Equipment Flashcards
This may be happening if the pump sounds like it is pumping “rocks” or make a pinging sound.
The pump may be cavitating
Surrounds the pump impeller.
Volute case
Used to remove calcium deposits on hypochlorinator equipment.
Acid solution
Apparatus used to measure the flow rate from a fire hydrant.
Pitot meter
Basic unit of electrical power.
Watt
Electricity:
- Current flow
- Electrical potential
- Amps or amperes (The symbol for amps is “I”)
- Volts or voltage (The symbol for volts is “E”)
Location of chlorine cylinder fusible plug.
- 150 lb cylinder: In the cylinder valve.
- 1-ton cylinder : Three plugs are located on each end of the cylinder
This should be replaced every time a chlorine cylinder is changed.
Washer
This is the change in flow when a second identical pump is turned on, and pumps into a common header.
The flow will increase, but never equal twice the capacity of the single pump
Intersection of the pump head-capacity curve (H-Q curve) and the system curve.
Pump operating point
The point on a pump performance curve (H-Q curve) where the efficiency is highest.
Best efficiency point (BEP)
The schedule rating on plastic pipe is an index of this.
Pipe wall thickness
Initial signs of failure in a gear drive mechanism.
- Noise
- Vibration
- Excess heat
Throttling (partially closing) the discharge valve on a pump may stop this.
Cavitation
Misalignment of the motor and pump shafts can result in this.
Vibration and premature failure of the pump and/or motor bearings
Over lubrication of the pump motor can result in this.
Bearing failure
these conditions can cause a centrifugal pump to discharge at a reduced rate.
- Plugged or worn impeller
- Wrong impeller speed
- Partial plug on suction or discharge side of pump
Gate valves are designed to operate in these positions.
Fully opened or fully closed
These devices are designed to measure the water production at a treatment plant.
- Venturi meter
- Orifice plate meter
- Propeller meter
- Pitot meter
Unit installed in a pump stuffing box, to control leakage around the pump shaft. Typically includes rotating carbon and stationary ceramic components.
Mechanical seal
Amperage draw on a centrifugal pump motor as the pump discharge valve is closed.
the amperage draw will go down
Rapid closing or opening of a valve can cause this problem.
Water hammer
Principle of operation of a reduced pressure backflow assembly (RPBA)
Water will not flow from a zone of low pressure to higher pressure
Problems associated with pump cavitation.
- Pitting damage to the impeller and pump volute case
- Poor pump efficiency
Materials used as the “sacrificial anode” in cathodic protection of steel tanks and pipes.
Magnesium or Zinc
Symptoms of a plugged gas chlorine injector head.
- The chlorine flow is zero
- The chlorine cylinder pressure is normal
- The vacuum is low
Tubercle or scale deposits in a distribution system piping can do this to the Hazen and Williams roughness coefficient (“C” value) for the pipe.
The Hazen and Williams “C” actor would be lowered
Corrosion that occurs due to the contact of dissimilar metals.
Galvanic corrosion
Build-up of oxide deposits in steel or iron pipes.
Tuberculation
Failure of hypo-chlorinator could result from this condition.
Build-up of deposits within the hypo-chlorinator
Temperature that melts the chlorine cylinder fusible plug.
Approximately 158º F
“Rule-of-thumb” for maximum daily removal of chlorine from a cylinder.
- 150 lb cylinder
- 1-ton cylinder
Approximately 1/4 of the full tank net weight per 24 hours
(or)
- 40 lb/day for 150 lb. cylinders
- 400 lb/day for 1-ton cylinders
Loss of vacuum to a gas chlorinator could be caused by these problems.
- Plugged injector head
- Loss of water flow to the injector head
Check valve used to maintain centrifugal pump prime.
Foot valve
Rotating component in a centrifugal pump that imparts pressure and flow to the water.
Impeller
“Rule-of-thumb” for leakage pump packing.
One drip per second for each inch of shaft diameter
The function of a pump lantern ring.
Distribute seal water to the pump packing
This can be done to change the rotation direction of a three phase pump motor.
Switch any two of the three motor leads
Amp readings when three phase motor operates under single phase.
Amperage in one leg is very high, and the amperage on the other two legs is zero
When one leg of three phase power is lost, the motor does this.
“Single phasing”
Pumps that discharge into a common header pipe.
Operating in parallel
Provides proper tension on a pump packing to control leakage rate.
Packing gland
Function of a seal water supplied to the stuffing box of a centrifugal pump.
- Cools packing and shaft
- Lubricates shaft
- Flushes grit and other debris away from the shaft
Changes in pump impeller speed have these effects:
- Pump capacity (gpm output)
- Pump total head
- Pump horse power
- Flow increases in direct proportion to the change in speed
- Total head (TDH) increases in proportion to the square of the change in speed
A gauge on the suction side of an operating centrifugal pump measures this.
Dynamic suction head or lift
A gauge on the discharge side of an operating centrifugal pump measures this.
Dynamic discharge head or lift
This can protect steel tanks and pipes from corrosion.
Cathodic protection, using magnesium or zinc as a sacrifical metal
Air leaking into suction piping of a centrifugal pump can cause these problems.
- Loss of prime
- Air lock of the pump
Pump cavitation is caused by these conditions.
- Too high suction lift
- Plugged suction line
- Too high pump speed
- Warm water temperature
- Throttled suction valve
- Significant drop in pump discharge head
Materials used for pump packing.
- Jute
- Hemp
- Cotton
- Teflon
- Graphite
Lubrication materials used on equipment should conform to this.
Manufacturer’s specifications
Stages or bowls are added to a line shaft turbine pump to increase this.
The total head that pump produces
Operating a centrifugal pump near shut-off for an extended period of time can cause these problems.
- Pump damage due to overheated water, or impeller vibration
- Very poor efficiency
Operating a centrifugal pump near runout on the pump curve can cause these problems.
- Motor damage due to excessive amp draw
- Very poor pump efficiency
Slow opening valves on high pressure pumps are important to avoid this problem.
Water hammer when the pump starts
Pumping term for the vertical distance from the inlet water level to the discharge water level.
Total static head
Normal start amps for a pump motor.
3 to 5 times the normal running amps
Function of wearing rings on a centrifugal pump.
Prevents pump internal recirculation
The “C” factor for pipe indicates this.
The internal roughness of the pipe (The higher the “C” factor, the smoother the pipe)
Suction lift for a centrifugal pump, at sea level:
- Practical lift
- Theoretical lift
- Practical lift 15 to 20 ft
- Theoretical lift 33.9 ft