The use of Teflon tape is widespread and it’s definitely one of the greatest products since the early ‘70s. However, there is some limitation to it as well.
You must know when not to use Teflon tape like in PVC fittings o valves with FPT (Female threads) to avoid stress on the joins and eventually leaks.
Using it on fluid fittings results in several unwanted scenarios. I have seen lots of confusion about the Teflon tape applications on several message boards and forums.
As I am interested in everything related to the bathroom, I have decided to write about this product more elaborately to clear those confusions once and for all.
Stay with me for a while.
Cases Where Teflon Tape Should Not Be Used
When it comes to using something as a sealant and lubricating material, Teflon tape is second to none. Almost all of your bathroom and kitchen fittings require using this tape.
However, avoid using Teflon tape in the following circumstances:
- Don’t Use It On PVC Threads/Plastic Fittings
Teflon tape is designed to be used with metal pipes and fittings. It was never intended to be used with plastic fittings and you should not use it with any of your plastic fittings.
If you do, it will add strain and tensile stress. Let’s explain a little bit more.
The reason you should not be using it on PVC fittings with FPT (Female Thread) is that it will make the threaded joints slippery.
That will result in over-torque and ultimately lead to cracks and leaks. So, instead of Teflon tape, you should non-hardening sealant that won’t add any slipperiness.
- Never Use It On Hydraulic Fittings
Should you use Teflon tape on hydraulic fittings?
No! Teflon tape is not designed to be used on any hydraulic fittings.
Using such tape won’t create the perfect seal on connections and eventually fail because Teflon tape was never intended to be used for such kind of pressures.
In fact, you can’t use pipe dope on hydraulic fittings either. Yes, there are some clear differences between Teflon tape and pipe dope!
- Don’t Use Teflon Tap On PVC to Brass
First of all, PVC, brass, and Teflon tape are not designed to work together. For such kind of task, you need male PVC to the female hard pipe.
- On Oxygen Fittings
To be more precise, you can use Teflon tape (Green color) on oxygen fittings only if it is lubricant-free. And it should never be used without a professional.
For most households, don’t try to use it on oxygen fittings if you don’t have the necessary experience.
Frequently Asked Questions (FAQs)
Yes. Polytetrafluoroethylene is the short form of PTFE and Teflon is the brand name. But both of them refer to the same thing.
When you need to connect your faucets to the water supply lines, you should use Teflon tape (Pink color) to seal and lubricate threaded pipe joints.
To create a leak-free seal, you should use Teflon tape on NPT fittings. Without any sealing compound like Teflon tape, using NPT will lead to various unpleasant issues like leakage.
It has many usages. But plumber’s tape or Teflon tape is widely used to seal pipe threads.
No, it’s not OK to use Teflon tape on PVC threads. Using this tape on PVC fittings will result in over-torque which will lead to cracks and other unpleasant scenarios.
Yes, you can use Teflon tape (Yellow color) on all types of gas lines. But you need to use gas-rated Teflon tape for that purpose. Such Teflon tape is thick and can withstand negative 450 to 550 degrees Fahrenheit.
Yes, you can use Teflon tape on stainless steel threads to prevent galling and seizing.
Yes, when applied improperly, Teflon tape can cause leaks. By improperly I mean adding too much tape.
Closing Remarks
There are some good reasons why Teflon tape is also known as Plumber’s tape. Plumbers use it almost all the time. It should be in everyone’s house even if you are not a DIY enthusiast.
However, make yourself familiar with when not to use Teflon tape and what are the alternative of it. The wrong application will eventually lead to cracks, leaks, and many other unpleasant issues.
Doesn’t mention if one pipe is iron and fitting is PVC, have used Teflon tape this way and lasted 40 years.