire Apparatus

57 Practical Exercise Firefighter shall:
Identify the type, design, operation, nozzle pressure and flow in GPM of various types of nozzles Fog Straight Stream Master Stream Given a 2 ½’’ straight stream nozzle, shall demonstrate the proper opening and closing and line movement procedures


Download ppt "Intermediate SFFMA Objectives: – Hrs received"

Similar presentations


Ads by Google