Should I use PTFE Tape with Compression Fittings?

PTFE (Polytetrafluoroethylene) tape, often referred to as Teflon tape, is a versatile tool commonly used in plumbing to seal pipe threads, ensuring leak-free connections. However, when it comes to compression fittings, there is often confusion about whether PTFE tape should be used and, if so, how to use it correctly. This guide will cover everything you need to know about PTFE tape and compression connections, including the small instances where it can be helpful and proper application techniques.

Type A Compression Fittings

Flowflex Compression Fittings are the perfect solution for your plumbing needs, offering unparalleled reliability and ease of installation. Crafted from high-quality materials, these fittings ensure a secure and leak-free connection, making them ideal for both residential and commercial applications. Our compression fittings are designed and manufactured to BS EN 1254 standard, providing you with peace of mind and long-lasting results.

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Understanding Compression Connections

Compression fittings are widely used in plumbing and gas installations because they provide a reliable seal with simple tools and without the need for soldering or welding. This makes them one of the easiest fittings to install, but also the safest.

The main components of a Compression Connection are:

• Compression Nut: A threaded nut that tightens over the fitting body.

• Compression Ring (or Olive): A metal ring that compresses between the nut and fitting body to form a seal.

• Fitting Body: The main part of the fitting that connects to the pipe.

• Pipework: Copper, Plastic or Steel Pipe.

When the Compression Nut is tightened, the Olive compresses between the pipe, the Fitting Body and the Nut, creating a leak-proof seal. Compression Fittings are commonly used with copper, plastic, and sometimes stainless steel pipes in plumbing, heating, and gas systems.

Should You Use PTFE Tape with Compression Fittings?

PTFE tape is not required to form the seal in a compression fitting because the seal is formed by the olive compressing onto the pipe, with a metal on metal joint between the nut and the body. It is not made by the threads. Nevertheless, in certain instances, PTFE tape can enhance your installation:

• Lubricating Threads
  Applying PTFE tape to the threads of the compression nut can act as a lubricant, making it easier to tighten the fitting and reducing the risk of damage to the threads during installation.

• Minor Leak Prevention
  In cases where a fitting is prone to minor leaks, for example in older fittings, a small amount of PTFE tape can help create an additional barrier to prevent leaks.

• Corrosion Prevention
  PTFE tape can also serve as a protective barrier, helping to prevent corrosion of the threads over time, especially in aggressive environments.

When Not to Use PTFE Tape with Compression Fittings

While PTFE tape can sometimes be an enhancement, here are instances when PTFE tape should not be used:

• Do Not Apply PTFE Tape on the Olive
  The olive is specifically designed in conjunction with the nut and the fitting body to compress directly against the pipe and the fitting body. Applying PTFE tape to the olive will interrupt this process and prevent proper compression, leading to leaks.

• Avoid Excessive Use
  Over-applying PTFE tape to the threads of the fitting can cause misalignment, making it difficult for the olive to achieve a proper seal.

• High-Pressure Connections
  For high pressure connections, compression fittings rely on precise metal-to-metal contact for making the seal. Adding PTFE tape can interfere with this contact, potentially leading to leaks.

Proper Application of PTFE Tape with Compression Fittings

If you do choose to use PTFE tape with compression fittings, it’s essential to apply it correctly to achieve the desired benefits without compromising the joint’s integrity. Follow these steps for proper application:

1. Wrap the Threads, Not the Olive
   Begin by wrapping the PTFE tape around the threads of the compression nut, not the olive or the fitting body. Start at the end of the threads and work your way back towards the body of the fitting.

2. Apply the Tape in the Correct Direction
   Wrap the tape in the same direction that the nut will be tightened (usually clockwise). This ensures that the tape does not unravel when the nut is screwed onto the fitting.

3. Use the Right Amount of Tape
   The thickness of PTFE tape can vary with different manufacturers, so there is no strict rule here. However, too much tape can cause difficulties in tightening the nut properly, while too little may not provide the desired lubrication or protection.

4. Smooth and Press Down the Tape
   Once wrapped, press the tape into the threads with your fingers to ensure it adheres well and doesn’t bunch up during tightening.

5. Tighten the Fitting
   After applying the tape, tighten the compression nut using a suitable spanner. Make sure not to over-tighten, as this can damage the olive or deform the pipe, leading to leaks.

Best Practices for Using PTFE Tape with Compression Fittings

• Use Quality Tape
  Not all PTFE tapes are created equal. Use a high-quality tape that is rated for plumbing or gas applications, depending on your system requirements.

• Do Not Apply Tape to the Compression Olive
  As already mentioned, the primary focus of the design of a compression fitting is to create a leak-proof seal with the olive. Adding tape to these surfaces can disrupt the compression seal and lead to leaks.

Wrapping Up

PTFE tape is not necessary for the installation of a Compression Fitting, but some do prefer to use to enhance their installations. Provided it is used correctly and only on the threads of the compression nut, it can help in certain instances.