National Plumbing Code of Canada Flashcards

According to the Code, what is the maximum interval between cleanout access points on a horizontal drainage pipe?

Answer: 15 m

Cleanouts must be installed at intervals not exceeding 15 m on horizontal drainage runs to allow access for clearing blockages with standard drain-cleaning equipment.

What test pressure is required for a DWV system rough-in test using water according to the Code?

Answer: A column of water at least 3 m high or 30 kPa

The Code requires a water test of at least 3 m head (approximately 30 kPa) held for 15 minutes to verify the integrity of all joints and connections in the DWV system.

What does the Code require for a cleanout at the base of every soil or waste stack?

Answer: A cleanout the same size as the stack, up to 4 inches

The Code requires a cleanout at the base of each stack that is the same size as the pipe, up to a maximum of 4 inches, to allow rodding access.

According to the National Plumbing Code of Canada, what is the minimum clearance in front of a water closet?

Answer: 550 mm

The Code requires a minimum clearance of 550 mm in front of a water closet to provide adequate user access and comfort.

What minimum air gap is required between a faucet outlet and the flood level rim of a fixture?

Answer: Two pipe diameters or 25 mm, whichever is greater

The Code requires an air gap of at least two pipe diameters or 25 mm, whichever is greater, to prevent cross-connection and backflow contamination.

What type of backflow preventer does the Code require for a high-hazard cross-connection?

Answer: Reduced pressure principle (RP) assembly

A reduced pressure principle (RP) backflow assembly is required for high-hazard cross-connections because it provides the highest level of protection with a relief valve that discharges to atmosphere if either check valve fails.