14-06-2012, 12:27 PM
SEMINAR ON PUMP OPERATOR PROGRAM
PUMP OPERATOR PROGRAM.ppt (Size: 448.5 KB / Downloads: 42)
Centrifugal Pump
Non-positive displacement pump
Three factors influence pump discharge pressure
1) Incoming pressure, 2) Speed of the impeller, and 3) The amount of water being discharged
Single or multi-stage
NOT self-priming
Cavitation
Pressure Relief Valve/Governor
Most common devices
Set while discharging at operating pressure
Set for highest operating pressure
Pressure relief valve - diverts water
Pressure governor - controls rpm
Intake Relief Valve
Also known as dump valve
Protects pump from water hammer and excessive intake pressure
Possibly capped during high pressure operations
Piston intake relief valve.
Manual Pump Shift
Provides back-up
Usually located on pump panel
Often require two persons to operate
Back-up throttle may have to be used
Exercise manual shift often
Water System Consumption
Peak use hours
Morning - residential areas
Mid day - downtown areas
Evening - residential areas
May contact Water Department to divert water to fire area
Pressure and Fluids
Pressure acts on fluids according to six basic principles
Fluid pressure is perpendicular to any surface on which it acts.
Fluid pressure at a point in a fluid at rest is of the same intensity in all directions.
Pressure applied to a confined fluid from without is transmitted equally in all directions.
The pressure of a liquid in an open vessel is proportional to its depth.
The pressure of a liquid in an open vessel is proportional to the density of the liquid.
The pressure of a liquid on the bottom of a vessel is independent of the shape of the vessel.
Friction Loss
The part of the total pressure lost while forcing water through pipe, fire hose, fittings, adapters, and appliances. The basis for fire hose friction loss calculations are the size of the hose, the amount of water flowing, the length of the hose lay, the age of the hose, and the condition of the lining.