306A Pipe Joining and Fitting Methods

Question 1

What type of solder is required for copper joints in potable water systems under the National Plumbing Code of Canada?

Accepted Answer

Lead-free solder containing no more than 0.2% lead

Answer

50/50 tin-lead solder

Answer

Silver solder only

Answer

60/40 lead-tin solder

Question 2

After cutting rigid PVC pipe with a hacksaw for a solvent-cemented joint, what must be done to the pipe end before applying primer?

Accepted Answer

Deburr and chamfer the pipe end to ensure full insertion and avoid scraping cement from the socket

Answer

Apply solvent cement before deburring to seal the saw marks

Answer

Heat the pipe end with a heat gun to smooth the cut surface

Answer

Sand the outside only without touching the pipe bore

Question 3

What is the standard taper for NPT (National Pipe Taper) threads used on steel pipe fittings?

Accepted Answer

1 in 16 measured on the pipe diameter (3/4 inch per foot)

Answer

1 in 8 measured on the pipe diameter

Answer

1 in 12 measured on the pipe diameter

Answer

1 in 32 measured on the pipe diameter

Question 4

When making a crimp-ring connection on PEX tubing, which tool verifies that the crimp ring has been correctly compressed?

Accepted Answer

A go/no-go gauge that measures the outer diameter of the crimped ring

Answer

A torque wrench set to manufacturer specification

Answer

Visual inspection of the crimp ring profile only

Answer

A micrometer to measure the pipe wall thickness after crimping

Question 5

Which type of flux must NOT be used when soldering copper pipe in a potable water system?

Accepted Answer

Acid (active) flux containing zinc chloride

Answer

Lead-free water-soluble flux

Answer

Petroleum-based non-acid flux approved for plumbing

Answer

No-clean flux approved for copper water piping

Question 6

When connecting copper pipe directly to a galvanized steel fitting, what type of connector prevents galvanic corrosion at the joint?

Accepted Answer

A dielectric union that electrically isolates the two dissimilar metals

Answer

A standard brass coupling

Answer

A threaded brass nipple with PTFE tape

Answer

Direct threaded connection sealed with pipe dope is acceptable

Question 7

When preparing copper pipe for a push-fit (SharkBite-type) fitting, what is the most critical preparation step?

Accepted Answer

Cutting the pipe square and removing all burrs from the pipe end

Answer

Applying flux to the pipe end before insertion

Answer

Bevelling the pipe end at 45 degrees for easier insertion

Answer

Pre-heating the fitting body to expand it before inserting the pipe