Red Seal Gasfitter — Class B Practice Exam

How should gas pipe joints be properly sealed?

1. With duct tape

2. With paint

3. With approved tape or thread sealant

4. With glue

The correct answer is: With approved tape or thread sealant

Gas pipe joints must be properly sealed to ensure that there are no leaks, which can pose significant safety hazards. Using approved tape or thread sealant is the standard practice because these materials are specifically designed to create a secure, airtight seal on the threaded connections between gas pipes. Approved tape or thread sealant is typically resistant to hydrocarbons, which include natural gas and propane, ensuring durability and effectiveness under the conditions these gases may present. This type of sealing method helps avoid the risks of gas escaping from the joint due to loose or poorly secured fittings. In contrast, other options do not meet safety and regulatory standards. Duct tape is not rated for use with gas and does not provide a consistent seal that can withstand pressure and temperature variations. Paint is not a sealing agent and does not provide any functional sealing capability for gas pipes. Glue, while it may seem like it could provide a seal, is not appropriate for threaded joints and can actually react negatively with certain types of pipe materials or gas. Thus, using approved tape or thread sealant is the only method that ensures reliability, compliance with safety standards, and the integrity of gas piping systems.