Sometimes we are asked about the various types of mechanical packing materials and constructions available. In this blog, we present the main types of constructions used in the manufacture of mechanical packing, as well as highlighting the main material types.
Mechanical packing: construction types
Essentially, there are 3 main construction types of mechanical packing generally available on the marketplace. Packing is manufactured in these construction types from a variety of materials, including aramid, carbon and graphite filament, flexible graphite, PTFE, and various synthetic fibers. These materials are generally application-specific, and it is important for users of packing to select the optimal material for their application at hand.
- Braid-over-braid. In this construction method, braids or jackets of yarns, rovings, or ribbons of material are brought together on a braiding machine. The size of the packing is obtained by superimposing layers of braid on top of each other. This construction type results in a resilient, high-strength packing that readily conforms to pump shafts and valve stems due to its individual jacket-over-jacket construction. Because this is a forgiving construction type, braid-over-braid packing will readily compensate for any minor misalignment of a pump shaft.
- Interlocked. Strands of yarns, rovings or ribbons of material are interlocked with each other along the length of the packing. This construction type results in a softer packing with internal spaces which can carry lubricant impregnated into the packing by the manufacturer. This type of packing is extremely strong, yet flexible and resilient, thus assuring a tight seal with minimal gland pressure. Mechanical packing of interlocked construction is often used on rotary pumps and equipment that runs at higher speeds and lower pressures.
- Plaited. A construction method where strands of material criss-cross each other through the body of the packing. This method results in a readily conformable packing of good strength that can carry a high amount of lubricant. This construction type is often used in older equipment which is well into its life cycle.
Teadit mechanical packing from CRGI
CRGI carries a full line of quality mechanical packing produced by Teadit and available in a range of styles that suit specific applications. Mechanical packing material types that we carry include the following:
- Carbon fiber and graphite
- Expanded PTFE
- Synthetic yarn
- Aramid yarn
If you have a mechanical packing need, our sales specialists will be pleased to speak with you to determine your application requirements. To find out more about any of the mechanical packing we can supply, please contact our sales department at firstname.lastname@example.org.