What is the general definition of an ion? An _________ with a positive or negative charge
Atom
A continuous positive pressure in a distribution
... [Show More] system is essential for preventing what event?
Backflow Event
_____________ water pressure must be maintained to ensure adequate customer service during peak flow periods. However, minimum positive pressure must be maintained in mains to protect against backflow or backsiphonage from cross-connections.
Minimum
Name the most common CAUSE for public water supply contamination. _________________ or cross-connection
Backflow
What does a backsiphonage condition usually cause? __________ pressure or negative pressure on the service or supply side.
Reduced
What does a double check valve backflow assembly provide effective protection from? Both backpressure and backsiphonage of ____________.
Pollution
What is equipment that utilizes water for cooling, lubrication, washing or as a solvent always susceptible to?
Cross-Connection
What is the difference between a reduced pressure principle backflow device and a double check backflow device? The RP has a ______________.
Relief Valve
What is the maximum time period between having a backflow device tested by a certified backflow tester? ______________ year.
1
What is the regulatory definition of a cross-connection in a water supply? A physical connection between a public water system and any source of water or other substance that may lead to contamination of the water provided by the _____________ through backflow.
PWS
What is the name of a type of valve that reduces the differential pressure across a closed disk making the main valve easier to open and close?
Bypass Valve
As soon as Cl2 gas enters the throat area, a victim will sense a sudden stricture in this area-Nature's way of signaling to prevent passage of the gas to the lungs. At this point, the victim must attempt to do two things: get out of the area of the leak, proceeding upwind, and to take only very short breaths through the mouth. Normal breathing will cause __________, which must be prevented if possible.
Coughing
Chlorine gas causes suffocation, constriction of the chest, tightness in the throat, and edema of the ______________.
Lungs
_______________ available chlorine is very effective in killing bacteria.
Free
How should an operator store an empty chlorine cylinder? ____________, tagged as empty.
Upright
If a chlorine leak occurs, where will chlorine gas accumulate? Near the ____________ of the tank.
Bottom
What effect does chlorine gas have on the sense of smell? It produces olfactory _______________.
Fatigue
What is the primary safety concern when using chlorine gas as opposed to calcium hypochlorite or sodium hypochlorite? The potential for a _____________ leak.
Gas
What may occur due to chronic exposure to low concentrations of chlorine gas? Chronic exposure may cause corrosion of the _____________.
Teeth
What is the process called that changes water vapor to tiny droplets or ice crystals?
Condensation
What is the unit of measurement for sound?
Decibels
What happens if grease comes in contact with the winding of a motor?
The winding insulation my deteriorate.
What is the most common type of valve used in isolating a small or medium sized section of a distribution system?
Gate
What is a possible result of over greasing a bearing? There is extreme _____________ in the bearing chamber causing heat and scoring of the shaft.
Friction
What is meant by the term "peak demand?" The _____________ momentary load placed on a water treatment plant, pumping station or distribution system.
Maximum
What is the range of the pH scale? between _____________-14.
Zero
What does a Bellows-type sensor reacts to a change in? _________________.
Pressure
Centrifugal pumps do not generate suction unless the impeller is submerged in water. If a pump is located above the level of water what must be provided on the suction piping to hold the prime?
Foot Valve
What causes pump cavitation? A suction line may be ____________ or the pump is above the waterline. You have overpumped the well.
Clogged
What does continuous leakage from a mechanical seal on a pump indicate? The mechanical seal needs to be ___________________.
Replaced
What is a possible cause of a scored shaft sleeve? The _____________ has broken down
Packing
What is one disadvantage of a centrifugal pump? It is not______________.
Self-Priming
What is the best seal to use for a pump operating under high suction head conditions? A _____________ seal.
Mechanical
What is the common method used to secure an impeller to the shaft on double-suction pump? A _____________ and a tight fit.
Key
What is the main purpose of the wear rings in a centrifugal double suction pump? The wear rings maintain a flow _______________ between the impeller discharge and suction areas.
Restriction [Show Less]