Wastewater Collections (Class Ii)

WASTEWATER COLLECTIONS (Class II) The amount of oxygen that may become dissolved in a given amount of water is MOST related to... - ANS Temperature The gas most commonly associated with septic wastewater is... - ANS Hydrogen sulfide What determines the amount of hydrogen sulfide produced in a sewer? - ANS pH Four conditions are necessary to create an explosion. Three of these conditions are: combustible gas, adequate oxygen, and sufficient heat. What is the fourth condition? - ANS Proper mixing of gas and oxygen One kilowatt is the equivalent of _____________ horsepower. - ANS 1.34 The lack of an unpleasant odor in a manhole, lift station, or other structures does NOT always mean that no dangerous gasses are present because... - ANS -Most dangerous gases have no odor -Oxygen may still be lacking -Some gasses deaden the sense of smell As the impeller wears on a pump, the pump efficiency will... - ANS Decrease How closely an instrument measures the actual value of the process variable being measured is called its... - ANS Accuracy Vibrations in pumps may be caused by improper motor-pump... - ANS Alignment Advantages of a video tape recording system include... - ANS Length and severity of defective areas can be recorded The MOST widely used type of prime mover in a pumping plant is... - ANS Electric motor "Schedule 40" refers to... - ANS Wall thickness Hazards that may damage a TV camera going through a sewer include... - ANS - Deep water that submerges the camera - Fogging of optical lens - Offset joints Centrifugal pump parts include... Diaphragm? Piston? Rotor? Volute? - ANS Volute When packing a centrifugal pump, how should the packing gland be tightened? - ANS Slowly, over a period of several hours