Of the many forms of PTFE braided packing, the right choice takes advantage of its strengths and minimizes its limitations. If selected and applied incorrectly, poor performance and increased maintenance can result. To apply PTFE effectively, one must understand the properties of the material. A few unique properties of PTFE make it an excellent ingredient for braided packings:
- Excellent chemical resistance. A major reason for using PTFE in packing materials is that it is unaffected by a wide variety of aggressive fluids, including very strong acids, bases, and solvents. Perhaps most important is PTFE’s ability to withstand strong oxidizers such as nitric acid, chlorine dioxide, high concentration sulfuric acid, and others. PTFE may be the only practical option for applications involving these media.
- Low coefficient of friction in contact with most surfaces. The non-wetting, slippery, low friction behavior of PTFE is well known. This can help to reduce power consumption and generation of heat at the packing-shaft interface.
While PTFE has its strengths, certain properties of PTFE are not so desirable in many pump packing applications. Problems encountered with PTFE packings are usually the result of its poor thermal and mechanical properties:
- Cold flow, or creep, under pressure. As temperature increases, creep also increases. When pressure is applied to a 100 percent PTFE packing over a period of time, the packing may become a dense solid mass requiring frequent adjustment to maintain a seal. It will also have a tendency to extrude into clearances at the top and bottom of the stuffing box.
- Low thermal conductivity. When frictional heat is generated by contact with a high speed rotary shaft, pure PTFE has a tendency to absorb the heat, not allowing it to dissipate to the surroundings. Higher leak rates across the packing-shaft surface are required to keep a PTFE packing from burning or charring.
- High coefficient of thermal expansion. As temperature increases, PTFE expands at a much faster rate than the surrounding metal. This expansion can create an increase in the pressure the packing puts on the pump shaft and bore.
Graphite PTFE Packing Rope is flexibility allows the shaft to run freely as well as leak proof.its proven performance and most economical are the main reasons for its success.
Graphite filled PTFE yarn is used to manufacture this packing.
- Special packing with excellent anti friction properties and lubricity.
- This packing is chemically inert.
- Our graphite PTFE packing is widely used in valves, chemical pumps, centrifugal pumps, rotary pumps, etc.
- Ph range: 0 to 14
- Temperature range: ( – 200 to 270 c)
- Pressure: 230bar.