Posted by Ben Proudlove on Tue, Aug 18, 2009 @ 02:24
If you google Teflon Tape the very first result is the wikipedia page that describes Teflon tape as
“Thread seal tape — commonly known as “Teflon tape”, “PTFE tape”, “tape dope”, or “plumber’s tape” — is a polytetrafluoroethylene (PTFE) film cut to specified widths for use in sealing pipe threads. The tape is wrapped around the exposed threads of a pipe before it is screwed into place. Since the PTFE is malleable, deformable and impermeable, it acts a little like putty under compression, being forced into small gaps between threads in order to create an air- and watertight seal when threaded into a joint. The tape is commonly used commercially in pressurized water systems, such as central heating systems, as well as in air compression equipment and thread joints with coarse threads.”
And then futher on in the same chapter
“Over-use, or mis-application of thread tape may be a hazard. As the tape material is so soft, excess or overhangs may easily break off and form a foreign body contaminant that could jam a valve seat etc.
Thread sealing tape is almost entirely applied by hand, owing to the ad hoc nature of most repair work”
Teflon also has a melting point of around 327degC, but its properties degrade above 260degC according to DuPont (the manufacturers of teflon).
We get asked about this a lot, so let me explain, the Autoclave Engineers range of reactors that we supply in the UK (see our Merrow Scientific reactor page) use a Metal to Metal engineered sealing for all of their valves, fittings and tubing, so no teflon tape.
The benefits of this method include:
- » Precise, repeatable and highly rated sealing
- » All parts are serial numbered so you can easily swap or replace
- » High temperatures and extremely high pressures are no problem
- » No welding (which could potentially have weak points which could lead to failure under pressure and are permanent and not easily replaced or repaired)
- » And no plumber’s tape……