Gaskets are materials used to seal one compartment of a device ...

More documents

Recommendations

Info

used are valves and pumps employed in the electric power, petroleum refinery, petrochemical, chemical, nuclear power, and pulp and paper industries (Union Carbide 1987). Depending on the scale of these operations, asbestos packings of various shapes and sizes are required. As described earlier, the design of a packing is to control the amount of leakage of fluid at shafts, rods or valve systems and other functional parts or equipment requiring containment of liquids or gases. Packings are used in rotary, centrifugal, and reciprocating pumps, valves, expansion joints, soot blowers, and many other types of mechanical equipment (FSA 1983). Figures 2 and 3 illustrate the design of a typical pump with a packing set and the configuration of a packing, respectively. Depending on the conditions of use, various types of asbestos packings are used. The temperature and pressure of the system in which the packing is used determine the style of packing that is used and the type of additional constituents incorporated in the packing (e.g., other fibers, binders, fillers). Other factors that affect the composition and configuration of the packing system include: the rotation speed of the valve or pump member, the type of fluid being contained (i.e., caustic, acid, alcohol, petrochemical), and the amount of time between scheduled maintenance operations (FSA 1983). Table 2 identifies the different packing types traditionally made from asbestos fibers, their service areas, and the conditions under which typical operations are performed. 2 Asbestos is used in packings because of its unique combination of heat and chemical resistance as well as its low price. The important attributes of asbestos fiber for this application are the following: 2 It should be noted that packings can be used in varying applications and are not strictly limited to certain operating conditions. Table 2 gives likely use areas and conditions, but these are not limiting designations. -5-
A. ‘I’ A. ‘-I PRESSURE ~ Moving shaft Adjustable pressure A. LEUAGE ~ompression_packiflg set Figure 2. I~7pi~].Stiff ing B~c~r~tn~tiai Utilizing pr~siai Packings for Eff~tinga Dynamic Seal. (Scxirc~: PSA 1983).
Page 1 and 2: XXVII. SHEET GASKETS A. Product Des
Page 3 and 4: Table 1. Fluid and Pressure Ranges
Page 5 and 6: $20.5 million in 1985, based on an
Page 7 and 8: Table 3. Substitutes for Asbestos S
Page 9 and 10: Aramid gaskets are usually composed
Page 11 and 12: esistance. A wire insert is often a
Page 13 and 14: 6. Ceramic Fiber Mixtures Ceramic f
Page 15 and 16: REFERENCES Carborundum. 1986. Produ
Page 17 and 18: Bulk Square braád Rolled (over cor
Page 19: Table 1. Standards of Asbestos Yarn
Page 23 and 24: Table 2. Operating Conditions and U
Page 25 and 26: Table 3. Production of Asbestos Pac
Page 27 and 28: een forced to replace the asbestos
Page 29 and 30: Table 4. Estimated Market Share for
Page 31 and 32: useful temperature limit of approxi
Page 33 and 34: 6. Other Substitute Fibers Other fi
Page 35 and 36: Table 6. Data Inputs for Asbestos R
Page 37 and 38: TSCA Section 8(a) submission. 1982.
Page 39 and 40: a viscosity control for waterproofi
Page 41 and 42: Table 1. Production of Asbestos Roo
Page 43 and 44: or talc. The additives ease grindin
Page 45 and 46: Table 2. Manufacturers of Cellulose
Page 47 and 48: Cellulose bodied roof coatings and
Page 49 and 50: equivalent basis, they are favored
Page 51 and 52: compounds. These formulations have,
Page 53 and 54: . Other Roof Coatings and Cements O
Page 55 and 56: Table 4. Data Inputs for Asbestos R
Page 57 and 58: ATTACHMENT B PROJECTED PRICES ANALY
Page 59: ICF Incorporated. 1986 (July-Decemb

Gaskets are materials used to seal one compartment of a device ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?