2nd year plumbing theory. code book 2.6

On a fixture with separate hot and cold water controls, which side should the hot water control be on?

The hot water control must be on the left, and the cold water control must be on the right.

a hot water system over ___ M or ____ stories should have ?

a recirc or self regulating heat trace system

A water distribution system should be installed so the system can be ?

Drained or blown out with air

Where should the shut-off valve be located on a water service pipe?

As close as possible to where the pipe enters the building.

where should shut-off valves be placed for gravity tanks or private water supplies?

At the source of supply.

Do risers require shut-off valves? where is the shut off valve?

• yes, unless it serves only one dwelling unit.

• Shut-off valves must be located at the source of supply.

Do water closets require a shut-off valve?

Do water closets require a shut-off valve?

In multi-unit residential buildings, where must shut-off valves be placed?

At the water supply entry to each unit, so shutting off one unit does not affect others.

In non-residential buildings, where must shut-off valves be installed?

On the water supply to:

1. Every fixture, or

2. Any group of fixtures in the same room (except water closets).

Do water heaters require a shut-off valve?

yes

What must be installed on pipes passing through an exterior wall to supply water outside a building?

Pipes must have either:

1. A frost-proof hydrant, or

2. A stop-and-waste cock located inside the building and close to the wall.

When is a check valve required at the building end of a water service pipe?

A check valve must be installed if the pipe is plastic and suitable for cold water use only.

What is required of flushing devices for water closets and urinals?

They must have sufficient capacity and be adjusted to deliver enough water to thoroughly flush the fixture(s).

How many fixtures can a manually operated flushing device serve?

Only one fixture.

What requirement must water closets and urinals meet regarding water usage?

Toilets and urinals must have a built-in limit on water usage per flush

What is the maximum water usage allowed for single-flush water closets in residential retrofits?

A maximum of 6.0 Lpf is permitted if 4.8 Lpf is does not work

When must flush-tank urinals have a device to prevent flushing when not in use?

Always, except in buildings not occupied year-round.

A storage-type water heater must have a pressure-relief valve that?

1. opens at the tank’s pressure limit and prevents pressure from exceeding the valve by more than 35 kPa.

A storage-type water heater must have a temperature-relief valve with a?

sensor located within 150 mm from the top that opens to prevent the water from exceeding 99°C.

Pipes from relief valves must:

• Be at least the same size as the valve outlet.

• Be rigid, sloped downward, and end above a drain or safe location with a ≤300 mm air break.

• Have no threads at the outlet.

• Withstand at least 99°C.

Can a shut-off valve be installed between a tank and its relief valves?

No, shut-off valves are not allowed on the pipe between the tank and the relief valves or their discharge lines.

When must a vacuum-relief valve be installed on a water heater?

If the tank may be subject to back-siphonage.

When must a storage-type service water heater be installed in a drain pan?

If it is located in a ceiling, roof space, or over a wood floor.

What are the requirements for a drain pan under a water heater?

• At least 50mm larger than the tank, with 25mm high sides.

• Drained by a pipe two NPS sizes larger than the relief valve discharge pipe.

• Drain located directly under the relief valve discharge pipe, leading to an acceptable drain.

How must a water distribution system be protected from water hammer?

Provision must be made to prevent the adverse effects of water hammer

What are the requirements for a water service pipe serving a mobile home?

• Be at least NPS ¾ in size.

• Terminate above ground.

• Have:

  • Tamperproof terminal connection (reconnectable, sealable).

  • Protective concrete pad.

  • Frost heave protection.

  • Curb stop and a way to drain above-frost-line pipes when not in use.

What components must be protected where thermal expansion can occur?

Protection must be provided for:

1. Check valves (Article 2.6.1.5).

2. Backflow preventers (Sentence 2.6.2.1.(3)).

3. Pressure-reducing valves (Article 2.6.3.3).

What temperature must thermostat controls be set to for electric storage-type service water heaters?

They must be set at 60°C.

How must connections to potable water systems be designed?

They must prevent non-potable water or harmful substances from entering the system.

When can a water treatment device be installed in a potable water system?

Only if it does not introduce substances that may endanger health.

How must potable water connections be installed to prevent back-siphonage?

They must prevent back-siphonage in accordance with required protection methods.

What are the approved methods to prevent back-siphonage? (11)

• Air gap

• Atmospheric vacuum breaker

• Pressure vacuum breaker

• Spill-resistant pressure vacuum breaker

• Hose connection vacuum breaker

• Dual check valve backflow preventer with atmospheric port

• Double check valve assembly

• Reduced pressure principle backflow preventer

• Dual check valve backflow preventer

• Laboratory faucet type vacuum breaker

• Dual check valve backflow preventer with vent

How must potable water connections be arranged when subject to pressure above atmospheric?

They must prevent backflow due to back pressure in accordance with regulations.

What methods prevent backflow of non-toxic substances into a potable water system?

1. Air gap

2. Dual check valve backflow preventer with atmospheric port

3. Dual check valve backflow preventer

4. Dual check valve backflow preventer with vent

5. Double check valve assembly

6. Reduced pressure principle backflow preventer

What methods prevent backflow of toxic substances into a potable water system?

• Air gap

• Reduced pressure principle backflow preventer

When is a backflow preventer not required in a fire sprinkler/standpipe system?

A full flow-through residential fire sprinkler/standpipe system does not require a backflow preventer if all pipes and fittings are made of potable water system materials.

What protection is required for Class 1 fire sprinkler/standpipe systems without additives?

If all pipes and fittings are potable water system materials, they must have either:

• Single check valve backflow preventer (CSA B64.9 - SCVAF), or

• Dual check valve backflow preventer (CSA B64.6 - DuC).

What additional protection is required for buildings with a severe health hazard risk from backflow?

A reduced pressure principle backflow preventer (RP) must be installed for premise isolation in addition to other required backflow preventers.

How must a public water supply system be protected when supplying a private water supply or non-potable water system?

It must be protected in accordance with Article 2.6.2.1 to prevent contamination.

How must a potable water system be protected when a hose bibb is installed outside, in a garage, or in a contamination-risk area?

The system must be protected against backflow through the hose bibb

What are the requirements for air gaps in a potable water system?

Air gaps must not be located in a noxious environment.

The minimum air gap must be 25 mm and at least twice the diameter of the water supply outlet.

What are the installation requirements for vacuum breakers?

• If the critical level is not marked, it is taken as the lowest point on the device.

• Atmospheric vacuum breakers (AVBs) must be:

  • Installed downstream of the fixture control valve.

  • Pressurized only when the valve is open and for no more than 12 hours.

  • Positioned at least 25 mm above the flood level rim or highest open point in an irrigation system.

• Pressure vacuum breakers (PVBs) and spill-resistant pressure vacuum breakers (SRVBs) must be installed at least 300 mm above the flood level rim or highest open point.

What is prohibited in a water supply system to ensure backflow preventer effectiveness?

No bypass piping or device that could reduce the effectiveness of a backflow preventer shall be installed.

How is the hydraulic load of a fixture determined?

• Listed fixtures → Use the fixture unit values from Table 2.6.3.2.-A.

• Unlisted fixtures → Use the values from Table 2.6.3.2.-D.

• Fixtures with both hot & cold water → Use 75% of the fixture unit load (if using detailed engineering design).

• Urinals & water closets with direct flush valves → Use the fixture unit values specified for them.

When is a pressure-reducing valve required in a water distribution system?

A pressure-reducing valve must be installed when the static pressure at any fixture exceeds 550 kPa to ensure the maximum pressure remains at 550 kPa or lower.

What is the minimum nominal pipe size (NPS) for water service pipes?

NPS ¾

What is the exception for fixtures permitted to have an NPS ⅜ supply pipe?

A connector up to 750 mm long and not less than NPS ¼ may be used.

What is the minimum nominal pipe size for water systems between the connection point and the first distribution pipe to a water heater serving multiple fixtures?

NPS ¾

Under what conditions can a water system in a residential building with one or two dwelling units be sized

Hydraulic loads must be at least 100% of the total hydraulic load of fixture units in relevant tables.
b) Minimum water pressure at the building entry must be 200 kPa.
c) The total maximum length of the water system must not exceed 90 m.

What determines the maximum permitted water velocities in a piping system?

The velocities must not exceed those recommended by the pipe and fitting manufacturer.