1. Operating Fire Pumps Sugar Land Fire Department Driver/Operator—Pumper Academy Spring 2003

2. Operating Fire Pumps

3. Making the Pump Operational The process of making the fire pump operational is also referred to as putting the pump into gear The process for making the fire pump operational begins after the apparatus has been properly positioned and the parking brake has been set. After properly positioning the apparatus and setting the parking brake, on the majority of apparatus, the remainder of the procedure for making the fire pump operational takes place before the driver./operator exits the cab.

4. Making the Pump Operational Once the driver/operator exits the cab, the next step, in all cases except when the apparatus is used for pump-and-roll operations, should be to chock the apparatus wheels Tests have indicated that the apparatus may override the parking brake system at engine speeds as low as 1300 rpm. The procedure for making the pump operational varies depending on the type of pump drive and the type of pump drive and the manufacturer of the apparatus.

5. Negative Pressure Step 1: water enters the pump under pressure from the source Step 2: As the discharge pressure from the fire pump increases, the incoming pressure from the supply source drop due to friction loss in the water system. Step 3: If the discharge pressure is increased too much, the intake pressure from the supply source may drop below 0 psi

6. Why it’s bad… Hydrant source Increases possibility of damage to the fire pump and water system due to water hammer if the flow is cut off suddenly Can damage water heaters or other domestic appliances on a municipal water supply system Pumper Source Can damage the pump through cavitation Can cause supply hose to collapse, resulting in interruption of water supply

7. Hydrant Selection Hydrant closest to the fire is not always the best choice. Best hydrants are located on large water mains arranged in a grid pattern so that they can receive water from several directions at the same time. Worst hydrants typically are those located on dead end mains Single lines used to supply relatively small amounts of water may be partially clogged, which further reduces their capacity.

8. Hydrant Flow Using general knowledge of water distribution systems Accessing water department records for hydrants in the jurisdiction Checking the pre-incident plans Receiving the information through the computer dispatch system Consulting map books for hydrant information and locations while en route to the scene

15. Forward & Reverse Lays When using 2 ½ or 3 “ hoselines to supply the pumper directly off hydrant pressure, lines should be no longer than 300 feet. When using 2 ½ or 3” hoselines to supply the pumper directly off hydrant pressure, lines may be somewhat longer than 300’ if the hydrant is on a special high-pressure main. Many departments prefer that four-way hydrant valves be used to aid the forward lay process. When making a forward lay, it is recommended that gate valves be attached to unused hydrant discharges.

16. Forward & Reverse Lays A reverse lay is used so that a size-up can be made before laying a supply line The reverse lay is the most expedient way to lay hose if the apparatus that lays the hose must stay at the water source If threaded couplings are used, hose beds set up for reverse lays should be loaded so that the first coupling to come off is male.

17. Forward & Reverse Lays The reverse lay has become a standard method for setting up a relay pumping operation when using medium diameter hose as a supply line A disadvantage of the reverse lay for single engine company operations is that the initial attack is delayed because essential fire fighting equipment must be removed and placed at the fire location before the pumper can proceed to the water source. The reverse lay obligates the pump operator to stay with the pumper at the water source

18. Forward & Reverse Lays When reverse laying a supply hose, it is not necessary to use a four-way hydrant valve. The reverse lay is used when the first pumper arrives at a fire and must work alone for an extended period of time: the laid hose becomes an attack line.

20. Pump Overheating Pull some of the booster line off the reel, securely tie off the nozzle to a solid object, open the reel supply valve, and discharge water in a direction that will not harm people or damage property. Open a discharge drain valve Partially open the tank fill valve or pump to tank line Use a bypass or circulator valve if the apparatus is so equipped.

21. Static Water Source In most cases, the static water supply will be located at a lower level than the fire pump. Pressure differential allows atmospheric pressure acting on the surface of the water to force water into the fire pump To create a pressure differential, an airtight, noncollapsible waterway is needed between the fire pump and the body of water to be used. The amount of friction loss in the hard intake hose depends upon the diameter of the hose

22. Static Water Source It is possible to increase the capacity of the pump by increasing the intake hose diameter. The total pressure available to overcome drafting pressure losses is limited to the atmospheric pressure at sea level—14.7psi Atmospheric pressure decreases 0.5psi for each 1,000’ of elevation Increasing the height of the lift decreases total pump capacity. The vacuum reading on the master intake gauge provides an indication of remaining pump capacity

23. Static Water Source Most pumps develop a maximum vacuum of approximately 22 inches of mercury Cavitation occurs when the driver/operator tries to increase the discharge from the pump beyond the point of maximum vacuum on the intake. Cavitation is defined as a condition where, in theory, water is being discharge from the pump faster than it is coming in.

24. Static Water Source Cavitation often results when a pump has been equipped with inadequate piping from the water tank. Cavitation occurs most often during drafting operations.

25. Cavitating Pumps Hose streams will fluctuate. Pressure gauge on the pump will fluctuate Popping or sputtering may be heard as the water leaves the nozzle. The pump itself will be noisy, sounding like gravel is passing through it. There will be a lack of reaction on the pressure gauge to changes in the setting of the throttle.

26. Selecting Drafting Sites Most important factor in the choice of the draft site is the amount of water available. In order for a pumper to approach its rated capacity using a traditional strainer, there should be a minimum of 24 inches of water over the strainer.

28. If there is not an adequate amount of water above the strainer, the rapid movement of the water into the intake strainer creates a whirlpool. A disadvantage of the floating strainer is that it is limited to taking water in on only one side, which may limit the ability of the pumper to reach its rated discharge capacity. Low-level strainers are designed to sit directly on the bottom of the tank or pool and are capable of allowing water to be drafted down to a depth of about 2 inches.

29. Water that is below 35*F or above 90*F may adversely impact the pump’s ability to reach capacity Pumping nonpotable (untreated) water can be harmful to the pump The most common type of pump contamination, and possibly the most damaging, is dirty or sandy water Atmospheric pressure must overcome elevation pressure as well as friction loss in the intake.

31. Causes of Inability to Prime Air leak that prevents the primer from developing enough vacuum Insufficient fluid in priming reservoir Too low engine speed Too high lift High point in hard intake hose creating an air pocket

32. Problems During Drafting Air leak on intake side of pump Whirlpool allowing air to enter pump Air leakage due to defective packing in pump

33. Sprinkler & Standpipe The water supply for sprinkler systems is designed to supply only a fraction of the total number of sprinklers actually installed on the system If a large fire should occur, or if a pipe breaks, the sprinkler system will need an outside source of water and pressure in order to do its job effectively. Included in the pre-incident planning information should be the location of the fire department connection (FDC), the nearest hydrant or water supply source to the FDC, and any special requirements for pump pressure required to supply the system

34. Sprinkler & Standpipe Sprinkler FDCs consists of a siamese with at least two 2 ½” female connections or one large diameter sexless connection that is connected to a clappered inlet. If there is nay indication of an actual fire, a minimum of two 2 ½” hoseline or one 3” hoseline should be connected to the fire department connection. It is a general rule of thumb that one 1,000 gpm rated pumper should supply the FDC for every 50 sprinklers estimated to be flowing

35. Sprinkler & Standpipe In most cases, it is desirable to confirm the presence of fire before pumping into the system Multistage pumps should be in the VOLUME (PARALLEL) position. If recommended discharge pressure is not on the FDC plate or in the pre-incident planning information, the general rule of thumb is to discharge 150 psi into the FDC.

36. Sprinkler & Standpipe Standpipes are used to speed fire attack in multistory or single-story structures with large floor area. Generally, fire department attack lines--not the house or standpipe lines—should be used for fire attack from standpipe systems Standpipes may be wet or dry, depending upon owner preference or local code requirements Wet-pipe systems contain water under pressure and are ready to be used as soon as lines can be attached to the outlet.

37. Sprinkler & Standpipe Dry-pipe systems must be supplied with water from a pumper that attaches to a standpipe FDC outside the building Standpipe FDCs should be clearly identified to prevent confusion between sprinkler and standpipe connections. Wet standpipes are also supplied through an outside FDC with water under pressure to supplement the system’s water supply. To allow for more accurate hydraulic calculations, the driver/operator should be familiar with the hose and nozzles used in high-rise packs carried to the fire floor by firefighters.

38. Sprinkler & Standpipe Add approximately 5 psi to the desired nozzle pressure for each floor above the standpipe connection that will have operating fire streams Pump discharge pressures in excess of 200 psi are not encouraged unless the standpipe system has been designed to withstand higher pressures. If the standpipe system is equipped with pressure reducing valves, the driver/operator bases elevation pressure on the total height of the standpipe or zone being used.

39. Sprinkler & Standpipe Frequently, vandals or curious individuals may open the hose valves in dry standpipes and leave them in an open position. If a firefighter is not sent down the stairs to close the valves, when the standpipe is charged, water will discharge on levels below the fire floor. Often when dry standpipes are charged, there will be a time delay before the delivery of water to the hose valve because of the amount of air that must be expelled from the system.

40. Factors Determining Pressure Friction loss in the standpipe Friction loss in the hose lay from the pumper to the FDC Friction loss in the hose on the fire floor Nozzle pressure for the type of nozzle employed Elevation pressure due to the height of the building.

41. Standpipe Impairments FDC connection has a frozen swivel FDC unusable because of vandalism Individual hose valve on an upper floor is found inoperative Single-riser building where the standpipe is totally unserviceable