Expand Your Knowledge Limit About the Packing Fibers

One of the most common and oldest sealing devices is compression packing, made from different sealing packing fibers. It prevents other rotating equipment and extends the lives of valves, pumps, and product leakage. Packing compresses within the stuffing box are constructed of relatively soft materials, between the body of the valve or pump and the rotating member to form a seal.

Pressure transmits to the packing set by tightening the gland against the outboard ring, which creates the seal that expands the rings radially. The different designs of packing braid include: twisted, square braid, multi-lock, braid over braid, and braid over the core.

For selecting a packing, three major criteria needed include:

• PH of the pumped fluid
• Fluid temperature
• Shaft speed

Specifies must research the different types of fiber materials before selecting compression packing. Eight different types of packing fibers are available. According to their compatibility with the application, each should be chosen. The eight types are:

• Acrylic
• Flax
• Aramid
• Novoloid
• Expanded PTFE
• Filament polytetrafluoroethylene (PTFE)
• Graphite (including flexible graphite tapes)
• Carbon

PTFE Coated Packing

Many sealing packing China can be coated with PTFE when the superior chemical resistance of pure PTFE is not required to take advantage of PTFE's strengths and improve packing performance. Some of the weaknesses of a pure PTFE braid can be eliminated or reduced by these fibers.

To produce economical, general service packing exhibiting less sensitivity to adjustment, greater extrusion resistance, and higher resilience than a PTFE fiber braid Blended fiberglass and synthetic yarns can be coated with PTFE. To further increase the heat dissipation and speed capability characteristics of the braid, they can also be coated with a dispersion mixture of graphite and PTFE.

The most versatile packing materials are graphite and Carbon fiber braids with PTFE coatings. They have very good resilience, high-speed capability, excellent chemical resistance, and high-temperature capability. They also exhibit good abrasion resistance and are not prone to extrusion or softening at high temperatures.

You can choose a product by understanding the limitations and strengths of the various forms of braided PTFE packing from sealing packing supplier that will most effectively meet the valve or pump sealing demands of a process.