What is the purpose of pipe thread sealant or Teflon tape?

• A. To color-code joints
• B. To clean threads
• C. To lubricate threads for loosening
• D. To seal threads and prevent leaks

Answer: (D)

Sealing threaded joints to prevent leaks is what pipe thread sealant and Teflon tape are for. They fill the tiny gaps between mating threads so fluids can’t escape as the joint is tightened. They also provide a little lubrication to help the threads turn smoothly and reduce galling during assembly, but the key purpose is preventing leaks, not color-coding joints, cleaning threads, or making the connection easier to loosen. Use them correctly by applying the tape or sealant to the male threads in the direction of tightening and with the appropriate amount for the fitting type.