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ASSE 5110 practice questions

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Question 1Principles of backflow and cross-connection hydraulics

Water flowing through a potable water piping system in the direction opposite to the intended direction of flow is called:

  1. Spillage
  2. Backflow Correct answer.
  3. Backpressure
  4. Recirculation

Explanation

Backflow is the general term for any reversal of the intended direction of flow in a piping system, and it can be produced by either backsiphonage or backpressure. The specific mechanism that causes the reversal is named separately from the reversal itself.

Question 2Principles of backflow and cross-connection hydraulics

Any actual or potential connection between a potable water system and a source of contamination or pollution is known as a:

  1. Vacuum breaker
  2. Cross-connection Correct answer.
  3. Siphon break
  4. Backflow condition

Explanation

A cross-connection is the physical or potential link that makes contamination possible in the first place. Eliminating or protecting the cross-connection is the fundamental objective of a cross-connection control program.

Question 3Principles of backflow and cross-connection hydraulics

Backsiphonage occurs when:

  1. Pressure in the supply main drops below atmospheric, creating a partial vacuum Correct answer.
  2. Thermal expansion pushes heated water back toward the cold water main
  3. Elevated downstream piping develops a static head greater than the supply pressure
  4. A booster pump raises downstream pressure above the supply pressure

Explanation

Backsiphonage is driven by a pressure in the supply piping that falls below atmospheric, so atmospheric pressure pushes a nonpotable liquid into the system through an unprotected connection. The sub-atmospheric condition is usually created by a main break, a high fire-flow demand, or a pump drawing on the main.

Question 4Principles of backflow and cross-connection hydraulics

Backpressure backflow is best described as reverse flow caused by:

  1. A submerged inlet drawing pond water into a line under negative pressure
  2. Pressure on the downstream side that exceeds the pressure in the potable supply Correct answer.
  3. A partial vacuum forming in the supply main during a main break
  4. Capillary action lifting liquid through a small-diameter tube

Explanation

Backpressure exists whenever the pressure downstream of a connection is higher than the supply pressure, so the higher downstream pressure pushes nonpotable water into the potable system. Pumps, boilers, elevated tanks, and thermal expansion are common sources of that higher downstream pressure.

Question 5Principles of backflow and cross-connection hydraulics

Which method of protection provides complete protection against both backsiphonage and backpressure because it establishes a physical separation?

  1. A double check valve assembly
  2. A barometric loop
  3. An air gap Correct answer.
  4. A pressure vacuum breaker assembly

Explanation

An air gap is a physical, unobstructed separation between the potable supply outlet and the flood level rim of the receiving vessel, so neither backsiphonage nor backpressure can bridge it. It is the only method recognized as providing complete protection against both conditions.

Question 6Principles of backflow and cross-connection hydraulics

One foot of vertical elevation in a column of water produces a static pressure of approximately:

  1. 14.7 psi
  2. 8.33 psi
  3. 0.433 psi Correct answer.
  4. 2.31 psi

Explanation

A column of water one foot high exerts about 0.433 psi at its base, which is the same relationship as 2.31 feet of head per psi. This conversion is used constantly to translate elevations and gauge readings into one another.

Question 7Principles of backflow and cross-connection hydraulics

The critical level of an atmospheric vacuum breaker must be installed at least how far above the highest downstream outlet it protects?

  1. 12 inches
  2. 6 inches Correct answer.
  3. 3 inches
  4. 1 inch

Explanation

An atmospheric vacuum breaker is installed so its critical level sits at least 6 inches above the highest point of downstream piping or the highest outlet served. That elevation gives the air inlet room to break the siphon before the downstream water level can reach the device.

Question 8Principles of backflow and cross-connection hydraulics

Which assembly contains a relief valve that discharges to atmosphere when the pressure differential across its first check valve falls below approximately 5 psi?

  1. Pressure vacuum breaker assembly
  2. Reduced pressure principle assembly Correct answer.
  3. Atmospheric vacuum breaker
  4. Double check valve assembly

Explanation

The reduced pressure principle assembly uses a spring-loaded differential relief valve that opens when the pressure in the zone between the checks rises enough to reduce the first-check differential below the design set point. Discharge at the relief port is the visible evidence that the assembly is responding to a loss of supply pressure or to leakage through a check.

Question 9Principles of backflow and cross-connection hydraulics

As water accelerates through a narrowed section of pipe, its velocity increases and the pressure at that section:

  1. Remains constant because flow is steady
  2. Rises briefly and then falls to zero
  3. Increases in proportion to the velocity
  4. Decreases Correct answer.

Explanation

Conservation of energy requires that an increase in velocity head be matched by a decrease in pressure head, so pressure falls where the flow speeds up. This relationship is the reason a Venturi throat can develop a partial vacuum and draw a nonpotable liquid into a water line.

Question 10Principles of backflow and cross-connection hydraulics

The differential relief valve of a reduced pressure principle assembly is designed to open when the pressure differential across the first check valve drops below approximately:

  1. 20 psi
  2. 1 psi
  3. 5 psi Correct answer.
  4. 15 psi

Explanation

The relief valve is set to open when the differential across the first check falls to about 5 psi, a value that keeps the zone pressure at least 2 psi below the supply pressure during normal operation. If the supply pressure falls or a check leaks, the loss of differential opens the relief valve and protects the supply.

Question 11Principles of backflow and cross-connection hydraulics

The critical level of a backflow prevention device is:

  1. The elevation of the highest fixture served by the device
  2. The lowest point of the device's waterway that must be installed above the flood level rim Correct answer.
  3. The flow rate at which the check valve first opens
  4. The maximum pressure the device can withstand without damage

Explanation

The critical level is the manufacturer-marked elevation on a device, representing the lowest point of its waterway, that must be maintained above the flood level rim of whatever it protects. Installing the device so this mark sits above the flood level rim keeps the air inlet or vent in a position to break a siphon.

Question 12Principles of backflow and cross-connection hydraulics

A pressure vacuum breaker assembly will allow water to spill from its vent when:

  1. The outlet is capped and thermal expansion raises downstream pressure
  2. The supply pressure drops enough for the loaded check to open the air inlet Correct answer.
  3. Flow through the device exceeds its rated capacity
  4. A downstream booster pump raises pressure above the supply pressure

Explanation

The pressure vacuum breaker uses a spring-loaded check with an independently acting air inlet vent, and that vent opens only when the supply-side pressure falls toward atmospheric. Because it protects against backsiphonage only, water spilling from the vent is normally the sign of a pressure loss or a fouled check rather than normal flow.

Question 13Principles of backflow and cross-connection hydraulics

As flow rate through a check valve increases, the pressure drop across the valve:

  1. Falls to zero at rated flow
  2. Increases Correct answer.
  3. Decreases
  4. Remains equal to the static pressure

Explanation

Friction and turbulence losses through a valve rise with the square of the velocity, so greater flow always means a greater pressure loss. This is why residual pressure downstream of a backflow assembly can fall sharply during high-demand events such as fire flow.

Question 14Principles of backflow and cross-connection hydraulics

Which situation is most likely to create backsiphonage in a building's water system?

  1. A large fire flow demand that pulls main pressure below atmospheric Correct answer.
  2. A water heater's thermal expansion acting against a closed inlet check valve
  3. A chemical feed pump injecting into a boiler at 30 psi above main pressure
  4. A cooling tower located forty feet above the service connection

Explanation

A heavy demand such as fire flow can drop pressure in the main below atmospheric, producing a partial vacuum that draws nonpotable liquids toward the supply. The other listed conditions all raise downstream pressure, which produces backpressure instead.

Question 15Principles of backflow and cross-connection hydraulics

A water heater is installed with a check valve on the cold water inlet. As the water is heated, the closed system creates which condition?

  1. Cavitation at the inlet check valve
  2. A lowered critical level at nearby vacuum breakers
  3. Backsiphonage caused by a vacuum in the main
  4. Backpressure from thermal expansion Correct answer.

Explanation

Heating water in a closed system raises its pressure because the expanded volume has nowhere to go, and that elevated pressure pushes back toward the supply. The remedy is a thermal expansion tank or a relief device, since a check valve alone cannot prevent this backpressure.

Question 16Principles of backflow and cross-connection hydraulics

The rapid closure of a valve in a piping system produces a pressure surge that is commonly called:

  1. Vapor pressure
  2. Static head
  3. Laminar flow
  4. Water hammer Correct answer.

Explanation

Stopping a moving column of water suddenly converts its kinetic energy into a pressure spike that travels through the piping as a shock wave. The surge can be strong enough to damage meters and backflow assemblies, and it can momentarily drive pressures well above normal operating values.

Question 17Principles of backflow and cross-connection hydraulics

A pressure gauge on a pipe reads 5 psi. If a vertical tube open at the top were connected to that pipe, water would rise in the tube to approximately:

  1. 2.3 feet
  2. 11.6 feet Correct answer.
  3. 5 feet
  4. 23 feet

Explanation

Each psi supports about 2.31 feet of water column, so 5 psi will lift water roughly 5 times 2.31, or 11.6 feet. This same relationship explains why a sustained vacuum of only a few psi can pull water a considerable distance upward into a supply line.

Question 18Principles of backflow and cross-connection hydraulics

An atmospheric vacuum breaker is not permitted to be subjected to continuous supply pressure for longer than:

  1. 7 days
  2. 12 hours Correct answer.
  3. 24 hours
  4. 1 hour

Explanation

The standard limits an atmospheric vacuum breaker to no more than 12 hours of continuous pressure because a sustained pressure can hold the air inlet closed and defeat the device. Where longer duty is required, a pressure vacuum breaker or another assembly rated for continuous pressure must be used.

Question 19Principles of backflow and cross-connection hydraulics

Which assembly is required at a connection that poses a health hazard and is subject to both backpressure and backsiphonage?

  1. Double check valve assembly
  2. Atmospheric vacuum breaker
  3. Reduced pressure principle assembly Correct answer.
  4. Pressure vacuum breaker assembly

Explanation

A health hazard combined with a possible backpressure condition requires a reduced pressure principle assembly, which protects against both mechanisms and provides a visible discharge of water if a check fails. The lower-level devices either cannot handle backpressure or are limited to non-health-hazard service.

Question 20Principles of backflow and cross-connection hydraulics

In a reduced pressure principle assembly, the purpose of the second check valve is to:

  1. Establish the critical level above the downstream outlet
  2. Prevent downstream pressure from entering the zone between the checks Correct answer.
  3. Keep the relief valve closed during normal forward flow
  4. Admit air into the zone when a vacuum forms

Explanation

The second check isolates the intermediate zone from downstream pressure so that backpressure cannot reach the zone and hold the relief valve shut. If the second check leaks, downstream pressure enters the zone and the relief valve opens, which is what makes the discharge visible to the tester.

Question 21Principles of backflow and cross-connection hydraulics

A reduced pressure principle assembly in service with no downstream flow is discharging water continuously from its relief port. Which condition best explains this?

  1. The air inlet screen on the relief port is clogged with debris
  2. The second check is fouled open, allowing downstream pressure into the zone Correct answer.
  3. The downstream shutoff valve is closed tightly, isolating the assembly
  4. The supply pressure is unusually high, forcing the relief valve open

Explanation

A leaking or fouled-open second check lets downstream pressure enter the intermediate zone, which reduces the differential across the first check and drives the relief valve open. Higher supply pressure would tend to hold the relief valve closed, so the failure points to the second check or to a downstream source of pressure.

Question 22Principles of backflow and cross-connection hydraulics

The minimum air gap is specified as twice the diameter of the effective opening, with a minimum of one inch, mainly in order to:

  1. Stop the discharge pipe from dripping onto the floor after flow stops
  2. Leave room to install a test cock on the discharge pipe
  3. Keep a margin for splash and wave action so physical separation is always maintained Correct answer.
  4. Match the height of the flood level rim to the fixture's overflow

Explanation

The air gap must remain a true physical separation even when the receiving vessel is agitated, so the sizing rule builds in a margin for splash, wave action, and normal deterioration of the opening. The one-inch floor of the rule addresses very small openings where the two-times-diameter value would be negligible.

Question 23Principles of backflow and cross-connection hydraulics

At sea level, the theoretical maximum height to which a perfect vacuum could lift water is approximately:

  1. 62.4 feet
  2. 14.7 feet
  3. 33.9 feet Correct answer.
  4. 2.31 feet

Explanation

Atmospheric pressure at sea level is about 14.7 psi, and each psi supports roughly 2.31 feet of water, giving a theoretical lift of about 33.9 feet. Actual lift is always less because of friction and because a perfect vacuum cannot be achieved in a real piping system.

Question 24Principles of backflow and cross-connection hydraulics

During a static test of a reduced pressure principle assembly with no flow, a differential gauge across the first check reads 4 psi. What does this indicate?

  1. The gauge is actually reading the differential across the second check
  2. The assembly has failed because the differential is above the minimum
  3. The assembly is acceptable because any positive differential is enough
  4. The first check is not holding the required differential, so the relief valve should be discharging Correct answer.

Explanation

A properly functioning reduced pressure assembly maintains a first-check differential of at least 5 psi at no flow, which keeps the zone pressure safely below supply pressure. A reading of 4 psi shows the first check is not holding that differential, and the relief valve should be open and discharging.

Question 25Principles of backflow and cross-connection hydraulics

A boiler makeup water line has a chemical feed pump that can raise the line pressure above the building supply pressure. Which approach correctly addresses the hydraulic condition?

  1. Rely on the boiler's relief valve to prevent water from returning to the supply
  2. Install an atmospheric vacuum breaker ahead of the chemical feed pump
  3. Install a single check valve, since the chemical pump is downstream of the boiler
  4. Install a reduced pressure principle assembly at the connection to protect against backpressure Correct answer.

Explanation

The chemical feed pump can push boiler water backward whenever its pressure exceeds supply pressure, which is a toxic backpressure hazard. A reduced pressure principle assembly protects against backpressure with a health hazard and will discharge visibly if its checks fail.

Question 26Principles of backflow and cross-connection hydraulics

In backflow terminology, a cross-connection is best described as which of the following?

  1. A link between potable water and a contaminating source Correct answer.
  2. A mechanical joint used to connect two dissimilar piping materials
  3. A bypass pipe routed around a water meter to allow unmetered flow
  4. A control valve that separates two different fire sprinkler zones

Explanation

A cross-connection is any actual or potential connection through which nonpotable fluid could enter a potable water system, whether or not flow is currently reversed. Because the link can be potential rather than actual, protection must be installed before contamination occurs. Pipe joints, meter bypasses, and zone valves are ordinary plumbing components unless they create such a link.

Question 27Principles of backflow and cross-connection hydraulics

Backflow that occurs because pressure on the downstream side of a connection is greater than the supply pressure, with no vacuum involved, is called:

  1. Hydraulic jump backflow
  2. Backpressure backflow Correct answer.
  3. Induced siphonage backflow
  4. Backsiphonage backflow event

Explanation

Backpressure backflow is driven by a downstream pressure that exceeds the potable supply pressure, pushing water backward through the connection. Backsiphonage is a different mechanism, driven by negative or sub-atmospheric pressure on the supply side. Both are forms of backflow and both require an actual or potential cross-connection to cause harm.

Question 28Principles of backflow and cross-connection hydraulics

In a static body of water open to atmosphere, the gauge pressure at any point depends only on which of the following?

  1. The shape of the container walls
  2. The cross-sectional area of the pipe
  3. The depth below the free surface Correct answer.
  4. The total volume of water in the container

Explanation

Static pressure equals the product of the fluid's specific weight and the vertical depth below the free surface, so only depth and density matter. Container shape, total volume, and pipe diameter do not change the pressure at a given depth. This relationship explains why each foot of elevation produces the same pressure increment regardless of pipe size.

Question 29Principles of backflow and cross-connection hydraulics

Water moves at 2 ft/s through a 4-inch diameter pipe that reduces to a 2-inch diameter section. What is the velocity in the 2-inch section?

  1. 2 ft/s
  2. 4 ft/s
  3. 8 ft/s Correct answer.
  4. 1 ft/s

Explanation

The continuity equation states that flow rate equals area times velocity, and flow rate is constant through the reduction. Halving the diameter quarters the cross-sectional area, so the velocity must increase by a factor of four to carry the same flow. Thus 2 ft/s becomes 8 ft/s in the smaller section.

Question 30Principles of backflow and cross-connection hydraulics

If the flow rate through a given length of the same pipe is doubled, the friction head loss increases by a factor closest to which value?

  1. About four times as great Correct answer.
  2. About twice as great
  3. About eight times as great
  4. About 1.85 times as great

Explanation

Friction head loss rises faster than flow because the empirical exponents in common formulas, such as the Hazen-Williams exponent of about 1.85, exceed one. Doubling the flow raises the loss by roughly 2 raised to the 1.85 power, which is about 3.6, or approximately fourfold. This is why undersized or high-velocity piping causes disproportionately large pressure losses.

Question 31Principles of backflow and cross-connection hydraulics

Potable water in a supply line is exposed to a chemical that is toxic at very low concentrations. In standard backflow terminology, this exposure is classified as:

  1. A health hazard, or contaminant Correct answer.
  2. A nuisance hazard limited to color and odor
  3. A non-hazard below the level of detectability
  4. An aesthetic hazard, or pollutant

Explanation

A contaminant is a substance that, if introduced into potable water, would create a danger to public health, so toxicity at low concentration makes the exposure a health hazard. A pollutant, by contrast, degrades the water's appearance, taste, or odor without creating a health risk. The degree of hazard determines which type of backflow protection is required.

Question 32Principles of backflow and cross-connection hydraulics

A fill pipe discharges into an open chemical vat that has a fixed overflow rim. Which method provides the most reliable protection against backflow at this connection?

  1. A fixed air gap above the vat's overflow rim Correct answer.
  2. A reduced pressure assembly downstream of the outlet
  3. A pressure vacuum breaker at the outlet
  4. A double check valve assembly on the fill line

Explanation

An air gap is the only protection that relies on physical separation rather than mechanical parts, so it prevents both backpressure and backsiphonage regardless of supply pressure changes. For an open vat, the gap must be maintained above the overflow rim by at least the required distance. Mechanical assemblies can fail or be fouled, whereas an air gap cannot be defeated by pressure reversal.

Question 33Principles of backflow and cross-connection hydraulics

A garden hose is left with its nozzle submerged in a swimming pool. A large fire flow demand upstream drops the pressure in the service main well below atmospheric. Which result is expected at the hose connection?

  1. The main drains into the pool until the pressures equalize, with no reversal
  2. The pool water is held back because the hose outlet sits above the main
  3. Pool water is drawn through the hose into the potable main Correct answer.
  4. Pool water enters the main only if the hose has a vacuum breaker

Explanation

When the main pressure falls below atmospheric, the submerged hose end becomes a cross-connection and the pool water is siphoned backward into the potable system. This is backsiphonage, and it can occur even though the pool is at a higher elevation than the main. The submerged outlet removes the air break that would otherwise prevent reversal.

Question 34Principles of backflow and cross-connection hydraulics

A barometric loop roughly 35 ft high is installed in a supply line feeding an outlet. Which protection does this arrangement provide?

  1. Backpressure protection only; backsiphonage is not addressed
  2. Full protection equivalent to an air gap at the outlet
  3. Backsiphonage protection only; backpressure is not addressed Correct answer.
  4. Both backsiphonage and backpressure protection

Explanation

A barometric loop works because a vacuum cannot lift water over a column about 34 ft high at sea level, so backsiphonage is prevented up to that limit. It offers no barrier when downstream pressure exceeds supply pressure, since backpressure simply pushes water over the loop. It also is not a physical air gap, because the pipe remains continuous.

Question 35Cross-connection control regulations, codes and standards

In the United States, which entity has primary responsibility for enforcing cross-connection control requirements for public water systems?

  1. The American Water Works Association, through its member water utilities
  2. The International Code Council, which publishes model plumbing codes for adoption
  3. State and local authorities acting through the state drinking water primacy agency Correct answer.
  4. The federal Environmental Protection Agency, acting under the Safe Drinking Water Act

Explanation

The Safe Drinking Water Act sets national drinking water standards, but states and local agencies implement cross-connection control, often through the state primacy agency. EPA publishes guidance but does not directly enforce cross-connection control at individual premises.

Question 36Cross-connection control regulations, codes and standards

The term cross-connection refers to which of the following?

  1. A temporary hose used to fill a tank from a faucet
  2. A connection between two potable water mains at different pressures
  3. A connection between potable water and any nonpotable source Correct answer.
  4. A pipe that crosses over another pipe without making contact

Explanation

A cross-connection is any actual or potential link between a potable system and a nonpotable source. It creates the pathway through which backflow can introduce contaminants.

Question 37Cross-connection control regulations, codes and standards

A non-health hazard is best described as which of the following?

  1. A nuisance or aesthetic problem that is not a health risk Correct answer.
  2. Any condition that could cause serious illness, injury, or death
  3. A hazard that is found only in industrial or manufacturing facilities
  4. A hazard that is associated with fire sprinkler systems in buildings

Explanation

A non-health hazard creates a nuisance, aesthetic, or minor quality problem but is not expected to cause illness. Health hazards involve contaminants that can cause serious illness or death.

Question 38Cross-connection control regulations, codes and standards

Backsiphonage occurs when which condition develops?

  1. Supply pressure drops below atmospheric, creating a vacuum Correct answer.
  2. A pump pushes water backward through a check valve
  3. A thermal expansion tank pressurizes the piping system
  4. Downstream pressure exceeds the pressure in the supply main

Explanation

Backsiphonage is caused by a negative or sub-atmospheric pressure in the supply piping, which draws nonpotable water into the potable system. Backpressure occurs when downstream pressure exceeds supply pressure.

Question 39Cross-connection control regulations, codes and standards

What is the minimum air gap required for a potable water outlet discharging into a receptor?

  1. One-half inch regardless of the size of the pipe or outlet
  2. Four times the diameter of the pipe, with no minimum dimension
  3. Two inches or the pipe diameter, whichever dimension is greater
  4. Twice the effective opening diameter, but not less than one inch Correct answer.

Explanation

The minimum air gap is twice the diameter of the effective opening, with a minimum of one inch. This separation must be maintained above the flood level rim of the receptor.

Question 40Cross-connection control regulations, codes and standards

Under most state and local cross-connection control programs, how often must testable backflow prevention assemblies be field tested?

  1. Every six months
  2. Annually Correct answer.
  3. Monthly
  4. Every five years

Explanation

Most jurisdictions require annual field testing of testable assemblies such as RPZs, DCVAs, PVBs, and SVBs. The tester must be certified and the results reported as required.

Question 41Cross-connection control regulations, codes and standards

ASSE 5110 is a professional qualification standard that establishes requirements for which of the following?

  1. The installation of air gaps in plumbing systems
  2. The design of reduced pressure principle assemblies
  3. The certification of backflow prevention assembly testers Correct answer.
  4. The manufacture of double check valve assemblies

Explanation

ASSE 5110 sets minimum qualifications for certifying backflow prevention assembly testers, including knowledge, testing skill, and code familiarity. It is a personnel qualification standard, not a product standard.

Question 42Cross-connection control regulations, codes and standards

An atmospheric vacuum breaker is approved for use only where which condition exists?

  1. A pump can create backpressure downstream
  2. The downstream piping is under constant pressure
  3. The device is installed below grade in a vault
  4. No backpressure exists and flow is not continuous Correct answer.

Explanation

An AVB is a non-testable device approved only for backsiphonage protection. It must not be installed where backpressure can occur or where it is under continuous pressure.

Question 43Cross-connection control regulations, codes and standards

A hospital connects a laboratory sink to the potable water system. The sink has a threaded faucet and could be submerged. Which is the minimum acceptable protection for a health hazard that may experience both backsiphonage and backpressure?

  1. A hose connection vacuum breaker at the faucet
  2. An atmospheric vacuum breaker installed at the sink
  3. Reduced pressure principle backflow prevention assembly Correct answer.
  4. A double check valve assembly on the branch line

Explanation

A health hazard that can experience both backsiphonage and backpressure requires an RPZ or an air gap. An AVB and a hose connection vacuum breaker protect only against backsiphonage, and a DCVA is limited to non-health hazards.

Question 44Cross-connection control regulations, codes and standards

A commercial building has a fire sprinkler system containing only water and no chemical additives. The system is a non-health hazard and backpressure is possible. Which assembly is the minimum appropriate protection?

  1. Double check valve assembly Correct answer.
  2. Atmospheric vacuum breaker
  3. Pressure vacuum breaker assembly
  4. Reduced pressure principle assembly

Explanation

For a non-health hazard with possible backpressure, a double check valve assembly is the minimum acceptable protection. An RPZ is more protective but is not the minimum required.

Question 45Cross-connection control regulations, codes and standards

A pressure vacuum breaker is installed on an irrigation system. Which condition makes this installation unacceptable?

  1. The PVB is tested annually by a certified tester
  2. The downstream piping is subject to backpressure from a booster pump Correct answer.
  3. The PVB is protecting a health hazard
  4. The PVB is installed 12 inches above the highest downstream outlet

Explanation

A PVB is approved for backsiphonage only and must not be subjected to backpressure. A booster pump downstream can create backpressure and makes the installation unacceptable.

Question 46Cross-connection control regulations, codes and standards

What advantage does a spill-resistant vacuum breaker have over a standard pressure vacuum breaker?

  1. It operates under continuous pressure without spilling Correct answer.
  2. It provides protection against backpressure
  3. It does not require annual field testing
  4. It can be installed below grade in a vault

Explanation

An SVB is designed to operate under continuous pressure and to resist spilling water when the air inlet opens. Like a PVB, it protects against backsiphonage, not backpressure.

Question 47Cross-connection control regulations, codes and standards

A double check detector assembly is typically used for which application?

  1. Non-health fire systems where small flows are metered Correct answer.
  2. Health-hazard fire sprinkler systems that contain antifreeze
  3. Irrigation systems that have a booster pump downstream
  4. Laboratory sinks that have threaded faucets

Explanation

A DCDA is a double check assembly with a metered bypass, used on non-health-hazard fire systems to detect small unauthorized flows. Health-hazard fire systems, such as those with antifreeze, require an RPDA.

Question 48Cross-connection control regulations, codes and standards

After field testing a backflow prevention assembly, the certified tester should take which action?

  1. File the report with the authority and give a copy to the owner Correct answer.
  2. Keep the report confidential and provide it only to the building owner
  3. Post the test results at the service connection for public inspection
  4. Discard the report after 30 days because the testing has been completed

Explanation

Test reports document that the assembly performed to standard and are used by the water purveyor or health authority to track compliance. The tester must submit the report as required and provide a copy to the owner.

Question 49Cross-connection control regulations, codes and standards

A water utility requires a backflow preventer at each customer's service connection. This approach is called which of the following?

  1. Premises containment Correct answer.
  2. Internal isolation
  3. Point-of-use isolation
  4. Cross-connection elimination

Explanation

Premises containment places protection at the service connection so the building cannot contaminate the public main. Point-of-use isolation protects fixtures inside the building but does not protect the distribution system.

Question 50Cross-connection control regulations, codes and standards

Which section of the International Plumbing Code addresses protection of the potable water supply from cross-connections?

  1. Section 608, potable water protection Correct answer.
  2. Section 903, Fire Sprinkler Systems
  3. Chapter 10, Traps and Interceptors
  4. Chapter 3, General Regulations

Explanation

IPC Section 608, Protection of Potable Water Supply, contains the cross-connection and backflow prevention requirements. It addresses air gaps, backflow assemblies, and device installation.