Water Distribution System: Key Requirements

Module 1 Review Questions

• Commercial demand includes water for manufacturing.
• Providing sufficient volume is the most challenging purpose of distribution system.
• Repair must be completed and pressure restored if distribution pressure drops below 20 psi during a main repair.
• A water distribution system must provide continuous delivery, potable/palatable water, sufficient volume, and adequate pressure.
• Potable water is free of pathogens and contains a chlorine residual.
• Water should have no disagreeable taste, odor, or appearance to be considered potable.
• Flush the mains to maintain palatable water.
• The TCEQ requires a minimum pressure of 35 psi under normal conditions.
• The TCEQ requires a minimum pressure of 20 psi under emergency conditions.
• Maintaining a minimum pressure helps to prevent backflow contamination.
• A water distribution system must meet domestic, commercial, industrial, and public demand.
• Water wells and treatment plants are not components of the water distribution system.

Module 2 Review Questions

• Mains are required to carry enough water at good pressure, provide continuous delivery and protect water quality.
• Water mains are required to be sized based upon present and future needs.
• A water system needs to be able to supply at least 500 gpm for 2 hours at peak demand to have minimum state recognition when firefighting.
• Using consumption records is the best way to estimate water demand.
• Plastic pipe must have a State Sanitation Foundation seal of approval.
• Do not use pipe previously used for food products in a public water supply.
• THe higher the Internal pipe wall, the smoother the wall.
• Scaling is an uneven mineral deposit but tuberculation uneven mineral deposit that forms barnacles or nodules
• The Bayliss Curve, Langelier Index, and Calcium Carbonate Saturation Test show scaling and corrosive tendancies
• Water mains purpose is to transport water through the system
• Main considerations for selecting water main pipe are diameter and material
• Main line pipe must have strength
• The lead ban prohibits use of more than 0.25% in pipes/fittings and solders/flux containing more than 0.2% lead
• Water hamer is due to a sudden change in water velocity or flow direction/the possible cause of the pipe damage
• Impact strength of PVC pipe is weakened by UV radiation and low temperature
• C-Factor Measures the smoothness of a pipe's interior
• Galvanic corrosion is caused by dissimilar metals in contact
• MJ and push-on joints are most commonly used in pipe connections.
• Cost of pipe is the price of the pipe, cost of installation, material life cycle, and maintenance cost.

Module 3 Review Questions

• Water lines go from the source to the customer's meter.
• The customer's meter area is not included in the service line assembly.
• The corporation stop is connected to the mains with a direct tap that uses a saddle.
• The meter stop or a curb stop connects the service line to the meter.
• A typical single-family residential is not 3/4-inch to 1-inch in diameter.
• Tubing, such as rubber or aluminium is not used in single-family service lines
• Copper isn't approved for service lines, but at large levels it requires the same action as with lead lines.
• The service line runs between the main and a user's meter.
• The service line assembly comprises of the main valve, piping, and the meter valve.
• Lead us no longer allowed for service lines because it is toxic.
• Large service lines usually use main line materials.
• Main taps are not made on the top of the pipe because air discharges into the service connection/tap fittings cannot be secured
• Flexible tubing have a goosesneck on end and bedded.

Module 4 Review Questions

• Valves are used to control water flow
• A valve's functional classification is used for isolation or control.
• Isolation valves are not used to throttle flow.
• The majority of distribution valves are not control valves.
• Gate valves are the most common main line isolation valve/
• Ball valves are the most common service line isolation valve.
• In terms of control, the valve manages pressure, volume, or flow direction.
• Slide, rotary, globe, and check valves are included in valve classification.
• Types of slides: gate, sluice gate and slice.
• Rising stem valves indicate open or closed position by the stem position.
• Rising stem valves are used in underground applications.
• Turns to open or close a threaded-stem doubled-disk gate valve are two times the valve size, plus or minus three.
• Butterfly, cone, and ball valves are rotary valves.
• Operated through a right-angle gear drive, A butterfly valve stem.
• Headloss is caused by a fully open butterfly valve because the disk remains in the flow.
• Noise or vibration can be caused by valve cavitation.
• Altitude valve controls water levels in tanks of different overflow elevations.
• All basic valve components include the body/framework, operator, moveable elements, and connections.
• Pathway is not a gate valve design.
• Larg-diameter, high-pressure valves is where butterfly valves are used
• Small service line valves are cone.
• Valves have a sphere that rotates through a valve body to allow, restrict, or stop flow.
• Gate valve is a household faucet
• Needle valve is a globe variation.
• Flexible material pressed on the valve seat by operation is used for Diaphragms
• Yearly basis main line valves should be operated
• Aboveground valves should be inspected, operated, and lubricated quarterly.
• To do valve maintenance: locate valve, write work orders, exercise valve, and record maintenance
• Velocity cavitation occurs when water velocity is higher than valve design.
• Less pressure and water vapor causes vapor bubbles to from destroying body/impeller.

Module 5 Review Questions

• Fire hydrants are meant to provide service by flushing and flow testing water, and provide municipal water
• Contractor water is not a fire hydrant's purpose
• The traffic safety model is a traffic model because it breaks if a vehicle hits
• Install hydrants so they are 9 feet away from sanitary waste lines vertically and horizontally
• Do not put a concrete block under the shoe of hydrants
• Install hydrants 2-6" under bottom of ground flange and ground level
• You don't have to fill drainage with crushed rock
• Street markers are used to help night locate hydrants.
• The AWWA uses blue for hydrants that yield less than 500 gpm.
• Fire Hydrants are to prevent water hammer from closing off too quickly.
• There is possible foreign matter if the hydrant is restricted before fully open
• Twice per year hydrant maintenance should be performed.
• Fire department contacted when fire hydrant out of or in operation.
• Parts of a Fire Hydrant: Operating nut (B), Weather shield (D), Bonnet (F), Hose nozzle (G), Upper barrel (H), Pumper nozzle (I), Ground flange (E), Lower barrel (C), and Shoe (A).
• Internal Parts of Fire Hydrant: Lubrication chamber (B), Operating stem (E), Main valve assembly (C), Seat ring (D), and Drain ring (A).

Module 6 Review Questions

• Production facilities fluctuate at a continuous rate because storage levels decrease at a uniformity.
• It ensures that water storage keeps the system prepared.
• Extra time is granted for disinfection with the use of water storage.
• A ground storage tank's height isn't the same as it's diemeter.
• The standpipe's height is larger than it's diameter is not always tru
• Located above 180" for service above tank at lowest elevated water
• The pneumatic system isn't counted as meeting requirements.
• All requirements for systems must be met at all times.
• Under 20 people is use to allow use
• Elevated storage capacity is not equal
• Elevated storage tanks provide pressure when pumps are turned off.
• Ground level means maintain is is easier
• Designed around TECQ for standard
• Corrosive resistant screens to be finer
• Access to thirty-inch diameter for openings in storage cannot be less than
• A tank without proper inspection is modified within
• Water storage has curbing locks and overlapping covers
• All locks should remain locked except if is used for maintenance and inspections
• Overflows will have soring, hinged, and weighted covers and the gap must be tight
• Discharge openings require maintenance at ground level
• Level liquid indicators are necessary within tank, wells, and systems.
• Drainages will connect with waste disposal
• Water tanks should follow standards for maintenance and care
• Lack of lead coating causes contamination
• Tank coating conform to ANSI
• Tanks are not required if water is undrinkable.
• Lockable to deter intruder.
• The wire fence must extend and have angle
• Ground maintenance for all tanks requires the same as at ground elevation
• System must inspect pressure and system tank
• Site maintenence of tanks requires maintenance of surroundings
• Metal breakdown results with corrosive and iron bacteria.
• Preventing contact with corrosion with all protection
• Chemically stable water is is neither
• Water to adjust to deposit
• Corrosive inhibitors are liquids, acids, or bases
• Water stability indicators need calcium saturation test and langeiler
• Metal covers need b and c for support Non-metallic coverings need mortar to endure.
• Cathodic protection refers to corrosion electrochemical prevention.
• Operators must use vents so they are not open or blocked during cleaning.
• The interior is the clear and safe storage
• Gases, and oxygen
• Workers and staff will monitor the entrance
• Methods for required in chlorine residue of water, requires a tank free.
• A chlorine solution at minimum must be retained before a dosage is added.
• Corrosion is caused by
• Water to adjust to deposit
• Corrosive inhibitors are fluids, acids, or bases
• Water stability indicators can be altered to a safe state
• Metal coverings need mortar to endure.
• During
• With minimum solution

Module 7 Review Questions

• The pressure in psi is equal to .433 times the feet of head. False
• Closing a valve too slowly is a common cause of water hammer. False
• When water is not moving, it is under dynamic conditions, and, when it is moving, it is under state conditions. False
• Water velocity is measured in feet per second. True
• The cross-sectional area of the pipe or channel is at right angles to the direction of flow, measured in cubic feet. False
• By increasing the diameter of a waterline, friction loss can be reduced. True
• If the hydraulic grade line drops to a level where a partial vacuum occurs, a waterline may experience backflow. True
• Pumps provide the velocity head for the movement of water from one point to the distribution system to another. False
• The vertical distance in feet between the pump's centerline and the top of the water level on the pump's discharge, or point of free discharge, is “discharge head.” True
• “Friction head” is the head caused by friction losses in the pipe and fittings. True
• Wear rings are a replaceable bearing surface between the impeller and casing. True
• A centrifugal pump impeller throws the water by centrifugal force into a progressively contracting spiral casing. True
• Lubricants that contact potable water must be food-grade. True
• Always tighten packing to the point of no leakage. False
• Mechanical seals eliminate almost all leakage and have a longer service life. True
• Greater installation will produce greater pressure
• One example of a pump connection is a well pump.
• By too much NPHS, Cavitation is caused.
• A pump provides the changes in
• Closed is the best solution, not against. Power sources for motors include the given circuits. Electric charge in the rotor is from being in the stated. Brake horsepower from output from it. A typical four-cycle motor is indicated. High levels take shorter levels Continuous duty over long periods. The motor has a high rating. Diagram has proper connections Angle under 15 degrees A motor casing uses air Includes Careful check of rotors.

Explore the essential requirements of a water distribution system, focusing on continuous delivery, potable water, sufficient volume, and adequate pressure. Understand TCEQ's minimum pressure standards and the importance of preventing backflow contamination. Learn about meeting diverse demands and maintaining water quality through flushing.