Gasket requirement

E. Chang and G. E. Duim, "Injection Molding of Polyacryhc Gasketing Requiring No Postcure", SAE Technical Paper Series 900202 Detroit, Mich., Feb. 26-Mar. 2,1990. 

Plate-and-frame units have been developed for some small-scale applications, but these units are expensive compared to the alternatives, and leaks through the gaskets required for each plate are a serious problem. Plate-and-frame modules are now only used in electrodialysis and pervaporation systems and in a limited number of reverse osmosis and ultrafiltration applications with highly fouling feeds. An example of one of these reverse osmosis units is shown in Figure 3.39 [111],... 

Table 2 Vertical Force Applied to Valve Ferrule During Crimping and the Extent of Compression of the Sealing Gasket Required for Different Containers...

Other encapsulation applications of polymers for specific designs Include soil, ultraviolet, and abrasion-resistant front covers. The cover can serve as a transparent structural superstrata. Substrate support designs require a hard, durable front cover film to protect the relatively soft pottant from mechanical damages and excess soil accumulation. A polymeric front cover must be low In cost, highly transparent, and weather resistant to compete with glass. For applications out of the optical path between the sun and the solar cells (adhesives. Insulation, edge seals, gaskets) requirements for polymeric use In encapsulation are the same as for other applications. 

Wet chlorine gas, that is to say gas at low pressure, does not require tongue-and-groove flanges and can be confined by soft PVC and most of the common elastomers. Some polymeric gaskets require steel reinforcement, and some develop protective layers of chlorinated polymer. 

All metal gaskets required where temperatures exceed 930°F. 

Determine gasket proportions a. Area of gasket required ... 

Cylindrical casings, with no gasket required, are also used, but these require axial disassembly from the ends. Special tools and greater floor space are then needed to remove the rotating assembly. 

Serrated gaskets require a smaller seating force than flat gaskets and thus are used in screwed flanges where friction forces are to be minimized. 

Enichem and DuPont ate two suppHers of acryHc elastomers. It is estimated there ate - 9000 t/yr of these elastomers used in the United States. The principal uses of acryHc elastomers ate in automotive appHcations requiring both oil and heat resistance. These include transmission, valve stem, crankshaft, pinion, and odpan gaskets and seals. In addition hose, tubing, toUs, and belts ate made from acryHc polymers. 

Many antioxidants ia these classes are volatile to some extent at elevated temperatures and almost all antioxidants are readily extracted from their vulcanizates by the proper solvent. These disadvantages have become more pronounced as performance requirements for mbber products have been iacreased. Higher operating temperatures and the need for improved oxidation resistance under conditions of repeated extraction have accelerated the search for new techniques for polymer stabilization. Carpet backiag, seals, gaskets, and hose are some examples where high temperatures and/or solvent extraction can combine to deplete a mbber product of its antioxidant and thus lead to its oxidative deterioration faster (38,40). 

V-clamp joints (Fig. 10-140) are attached to the pipe by butt-weld or expanded joints. Theoretically, there is only one relative position of the parts in which the conical surfaces of the clamp are completely in contac t with the conical surfaces of the stub ends. In actual practice, there is considerable flexing of the stub ends and the clamp also complete contact is not required. This permits use of elastomeric gaskets... 

---