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How to Apply Teflon Tape and to Apply It Correctly DIY

Knowing how to apply teflon tape correctly is important but also is using the right kind of teflon tape is important.

In this post I am going to show you how to apply teflon tape correctly and also what kind to use. In case you didn’t know there are many kinds of teflon tape and they each have there own purposes.

Most tapes come in white color, but there are multiple colors that correspond to coded pipelines (in most English-speaking countries, it equals to yellow for natural gas, green for oxygen etc.

Such color codes for plumbers’ sealing tapes were launched by Bill Bentley of Unasco Pty Ltd almost 50 years ago. The most common categorization of Teflon tapes colors are:

  • White: white tapes are used on American National Standard Pipe Thread, often called National Pipe Thread (NPT), for threads up to 3/8 inch.
  • Yellow: yellow tapes are used on NPT threads of 1/2 inch to 2 inch, often referred to as gas tape.
  • Pink: pink tapes are safer used for potable water and is used also on 1/2 inch to 2 inch NPT threads.   
  • Green: green tapes provide oil-free PTFE which are used on oxygen threads or some specific glasses used for medical purposes.   
  • Grey: tapes that come in grey color contain nickel and possess anti-corrosion, anti-seizing and anti-galling properties; they are best indicated for stainless pipes.
  • Copper: copper-colored tapes are made with granules of copper; this type of tape is recognized as a lubricant for threads, but not a sealer.   
  • Blue: blue Teflon tapes can be less common; they tend to be thicker and denser and are destined to general use

Teflon Or Plumbers Tape Can Be Found In A Lot Of Places

If you were to dismantle the gas and water pipes in your house, you would find that the edges of most pipes are covered in tapes. Don’t worry, it’s not there to fix anything broken: your pipes are fine. The tape, named Teflon tape, plumbers‘ tape or plumber’s seal tape, is there to stop pipes from leaking over time.

Coming in different widths, colors and thickness, Teflon tape is a film tape made of polyethylene (PTFE) commonly used as an alternative to hemp to seal pipe threads.    It is normally sold on a spool, making it a simple job to wind it around the pipe’s edges. The friction between surfaces is reduced thanks to the tape’s lubricant elements, allowing the threads to sit deeper and preventing them from seizing when unscrewed.

It is easier to tighten the joints as the tape also fills the threads and lubricates them; this also helps the sealing process without hardening the threads.  What It Is For: Features And Advantages Of Teflon Tape  Teflon tape is commonly used for all kinds of pipes’ sealing: applications include central heating system, air compression equipment and pressurized water systems.

According to Wikipedia the tape resists through any temperature: it will sit intact from -450F (around -270C) to +500F (+260C). PTFE elements are stable up to +500F (+260C), but it will start to decompose above +750F (+400C) and in contact with open fire, to which the tapes are not designed to resist. Although it is good for most purposes, the thread tape generally works best on tapered threads, as the sealing force works with a wedge action. 

Different types of tapes suit best different types of pipes and their purposes. For instance, tape used for gas fittings (for the gas regulations in UK) needs to be thicker than tape used for water. Unlike hemp, Teflon tape is less likely to cause leaking due to dried out material as it has better resistance to heat.

It is also required to know the grade of the tape, despite PTFE itself being fit for high-pressure oxygen situations; this will prevent any issues with grease.    In the United States, there are two different standards to determine the quality of a Teflon tape:   MIL-T-27730A: despite being a very antique military specification, it is still commonly used to refer to a tape with a thickness of 3.5 mils and above and the purity of the PTFE must be equal to or above 99%.  A-A-58092: this is a commercial grade used for tapes that keep the same thickness requisites of the MIL-T-27730A, with the exception that it adds a density level of 1.2 g/cm3 and above. Any other further specifics of some relevance may vary depending on the brand.   –

How to apply teflon tape

Apply it correctly: the secret to avoid failure and leaking over the years   There are a few rules on how to apply the Teflon tape correctly. A perfect application is essential in order to ensure that the pipes don’t start leaking over time.  

Wrap the tape in clockwise direction. It is very important to face the edge of the pipe you want to tape and wrap it clockwise. If you wrap the tape in the opposite direction, the tape will bunch up and peel as you screw it, losing adherence and permitting substances to leak.

The stray bits of tape that will form up will end up in the pipeline while the pipes are being connected. That will result in clogs and weaker pressure, caused by the tape blocking the flow of water and/or gas. Not to mention, screwing the pipe will become harder.

If you test the pipe with some water, you will most likely notice some dripping. On the contrary, if you wrap the tape clockwise, you will find that the pipe screws in nicely and easier. The tape will not ruin as it rubs against the female connector and stays intact, granting proper sealing of the pipes.

Over time, pipes properly sealed using this method are less likely to end up leaking or dripping. The best method of application is to attach the first bit to the edge of the pipe and unroll it around the whole part; this will grant a tight fit around the threads.

The third time is the charm

It is recommended to test the pipe to make sure it was properly sealed.   Wrap it 3 times to ensure proper sealing. Three is the recommended amount of turns the tape should make around the edge of the pipe.

Some may experience leaking over time and blame it on the tape, but another factor that must be considered is how tight the connector is placed on the pipe. In fact, the tape alone is not enough to ensure proper sealing: it must be paired with a tight connector.   

Therefore, if during the testing you realize that the pipe is still dripping, try screwing it a little further: the stronger the grasp, the least likely it is to cause leaking issues. Depending on the width and the thickness of the tape, you may also be able to apply a few more turns.

However, it is not recommended and you should not apply more than six turns.  

I bet you didn’t know you had to seal it 🙂

Seal it by wrapping up to the first thread and not further. In order to make the screwing process a bit faster, a pro tip would be to make sure the tape doesn’t go further than the first thread of the pipe’s very edge.

This will make the application of the connector much easier, as the tape will not apply any friction on top of the pipe’s edge. If you think you wrapped the tape too high up, you can try and test the pipe by screwing it into the female connector.

If you feel that it gets too hard to turn it, you can just take the tape off and do it all over again. You should be careful not to wrap the tape too far below the first thread, as it still needs to ensure proper sealing. Test the pipe multiple times to make sure it gets the job done.

Clean the pipe with a cloth before applying the tape. This can be risky, as the threads need to be completely dry to ensure that the tape’s adherence to the threads. Tape applied on wet threads may compromise the durability of the sealing.   

However, it is a very important step, as it removes dirt, grimes, and any other unwanted material that may impede the connection to be tight enough. It is recommended to thoroughly clean both pipes, the male and the female one.  

Pick the right width, color and thickness. Teflon tapes come in different modalities for a reason: different tapes go for different pipes. Thickness can vary depending on the launching brand, but it is usually found from 0.003 up to 0.020, although some industries may provide much thicker tapes.

When Not To Use Teflon Or Plumbers Tape

When Not To Use Teflon Or Plumbers Tape? Instances Where Teflon Tape Is Not Indicated  There can be many circumstances where Teflon tape must be used carefully, as overuse or misapplication may turn out to be dangerous.

Excessive wraps of the tape around the pipe’s edge will make it difficult for threads to engage completely; consequently, the shear point of the threads will be reduced. Also the use of a thread compound in addition to the thread-seal tape can overload threads.   

Joints or sloughs may be constricted off by loose materials overhanging internally, encouraging the formation of a foreign body that may jam a valve seat. Following this logic, it is therefore not always recommended to use Teflon tape to seal threads of pipes that are meant to be part of fluid power or hydraulic systems. 

Teflon tape is recommended for NPT and NPTF (National Pipe Taper Fuel) threads only. These can be recognised by their tapered threads. On the other hand, Teflon tape is not ideal and should not be used for sealing purposes on other types of threads, amongst which:  

AN (Army/Navy)  BSPT (British Standard-Taper Pipe-Thread)   GHT (Garden-Hose Thread)  NPSI (National-Straight Intermediate-Pipe)   NPSM (National-Pipe Straight-Mechanical)   NST (National Standard-Thread)  IN CONCLUSION  

Teflon tape is a very useful tool when it comes to sealing pipes and reducing the risks of leaks and dripping over time. It can be used for water lines, gas lines and drainage pipes, and it can resist to higher temperatures. Additionally, a pipe dope can be used on top of the tape to ensure a more permanent seal.

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