Pipe Joining and Fitting Methods Flashcards

When joining ABS or PVC drain pipe with solvent cement, what motion is used when inserting the pipe into the socket?

Answer: Give the pipe a quick quarter-turn while pushing to full depth, then hold without rotation

A quarter-turn during insertion distributes the cement evenly across the bonding surfaces and achieves correct alignment; holding the joint prevents it from backing out while the cement sets.

What is the correct sequence of operations when cutting and threading steel pipe on a power threading machine?

Answer: Cut to length, ream the inside, thread, apply sealant, then assemble

Cutting first ensures proper length; reaming after cutting removes the internal burr created by the pipe cutter; threading follows reaming, and sealant is applied just before assembly.

What is the approximate pressure rating of 1-inch Schedule 40 PVC pipe at 23°C for cold water service?

Answer: Approximately 690 kPa (100 psi), with the rating decreasing as temperature rises

Schedule 40 PVC is rated near 690 kPa (100 psi) at room temperature, but this rating drops significantly with increasing temperature, which is why it cannot be used on hot water supply lines.

When soldering a copper fitting, where should the heat from the torch primarily be directed?

Answer: To the fitting body, allowing capillary action to draw solder fully into the joint

Heating the fitting body warms the entire joint assembly so that when solder contacts the pipe-fitting interface, capillary action pulls the molten solder completely into the gap.

In which direction should PTFE thread tape be wound around male pipe threads before making a connection?

Answer: Clockwise when viewed from the threaded pipe end, in the direction of thread engagement

Applying PTFE tape clockwise (in the direction the fitting will be threaded on) ensures the tape seats into the threads during assembly rather than unravelling as the fitting is tightened.

What is the minimum cure time before a solvent-cemented CPVC hot water line may be pressure tested in warm conditions (above 15°C)?

Answer: Follow manufacturer specifications — typically a minimum of 1 hour before low-pressure test and 24 hours before full system pressure

Solvent cement creates a chemical weld that requires initial set time before handling and full cure before pressure testing; premature pressurization will cause joint failure.

Which type of coupling allows pipes of different outer diameters or materials to be joined in a drain system without threading or solvent cement?

Answer: A banded rubber (Mission/no-hub-type) coupling with stainless steel clamp bands

Banded rubber couplings use a flexible neoprene sleeve and stainless steel bands to join pipes of differing sizes or materials, making them ideal for connecting new plastic pipe to existing cast iron or clay sewer pipe.