Transcript
Pump types and theory
Types of pumps
• There are three main types that will be covered;– Rotary gear– Rotary vane– Centrifucal
• Centrifucal pumps are the most common type of pump found today, we will go into its use in depth
Rotary Gear Pumps
• Rotary pumps work by using tight tolerance gears to push water
• Tolerances are so tight that this pump will pump air
Rotary Vane Pumps
• These pumps work like the rotary gear pumps, but have vanes that can extend and retract
• This pump resists the effects of wear much better
Parts of the centrifical pump
Throttle controls the rotation speed of the impellor. More throttle = more pressure
How the centrifical pump works
How the centrifical pump works
How a centrifical pump works
Water supply for the pump
Booster tank
Intake from steamers and 2 ½
Tank to pump
Tank fill
Water being supplied to steamer intake into pump, flowing discharges and filling tank at the same time
Two stage pumps
two stage pump in volume
Two stage pump in pressure
Discharge Manifold• The water being
discharged from the pump is forced into a manifold; the junction for all discharge lines
• The manifold has all of the discharge valves that are controled from the pump panel
Using the relief valve
Relief Valves areUsed to sharp increases in pressure from going all the way through the attack lines and harming the nozzle crew
Excess pressure is dumped into the intake side of the pump
Using the relief valve
Using the relief valve
Centrifucal Pump Problems
• There are several conditions that can reduce the life or destroy the pump;– Running the pump with nothing flowing
or circulating– Cavitating the pump– Running the pump dry
Pump Running, but not Discharging
• Water that is held in closed lines and in the pump will be warmed by the friction of the running pump
• If let go long enough, the water can boil and cavitate the pump
• Check to see if your hoselines are warm or hot
Pump Cavitation• This occurs when
there is too much air in the pump, or there is more water being discharged than is coming into the pump
• Sounds like gravel rolling around on the inside of the pump casing
Running the Pump Without Water
• Pumps need the water for cooling, lubrication, and to swell the packing
• Without water in the pump, the heat from friction will quickly destroy a pump
Conclusion
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