Despite the plethora of compression packing choices, the reality is that the overwhelming majority of applications can be satisfied with 6 styles of compression packing. This blog aims to bring some order out of the chaos!
First of all, as the compression packing industry in North America has evolved, asbestos packing is no longer manufactured or offered. In addition, jute, ramie, and flax packing are rarely requested because of the very limited application ranges which these materials support. This leaves 3 raw materials of choice from which to fashion compression packing: PTFE, graphite, and carbon.
PTFE, graphite, and carbon are preferred materials for high-quality compression packing because they have excellent handling characteristics and support a wide range of temperatures and pH values. Choosing packing made from PTFE, graphite, or carbon will satisfy most applications. The chart below summarizes the applications which each of these 3 types of packing will service, together with the style numbers of the relevant Teadit compression packing stocked by Canada Rubber Group Inc. (CRGI).
Packing Material
Teadit Style
Operating Conditions
Typical Applications
Synthetic yarns impregnated with PTFE, coated with PTFE lubricant.
Teadit 2019
pH range: 2-12Temperature: 450°F
Shaft speed: 2300 fpm
Animal fats, vegetable oils, synthetic oils, mild alkalis, mild inorganic acids.
Pure PTFE filament, protected with an FDA-approved lubricant.
Teadit 2006FDA
pH range: 0-14Temperature: 500°F
Shaft speed: 2300 fpm
Drinking water, chlorine, refrigerants, moderate caustics, solvents.
Graphite particles totally encapsulated by expanded PTFE fibers.
Teadit 2007
pH range: 0-14Temperature: 500°F
Shaft speed: 4900 fpm
Strong caustics, hydrogen peroxide, strong acids, solvents, fuels, oils, cooling fluids.
Expanded flexible graphite, reinforced corners using high-purity carbon fibers.
Teadit 2202
pH range: 0-14Temperature: 850°F
Shaft speed: 4000 fpm
Steam, pulp stock, mining slurry, acids, sulphuric acid 75-98% concentration.
Carbon fiber, impregnated with graphite particles.
Teadit 2002
pH range: 0-14Temperature: 850°F
Shaft speed: 4000 fpm
Potash, cement, abrasive slurries, nuclear applications, sulphuric acid 99% concentration.
Flexible graphite filament, reinforced with inconel wire jacket.
Teadit 2236
pH range: 0-14Temperature: 850°F
Steam: 1200°F
Static: 6500 psi
All valve steam packing applications other than FDA required valves.
Applications involving highly abrasive and corrosive media are usually problematic and troublesome. Often, a carbon or graphite compression packing, either alone or as a combined set, will handle most of these types of applications well. Using a dense carbon packing as an end ring, next to the pump impeller, along with a number of graphite rings to facilitate lubrication in the middle of the stuffing box, will result in an effective seal 99 per cent of the time. The trick is getting the packing combination set in the correct order; achieving the correct order results in an optimum service and an ideal installation.
Choosing the right compression packing need not be the daunting task it often is. By following the guidelines presented in the chart above, you should be able to achieve a non-problematic and leak-free stuffing box.
At CRGI, we are always available to help customers with any compression packing problem or issue. Whether it's advising on the choice of the right packing from our line of quality Teadit products, providing guidance with troublesome leaks or installations, or supporting you with installation information, we can help.
To find out how CRGI can help with your compression packing needs, contact CRGI fluid sealing specialist Bill Searle at crg@canadarubbergroup.com.