How to Apply PTFE Thread Seal Tape

P.T.F.E. thread sealing tape is ideal for making a watertight connection on metal fitting NPT pipe joints.

WARNING: P.T.F.E. (Teflon) thread seal tape is not recommended for making NPT threaded connections when using Schedule 40 or 80 PVC threaded pipe fittings! Wrapping P.T.F.E. tape adds bulk and lubricates the joint, both of which increase the risk of cracking the female PVC fitting.

PREPARATION: Before wrapping the pipe thread make sure the threads are not damaged, are clean, and free of foreign debris.

Holding the fitting or nipple in your left hand apply P.T.F.E. thread sealant tape to the male threads. Hold the end of the tape securely in place using your thumb. Pull the tape tight so that it forms into the threads and start wrapping in the direction of the threads (clockwise for right hand threads). Wrapping the pipe in the opposite direction that you will screw it into the fitting will prevent the tape from unraveling during assembly.

Start the first wrap by ensuring the tape fully covers the end of the thread, partially wrapping around the end of the fitting, but not covering the opening. Wrapping the entire thread will reduce the risk of seizing or galling prior to proper joint make up.

Maintain tension on the tape, ensuring that it is snugly wrapped around the thread and forms into the thread profile. Wrap the tape 3-5 revolutions and overlap the tape. Work gradually away from the end of the thread to completely cover the thread.

When you have finished wrapping, grip the tape with your thumb and forefinger, then pull it sharply to break the end of the tape from the spool. Then smooth the loose end of the tape over the threads so nothing is sticking up or bunched up.

TIP: After you are done wrapping you can use the edge of the spool to chase the threads forming the tape into the thread profile. This will prevent any bunching or binding when you tighten up the pipe.

You are now ready to thread the pipe into its fitting!

Thread seal tape and thread sealing compound can be used in conjunction with one another.

Once you have the male threads properly wrapped with P.T.F.E. thread seal tape, you can apply a coating of thread sealing compound over the PTFE tape before assembling the connection. Due to NPT tapered thread designs on pipes and fittings, the tape will be compressed into the root of the thread. Since the tape’s elasticity allows it to stretch when applied, it does not completely fill the root to the crest of the thread. Applying a thread seal compound such as GRAY MAGIC on top of the tape will fill any remaining voids between the male and female threads as they are assembled. Excess joint compound will be pushed out of the fitting.

https://support.boshart.com/making-npt-connections

https://support.boshart.com/making-a-leak-proof-stainless-steel-threaded-connection

https://support.boshart.com/gray-magic-applications