Thread seal tape (also known as PTFE tape, Teflon tape, or plumber's tape) is a polytetrafluoroethylene (PTFE) film tape commonly used in plumbing for sealing pipe threads. The tape is sold cut to specific widths and wound on a spool, making it easy to wind around pipe threads. Thread seal tape lubricates, allowing for a deeper seating of the threads, and it helps prevent the threads from seizing when being unscrewed. [1] The tape also works as a deformable filler and thread lubricant, helping to seal the joint without hardening or making it more difficult to tighten, [2] and instead making it easier to tighten. [1] It also protects the threads of both pieces from direct contact with each other and physical wear and helps seal and prevent leaks from the connection.
Typically the tape is wrapped in the same direction the male threads go for tightening and is commonly used commercially in applications including pressurized water systems, central heating systems, and air compression equipment.
There are two US standards for determining the quality of any thread seal tape. MIL-T-27730A (an obsolete military specification still commonly used in industry in the US) requires a minimum thickness of 3.5 mils and a minimum PTFE purity of 99%. [3] The second standard, A-A-58092, [4] is a commercial grade which maintains the thickness requirement of MIL-T-27730A and adds a minimum density of 1.2 g/cm3. [4] Relevant standards may vary between industries; tape for gas fittings (to UK gas regulations) is required to be thicker than that for water. Although PTFE itself is suitable for use with high-pressure oxygen, the grade of tape must also be known to be free from grease.
Thread seal tape used in plumbing applications is most commonly white, but it is also available in various colors. It is often used to correspond to color coded pipelines (US, Canada, Australia, and New Zealand: yellow for natural gas, green for oxygen, etc.). These color-codes for thread sealing tape were introduced by Bill Bentley of Unasco Pty Ltd in the 1970s. In the UK, the tape is used from coloured reels, e.g. yellow reels for gas, and green for oxygen.
In Europe, the BSI standard BS-7786:2006 specifies various grades and quality standards of PTFE thread sealing tape. [5]
Thread seal tape is appropriate for use on tapered threads, where the sealing force is a wedge action. Parallel threads may not seal effectively with or without tape, as they are intended to be sealed by a gasket.
Thread seal tape is almost always applied by hand, although at least one machine is available for the production wrapping of fittings. [6] [7] [8]
Thread seal tape is also commonly used in the stretching of body piercings, through a process known as taping, because it is inert and safe for this use. The wearer wraps a layer of tape around a plug and uses the jewelry, adding another layer every few days, thus gradually stretching the piercing. [9]
Overuse or misapplication of thread seal tape may be a hazard. Excess application of tape can prevent mating threads from fully engaging, reducing the shear point of the threads. [10] Combining thread seal tape with a pipe dope compound can also overload threads. Also, internal overhangs of loose material may constrict a joint or slough off and form a foreign body that could jam a valve seat.[ citation needed ] Therefore, using tape as a thread sealant is generally not considered appropriate in fluid power (hydraulic) systems. Overheating (550° Fahrenheit, or about 288° Celsius) [11] and subsequent decomposition of Teflon can produce perfluoroisobutene which is 10 times as toxic as phosgene. Inhalation of even a minute amount can be fatal. [10] [ failed verification ]
Familiarity with the Teflon brand of fluoropolymers has led to the name becoming a generic trademark, and the practice of any PTFE-based thread seal tape is referred to as "Teflon tape". Chemours, owner of the Teflon trademark, no longer manufactures any thread seal tape, [12] and objects to this practice. [13]
Most references to "plumber's tape" nowadays refer to thread seal tape; however, the original use in the plumbing trade describes a strap of material with holes in it used for supporting pipes and fixtures. [14]
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene, and has numerous applications because it is chemically inert. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from DuPont, which originally discovered the compound in 1938.
Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal, and potable water delivery are among the most common uses for plumbing, but it is not limited to these applications. The word derives from the Latin for lead, plumbum, as the first effective pipes used in the Roman era were lead pipes.
A flange is a protruded ridge, lip or rim, either external or internal, that serves to increase strength ; for easy attachment/transfer of contact force with another object ; or for stabilizing and guiding the movements of a machine or its parts. Flanges are often attached using bolts in the pattern of a bolt circle.
A plumber is a tradesperson who specializes in installing and maintaining systems used for potable (drinking) water, hot-water production, sewage and drainage in plumbing systems.
A gasket is a mechanical seal which fills the space between two or more mating surfaces, generally to prevent leakage from or into the joined objects while under compression. It is a deformable material that is used to create a static seal and maintain that seal under various operating conditions in a mechanical assembly.
A tap is a valve controlling the release of a fluid.
A plumbing fixture is an exchangeable device which can be connected to a plumbing system to deliver and drain water.
American National Standard Pipe Thread standards, often called national pipe thread standards for short, are United States national technical standards for screw threads used on threaded pipes and pipe fittings. They include both tapered and straight thread series for various purposes, including rigidity, pressure-tight sealing, or both. The types are named with a full name and an abbreviation, such as NPT, NPS, NPTF, or NPSC.
A hose clamp (hose clip,hose lock or Jubilee Clip (UK)) is a device used to attach and seal a hose onto a fitting such as a barb or nipple.
A compression fitting is a fitting used in plumbing and electrical conduit systems to join two tubes or thin-walled pipes together. In instances where two pipes made of dissimilar materials are to be joined, the fittings will be made of one or more compatible materials appropriate for the connection. Compression fittings for attaching tubing (piping) commonly have compression rings, called ferrules or olives, in them, and are sometimes referred to as flareless fittings. There are also flare fittings that do not require ferrules/olives.
A screw thread is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a straight thread and the latter called a tapered thread. A screw thread is the essential feature of the screw as a simple machine and also as a threaded fastener.
A stuffing box or gland package is an assembly which is used to house a gland seal. It is used to prevent leakage of fluid, such as water or steam, between sliding or turning parts of machine elements.
A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipe is far stiffer per unit weight than solid members.
British Standard Pipe (BSP) is a set of technical standards for screw threads that has been adopted internationally for interconnecting and sealing pipes and fittings by mating an external (male) thread with an internal (female) thread. It has been adopted as standard in plumbing and pipe fitting, except in North America, where NPT and related threads are used.
A threaded pipe is a pipe with screw-threaded ends for assembly.
In piping and plumbing, a coupling is a very short length of pipe or tube, with a socket at one or both ends that allows two pipes or tubes to be joined, welded (steel), brazed or soldered together.
A fitting or adapter is used in pipe systems to connect sections of pipe or tube, adapt to different sizes or shapes, and for other purposes such as regulating fluid flow. These fittings are used in plumbing to manipulate the conveyance of fluids such as water for potatory, irrigational, sanitary, and refrigerative purposes, gas, petroleum, liquid waste, or any other liquid or gaseous substances required in domestic or commercial environments, within a system of pipes or tubes, connected by various methods, as dictated by the material of which these are made, the material being conveyed, and the particular environmental context in which they will be used, such as soldering, mortaring, caulking, plastic welding, welding, friction fittings, threaded fittings, and compression fittings.
FFKMs are perfluoroelastomeric compounds containing an even higher amount of fluorine than FKM fluoroelastomers.
A cam and groove coupling, also called a camlock fitting, is a form of hose coupling. This kind of coupling is popular because it is a simple and reliable means of connecting and disconnecting hoses quickly and without tools.
Perfluoroalkoxy alkanes (PFA) are fluoropolymers. They are copolymers of tetrafluoroethylene (C2F4) and perfluoroethers (C2F3ORf, where Rf is a perfluorinated group such as trifluoromethyl (CF3)). The properties of these polymers are similar to those of polytetrafluoroethylene (PTFE). Compared to PTFE, PFA has better anti-stick properties and higher chemical resistance, at the expense of lesser scratch resistance.