1
Q
What are the two types of water distribution systems in a building?
A
- Upfeed piping system
- Downfeed piping system
These systems determine how water is distributed throughout a building.
2
Q
Name the three common upfeed water systems.
A
- Direct pressure system
- Tankless constant pressure system
- Pressure system
These systems are used to manage water distribution in buildings.
3
Q
In a direct pressure system, where does the water come from?
A
Municipal distribution system or private supply
Water enters the building at approximately 420 kPa (60 psi).
4
Q
What is the role of the meter in a direct pressure system?
A
Measures water flow in the basement
It helps in monitoring the water supply entering the building.
5
Q
In a tankless constant pressure system, what is the purpose of the booster pump?
A
Increases system water pressure
It compensates for pressure loss as water moves vertically up the risers.
6
Q
How much pressure does water lose for every metre of elevation in a tankless constant pressure system?
A
Approximately 10 kPa (1/2 psi)
This loss necessitates the use of booster pumps.
7
Q
What is the function of a pressure reducing valve (PRV) in a tankless constant pressure system?
A
Reduces water pressure to an acceptable level
PRVs are installed on each floor to manage water pressure.
8
Q
Where is water for the building fire system taken from?
A
Directly off the city water supply before the water meter
This ensures that the fire system has a reliable water source.
9
Q
What is the purpose of a backflow preventer in the fire system piping?
A
Prevents backflow into the city water supply
It is a safety measure to protect the public water supply.
10
Q
What happens when the water pressure drops due to increased demand in a tankless constant pressure system?
A
A pressure switch energizes the second pump
This ensures adequate water pressure is maintained.
11
Q
What is the design of dual alternating/intermittently running pumps in a tankless constant pressure system?(2)
A
- One pump in continuous service
- Second pump on standby
This design allows for efficient management of water pressure.
12
Q
What is the purpose of a pneumatic tank in a water supply system?
A
To maintain pressure and supply water from the tank
The tank pressure forces the water from the tank, boosting the pressure for distribution.
13
Q
What are the two types of hot water supply systems in buildings?
A
- Domestic hot water distribution system
- Domestic hot water recirculating system
These systems are designed to convey hot water to plumbing fixtures.
14
Q
What is a disadvantage of the domestic hot water distribution system?
A
Temperature drop and water waste when fixtures are not used
Hot water stagnation occurs, requiring a large amount of water to be wasted before hot water is available.
15
Q
How does a domestic hot water recirculating system work?
A
It has a return line connected to the water heater
This design eliminates stagnation and allows hot water to be available sooner.
16
Q
What principle induces circulation in a hot water recirculating system?
A
Natural circulation due to water expansion and decreased density when heated
This is also known as convection.
17
Q
What is the function of a downfeed system in water distribution?
A
To provide storage capacity and maintain pressure for cold water
A storage tank is placed above the highest fixture in the building.
18
Q
What is the maximum pressure allowed on lower floors in a downfeed system?
A
550 kPa (80 psi)
Pressure reducing valves are used to manage excess pressure.
19
Q
What type of tank is used in high buildings for water distribution?
A
Multiple gravity feed tanks
These tanks are located at different intermediate levels to maintain pressure.
20
Q
What is the role of a multi pump system in water distribution?
A
To maintain the proper level of water in the house tank
This system is connected directly to the municipal supply.
21
Q
What is a pressure system with a pneumatic tank used for?
A
When building water demand intermittently exceeds supply or when source pressure is insufficient
This system boosts pressure and maintains a minimum required system pressure.
22
Q
What does the pressure regulating valve do in a pneumatic tank system?
A
Maintains a minimum required system pressure in the tank
It also helps in stopping the pump at a maximum level set point.
23
Q
What is the function of float control systems in water tanks?
A
Controls the level in the suction and house tank
Float switches are often used to start and stop pumps.
24
Q
How does a domestic hot water recirculating system improve efficiency?
A
Eliminates hot water stagnation and provides hot water sooner with less waste
It has a return line connected to the water heater.
25
What induces natural circulation in a **hot water recirculating system**?
Water expands and becomes less dense when heated
## Footnote
This process is also known as convection.
26
What is the principle of **natural hot water recirculation** based on?
Gravity
## Footnote
Heavier cold water displaces lighter hot water, creating circulation.
27
What must be installed in the return line of a hot water system to prevent backflow?
Check or backflow valve
## Footnote
This prevents colder water from entering hot water lines.
28
In a hot water system, what is the role of a **pump**?
Keeps water circulating
## Footnote
A pump maintains flow through the system and back to the heater.
29
What is the typical pressure maintained at the **top floor** of a building's water system?
175 kPa (25 psi)
## Footnote
This pressure is necessary for adequate water supply at higher elevations.
30
Fill in the blank: A **hot water recirculating pump** is used to maintain a constant hot water temperature at each _______.
floor
## Footnote
This ensures consistent hot water availability throughout the building.
31
What happens if the **supply pressure** for hot and cold water increases again to 539 kPa (78 psi)?
Pressure reducing valves may be used
## Footnote
These valves help manage excessive pressure on lower floors.
32
What is the role of **automatic air vents** in a hot water system?
Remove air from hot water risers
## Footnote
They help maintain efficient water flow by eliminating trapped air.
33
What are the two classifications of **hot water heaters** in commercial buildings?
* Direct heaters
* Indirect heaters
## Footnote
Direct heaters heat water by burning fuel or using an electric element, while indirect heaters use heat energy from steam or hot water.
34
In a **direct hot water heater**, what is the primary function of the single tank?
Heating and storing water
## Footnote
A common type is an automatic gas-fired storage heater.
35
What is a common feature of a **gas-fired storage heater**?
Gas burner located beneath a central flue
## Footnote
This design increases heat transfer efficiency.
36
What type of hot water heater is being used to replace older inefficient designs?
Compact and modern wall-hung instantaneous water heaters
## Footnote
These heaters have modulating gas valves to vary the amount of gas used.
37
What temperature does water flow from the storage tank directly to the kitchen and laundry in the hot water system?
Approximately 80°C (176°F)
## Footnote
This high temperature is required for sterilization.
38
What is the purpose of the **three-way mixing valve** in the hot water system?
To blend hot water at 80°C with cooler water
## Footnote
This maintains water temperature between 50°C (122°F) and 60°C (140°F) for other fixtures.
39
What device regulates the ratio of flows at the mixing valve in the hot water system?
Aquastat
## Footnote
It maintains the proper hot water temperature.
40
What type of water heater is known as an **instantaneous or tankless water heater**?
A type that heats water instantaneously as it flows through the tubes
## Footnote
It does not require a storage tank.
41
What is used to control the burner output in an instantaneous water heater?
A thermostat
## Footnote
This helps maintain a safe hot water temperature at plumbing fixtures.
42
Fill in the blank: **Instantaneous water heaters** require a _______ to temper the hot water leaving the heater.
thermostatically controlled mixing valve
## Footnote
This prevents accidental scalding by mixing cold water with hot water.
43
What are the two types of **direct hot water heaters**?
* Storage type
* Instantaneous type
## Footnote
Direct hot water heaters are heated by steam or high temperature water from a heating system.
44
How is the flow of steam regulated in **direct hot water heaters**?
By a **thermostatically controlled valve**
## Footnote
This valve increases the steam flow when the water temperature drops below a set value.
45
What is the purpose of a **thermostatic mixing valve** in hot water systems?
Required on the hot water supply leaving the heater
## Footnote
It ensures safe water temperatures at the outlets.
46
What does a **steam trap** do in a hot water heating system?
Removes condensate from the heater and returns it to the condensate return
## Footnote
This is crucial for maintaining system efficiency.
47
What temperature range is typically maintained for **hot water outlets** in buildings?
50°C to 60°C (122°F to 140°F)
## Footnote
This range is important for safety and comfort.
48
What is the function of a **circulation pump** in an indirect hot water system?
Maintains a positive flow in the proper direction
## Footnote
It is installed between the heater and the storage tank.
49
What type of heat exchanger is now commonly used in newer installations for hot water systems?
Stainless steel plate heat exchangers
## Footnote
They are more efficient and require less maintenance than traditional tube and shell heat exchangers.
50
What is the role of a **temperature control valve** in an indirect hot water system?
Controls the flow of steam or hot water to the heat exchanger
## Footnote
This ensures the water is heated to the desired temperature.
51
In an **instantaneous indirect heater**, how is water heated?
By steam flowing through tubes surrounded by water
## Footnote
The steam flow is controlled by a thermostatically controlled regulating valve.
52
What is the function of a **self-operating temperature regulator** in a water heater?
It maintains a constant temperature by adjusting the valve based on the pressure of a volatile fluid in a bulb
## Footnote
The regulator consists of a bulb, tube, and valve actuating bellows.
53
Where can the **bulb** of a self-operating temperature regulator be installed?(2)
* Directly in the hot water tank
* Into a thermowell screwed into a heater
## Footnote
This allows for accurate temperature sensing.
54
What is required for efficient operation of a **water heater**?
The system must be maintained in good working order
## Footnote
Regular maintenance ensures optimal performance.
55
How does the **bulb** in a temperature regulator sense changes in hot water temperatures?
The pressure of the volatile fluid in the bulb varies with temperature changes
## Footnote
This pressure change causes the bellows to expand or contract.
56
What happens to the valve plug when the **hot water temperature** is at the desired maximum?
The valve plug is closed so no steam flows into the heating coil
## Footnote
This prevents overheating and maintains the set temperature.
57
What occurs when the **hot water temperature** decreases?
The pressure of the volatile fluid decreases, allowing more steam or hot water to flow into the heater
## Footnote
This action helps to restore the desired temperature.
58
What is the role of the **valve spring** in a temperature regulator?
It compresses the bellows to adjust the valve position based on temperature changes
## Footnote
The spring helps maintain a balance between hot water demand and supply.
59
At **peak demand** for hot water, what is the position of the valve?
The valve will be almost fully open
## Footnote
This allows maximum steam flow to meet high hot water needs.
60
What is **backflow**?
The reverse direction of the normal flow of water or other liquid into the distributing pipes of a potable water supply
## Footnote
Backflow can be caused by back siphoning or back pressure.
61
What are the two causes of **backflow**?
* Back siphoning
* Back pressure
## Footnote
Back siphoning occurs due to negative or sub-atmospheric pressure, while back pressure is caused by downstream pressure.
62
Define **cross connection**.
Any connection between the potable water supply and other sources that may introduce contaminants
## Footnote
Cross connections can lead to backflow into the potable water system.
63
What must be considered before choosing a **backflow preventer**?
The degree of hazard
## Footnote
The type of device used is determined by whether there is back pressure and/or back siphoning.
64
What is an **air gap** in backflow prevention?
A physical separation between the free flowing discharge end of a potable water pipe and a plumbing fixture
## Footnote
It prevents unsanitary water from being siphoned back into potable water.
65
What is the function of a **vacuum breaker**?
To allow entry of air if there is a partial vacuum in the water pipe, eliminating siphoning
## Footnote
It is placed immediately below the flush valve to prevent waste from flowing back.
66
What does the **Reduced Pressure Principal Device (RP)** consist of?(2)
* Two independently acting check valves
* An automatic operating pressure differential relief valve
## Footnote
It maintains lower pressure between the check valves than the supply pressure.
67
What is a **Double Check Valve Assembly (DCVA)**?
A device consisting of two independently acting check valves that close in a pressure differential
## Footnote
It is commonly found on fire systems or underground irrigation water services.
68
What is the purpose of a **Pressure Vacuum Breaker (PVB)**?
To admit air whenever the pressure within the body approaches atmospheric pressure
## Footnote
It consists of a spring-loaded check valve and is found on steam sterilizers.
69
What does an **Atmospheric Vacuum Breaker** do?
Prevents water from spilling and breaks the siphon effect by allowing air in when water pressure is lost
## Footnote
It is located on exterior hose bibs.
70
What is the purpose of **safety devices** in water systems?(2)
* Prevent dangerously high pressure
* Prevent dangerously high temperatures
## Footnote
Safety devices are essential to protect the system from potential hazards due to pressure and temperature fluctuations.
71
What happens to water in a system when it is heated?(2)
* Expands
* Increases pressure
## Footnote
If the hot water cannot expand back into the cold water supply pipe, it can lead to dangerously high pressure.
72
What can prevent dangerously high pressure in a water system?(2)
* Pressure relief valve
* Pressure reducing valve
## Footnote
These devices help manage pressure build-up in the system.
73
At what temperature does water boil at atmospheric pressure?
100°C (212ºF)
## Footnote
Heating water above this temperature in a pressurized system can lead to superheating.
74
What is a potential danger of superheated water?(2)
* Sudden expansion
* Flashing into steam
## Footnote
This can cause scalding when discharged from faucets.
75
What should be avoided in the discharge piping from a pressure relief valve?
* Direct connection to any drain or vent
## Footnote
Discharge should be piped to a safe disposal point above a floor drain.
76
What are common causes for frequent opening of a pressure relief valve?(3)
* Scale accumulation on the valve seat
* Variations in supply line pressure
* Defective valve
## Footnote
Identifying and remedying these causes is crucial for system safety.
77
What does a **temperature relief device** do?
Opens when water temperature reaches approximately 99°C (210°F)
## Footnote
This allows hot water to escape and cold water to enter, reducing temperature.
78
What is a **fusible plug**?
A material that melts at 99°C (210°F) to allow hot water to escape
## Footnote
It is used in some temperature relief devices but may be unsatisfactory if water continues to leak until replaced.
79
What happens when the **maximum safe level** of pressure is reached?
The valve plug will be forced off its seat
## Footnote
This is a safety mechanism to prevent overpressure in the system.
80
At what temperature does the **wax-filled sensor probe** expand to operate the valve?
99°C (210°F)
## Footnote
The expansion of the wax-filled sensor is crucial for the valve operation.
81
What should be done periodically to prevent **scale deposits** in the valve?
Open the manual relief lever
## Footnote
This helps break loose any scale deposits before they build up.
82
Where should the **temperature relief valve** and combination pressure-temperature relief device be located?
Within the top 15 cm (6 in) of the storage tank
## Footnote
This location ensures effective maintenance of water temperature.
83
What is the purpose of the **High Limit Energy Cut-Off**?
To cut off the heating medium to the water heater when maximum temperature is reached
## Footnote
This prevents overheating and potential hazards.
84
What is the function of **water hammer arrestors**?
To eliminate noises in the piping system caused by water hammer
## Footnote
They help prevent damage to the system by absorbing shock.
85
What is the primary function of **water** in drainage systems?
To help move soil and waste material in the drainage piping
## Footnote
Water facilitates the flow of sewage through the drainage system.
86
How do drainage systems typically flow?
By gravity to the municipal sanitary sewer or a sump
## Footnote
Pumps are used when sewage must be lifted from a sump to a higher elevation.
87
What do the terms **soil** and **waste** refer to in sewage systems?
The type of material conveyed in a sewage pipe
## Footnote
Wastes from plumbing fixtures are categorized as soil or waste.
88
What is the role of a **P-trap** in drainage systems?
To discharge wastes from plumbing fixtures into the drainage system
## Footnote
Wastes pass from the fixture outlet pipe into the P-trap.
89
What becomes the **sanitary building drain** in a drainage system?
The base of the vertical stack
## Footnote
The vertical stack collects waste from horizontal branches.
90
What is the purpose of **branch lines** in a building's drainage system?
To collect and remove soil or waste from different types of plumbing fixtures
## Footnote
Branch lines are provided on each floor of a building.
91
What is the function of **horizontal branch piping**?
To convey wastes from fixtures to a waste or soil stack
## Footnote
This piping must be designed to maintain proper flow.
92
What is the purpose of a **trap** in plumbing fixtures?
To provide a water seal that prevents sewer gases from entering the building
## Footnote
Traps are integral in water closets and some urinals, while they are installed externally in other fixtures like sinks.
93
What is the typical **depth** range of traps in plumbing?
* 3.8 cm (1-½ in)
* 10 cm (4 in)
## Footnote
Increasing the depth of traps assures greater resistance to evaporation.
94
What should be done periodically to maintain a **water seal** in traps?
Water must be added periodically
## Footnote
If plumbing fixtures and floor drains are rarely used, the water in the trap will evaporate, allowing sewer gases to enter the building.
95
What is a **grease trap** or interceptor used for?
To remove grease, oil, or cooking fats from waste before they clog drainage lines
## Footnote
This is accomplished by passing the liquid into a grease trap or interceptor.
96
What happens to the **oil and grease mixture** in a grease trap?
It rises to the surface and collects in the grease retention area
## Footnote
The water and grease mixture is deflected upward by the integral ramp.
97
What is the main function of **venting** in a plumbing system?
To maintain atmospheric pressure in the piping drainage system
## Footnote
Venting prevents positive pressure from forcing sewer gases back through traps and negative pressure from drawing sealing liquid out of traps.
98
Why is it important to displace air in the **drainage system** when wastes are discharged?
To prevent sewer gases from entering the building
## Footnote
Proper venting design and distance from fixtures to the vent are crucial.
99
What is the purpose of a **sump** in a building?
To collect and lift liquid sewage to a higher elevation for pumping into the sanitary building drain
## Footnote
A sump is necessary when the lowest drain is below the level of the municipal sewer line.
100
What materials are commonly used for **indoor sanitary drainage piping**?(6)
* PVC
* Cast iron soil pipe
* Galvanized steel pipe
* Copper tube
* Corrosive resistant PVC
* Boro-silica glass
## Footnote
These materials may vary based on the specific requirements of the drainage system.
101
What is the function of a **vent stack** in a multi-storey building?
To equalize atmospheric pressures and vent plumbing fixtures discharging into a horizontal branch
## Footnote
The vent stack is connected to the bottom of the soil stack to limit pressure differentials.
102
What is the purpose of **cleanouts** in drainage lines?
To allow access for cleaning and inspection service
## Footnote
Cleanouts are typically found at the base of plumbing stacks and above running traps.
103
What happens to ice accumulation in the **stack vent** during cold climates?
It can affect the drainage system and prevent the movement of atmospheric air
## Footnote
Ice build-up should be checked during cold weather.
104
What type of fittings should be used for connections to the **stack**?(3)
* TY fittings
* Y fittings
* 45 degree elbows
## Footnote
These fittings help maintain proper drainage and venting.
105
What is the role of the **venting system** in plumbing?
To provide a continuous supply of air to horizontal branch lines and prevent siphoning of traps
## Footnote
This ensures proper drainage and function of plumbing fixtures.
106
What is the main function of a **storm water drainage system**?
To remove storm water and provide sub-surface drainage into a storm sewer
## Footnote
Most jurisdictions require separate storm and sanitary sewage systems in a building.
107
What are **gutters** used for in storm water drainage?
To convey rainwater from a roof to a vertical pipe called a leader or downspout
## Footnote
Gutters may be constructed as an integral part of the roof or as a separate attachment.
108
In a storm drainage system, what is the purpose of a **vertical leader**?
To collect rainwater from the roof and direct it to a storm drain
## Footnote
The roof drainage system is divided into sections, each with a vertical leader.
109
What is required for all **sewage sumps** according to plumbing regulations?
A plumbing vent leading to the roof of the building
## Footnote
This ensures proper ventilation and prevents obstruction in the venting system.
110
What type of pumps are often used for raising sewage to a higher level?(2)
* Submersible-type centrifugal pumps
* Air-operated sewage ejectors
## Footnote
These pumps are used to ensure proper drainage and maintenance.
111
What is the purpose of a **high water alarm** in sewage systems?
To indicate trouble in the sump when the sewage level is too high
## Footnote
It may be a visual light or an additional float switch.
112
The diameter of the **vertical leader** depends on what factor?
The roof area that it serves
## Footnote
The size of the story drain is increased gradually as additional leaders are added.
113
What angle do all leader drains meet the **storm drain**?
45 degrees
## Footnote
This angle is important for proper drainage functionality.
114
What materials are commonly used for **storm piping** located inside a building?(4)
* Cast iron
* Galvanized steel
* Copper
* PVC
## Footnote
These materials are chosen based on durability and local regulations.
115
What is the purpose of **cleanouts** in storm drainage systems?
To allow for the clearing of blockage
## Footnote
Cleanouts are provided near the base of a vertical leader and at intermediate points on a horizontal line.
116
What is the function of **weeping tile** in subsoil drainage?
To prevent accumulation of ground water around building foundations
## Footnote
It helps reduce hydrostatic water pressure on walls below ground level.
117
What should be done at least once a month to a **storage heater**?
Open the drain valve to remove sediment
## Footnote
This prevents sediment from building up in the bottom of the heater.
118
What are the two types of relief protection required for hot water storage tanks?
* Temperature relief valve
* Pressure relief valve
## Footnote
These valves ensure safe operation by preventing excessive temperature and pressure.
119
What is the maximum temperature a **temperature relief valve** is designed to prevent?
99°C (210°F)
## Footnote
This is crucial for maintaining safe water temperatures in storage tanks.
120
What happens if **condensate** is not promptly removed from a heating element?
Water hammer could occur
## Footnote
This can potentially damage the heater tubes.
121
Fill in the blank: **Piping expansion** and contraction above grade is very important due to _______.
temperature variations
## Footnote
Temperature changes can cause stress at joints and connections.
122
What is the purpose of **water faucets**?
Control the flow of water
## Footnote
Faucets are used at discharge fixtures such as sinks, lavatories, and tubs.
123
What are the two main types of **valves** mentioned?
* Globe valves
* Compression style valves
## Footnote
Valves are used to close off portions of the plumbing system.
124
What is a common cause of **faucet leaks**?
Failure to turn the faucet completely off
## Footnote
This wears out the rubber washer inside the faucet.
125
What should you do first to replace a **faucet bibb washer**?
Shut off the supply of water at the nearest isolation valve
## Footnote
This is crucial to prevent water flow during the repair.
126
What indicates that a **compression style faucet** seat may be rough?
If the faucet leaks for an extended period of time
## Footnote
This may require a seat removal tool for repair.
127
What material can be used as **packing** if specific valve packing cannot be obtained?
Cotton or similar material saturated with graphite
## Footnote
This can be wrapped tightly around the stem after removing the packing nut.
128
What is a **washerless faucet**?
A faucet that uses rubber cup washers and springs
## Footnote
These faucets are easier to replace than older compression style faucets.
129
Fill in the blank: **Aerators** are located on the end of the _______.
spout
## Footnote
Keeping aerators clean is important for proper faucet function.
130
What should you do when replacing **O-rings** and washers?
Replace only with the size and type recommended by the manufacturer
## Footnote
Using the correct parts ensures proper function and prevents leaks.
131
What is the purpose of a **radiator valve**?(5)
To control:
* Steam entering the radiator
* Condensate leaving the radiator
* Steam leaving the radiator
* Air leaving the radiator
* Air entering the radiator
## Footnote
Radiator valves are essential for managing the flow of steam and air in heating systems.
132
What two valves operate a **water closet flush tank**?
* Float-controlled valve (ball cock or float valve)
* Discharge valve (flush valve)
## Footnote
These valves work together to manage water flow for flushing.
133
What happens when the **float rises** in a water closet flush tank?
The float-controlled valve shuts off
## Footnote
This mechanism prevents overflow and maintains the correct water level.
134
List reasons why a **ball cock** may not close properly.(5)
* Float arm incorrectly bent
* Float has a small leak
* Float rod requires adjustment
* Valve washer may require replacement
* Foreign material may hold the valve open
## Footnote
These issues can lead to persistent leaks and water level problems.
135
How can the operation of a **ball cock** be checked?
By raising the float arm
## Footnote
If water escapes, the ball cock is leaking, often due to a bad washer.
136
What should be done if a **flush valve** leaks?(5)
* Replace the ball if defective
* Clean the ball and seat
* Adjust the lift chain
* Ensure the flush ball seats properly
* Replace the flush seat if corroded or worn
## Footnote
Regular maintenance is crucial for proper function.
137
What are the two basic styles of **flush valves**?
* Diaphragm
* Piston
## Footnote
The diaphragm type is the most popular due to advancements in materials.
138
What is the typical volume of water discharged by a **flush valve** in ten seconds?
Approximately 13.7 L (3.62 US gallons)
## Footnote
This volume is essential for effectively flushing fixtures.
139
What can be done to prevent **condensation** on a water closet tank?(3)
* Attach a tray under the tank
* Use an inner Styrofoam liner
* Install a mixing or water tempering valve
## Footnote
These solutions help manage temperature differences that cause condensation.
140
What does the **diaphragm** in a flush valve do?
Divides the valve into upper and lower chambers
## Footnote
The diaphragm ensures equal water pressures in both chambers.
141
In the **flush operation**, what happens when the handle is moved?
Pressure is applied to both sides of the diaphragm
## Footnote
This pressure allows the plunger to contact the relief valve stem.
142
What occurs in the **flush valve** when the operating unit is fully raised?
Allows maximum flow of water to the fixture
## Footnote
The relief valve is closed at this point.
143
What happens during the **closing operation** of the valve?
Pressure in the upper chamber increases, forcing the operating unit downward
## Footnote
This occurs after the relief valve has closed.
144
What is the purpose of the **relief valve** in a flush valve?
Allows the stem to telescope within the relief valve unit
## Footnote
This design enables the valve to close even if the handle is held in the operating position.
145
How can the **length of the flush** be adjusted in a popular design of flush valve?
By turning a stem screw under a protective cap
## Footnote
Turning counter-clockwise lengthens the flush, while clockwise reduces it.
146
What is a **flexible auger** used for in plumbing?
To clean traps by inserting it into the fixture and turning the handle
## Footnote
The auger bites into an obstruction and is then withdrawn.
147
What causes **faucet noises**?(3)
* Worn washer
* Defective internal assembly
* Poor design
## Footnote
These issues can lead to leaks, drips, chattering, or whistling sounds.
148
What is **water hammer**?
A pounding or banging noise in pipes caused by a shock wave when water flow is suddenly stopped
## Footnote
It can cause serious damage to a plumbing system if not addressed.
149
What can be installed to absorb excessive pressure caused by water hammer?(3)
* Air chambers
* Diaphragm tank
* Water hammer arrestor
## Footnote
These devices help cushion the shock wave in the plumbing system.
150
What temperature should water not exceed for general use in a **water heater tank**?
55°C (130°F)
## Footnote
Exceeding this temperature can cause popping noises due to overheating.
151
What should be done if **chemical solutions** are used to clear stoppages?(2)
* Follow specific instructions on the container
* Allow water to flow through the drain for a considerable length of time
## Footnote
This ensures any remaining traces of the chemical are flushed out.
152
What can cause **water heater tank noises**?(2)
* Water too hot
* Heavily limed and scaled tank
## Footnote
These conditions can lead to popping noises during operation.
Power Engineering Book 2 Part 1
flashcards
Decks in class (3)
# Cards
