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

More documents

Recommendations

Info

XXVIII. ASBESTOS PACKINGS A. Product Description The term packings is generally assigned to the subset of packings that are designated~asdynamic (static packings are gaskets). These dynamic or mechanical packings are used to seal fluids in devices where motion is necessary. Examples where these packings have traditionally been used are in pumps, valves, compressors, mixers, and hydraulic (piston-type) cylinders (Kirk-Othmer 1981). Within the mechanical packing segment there are various types of packings (e.g., compression, automatic, and floating packings), but only compression packings are or have been made using asbestos fibers (FSA 1983). Asbestos-containing compression packings can be formed into various shapes for different uses as illustrated in Figure 1. The simplest form of compression packings (hence forward packings) is of the loose bulk type. Bulk formulations consist of blends of loose fibers and dry lubricants that are bound with a liquid or wax binder. These simple packings have only limited applications (e.g., packings for injection guns) and are not considered in the remainder of this report. Fiber mixtures are more often extruded with a binder and lubricant and used as a core in packings that have a braided yarn jacket that imparts greater durability to the packing (Kirk-Othmer 1981). The braided variety of packings are the most prevalent and all of the well-known packing manufacturers produce them by similar methods of construction. Asbestos packings are braided of strong, highest quality pure asbestos yarn. In addition, they may be constructed using an Inconel(R) or other wire insert around a resilient asbestos core impregnated with graphite. They are lubricated throughout and surfaced with anti-frictional dry lubricant graphite (EPRI 1982). The simplest form of braided packing is the square braided variety that utilizes asbestos yarns of the six grades defined -1-
Bulk Square braád Rolled (over core) Folded and twésted W formed Interlocking braid Round braid (three jackets over core) Figure 1. O~~ww~ L~’~of Cxr~t-~siaiPackings. (Scxirc~: Kirk—Ottmer 1981).
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: REFERENCES Carborundum. 1986. Produ
Page 19 and 20: Table 1. Standards of Asbestos Yarn
Page 21 and 22: A. ‘I’ A. ‘-I PRESSURE ~ Movi
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?