Rubber Linings

Dry chlorine has a great affinity for absorbing moisture, and wet chlorine is extremely corrosive, attacking most common materials except HasteUoy C, titanium, and tantalum. These metals are protected from attack by the acids formed by chlorine hydrolysis because of surface oxide films on the metal. Tantalum is the preferred constmction material for service with wet and dry chlorine. Wet chlorine gas is handled under pressure using fiberglass-reinforced plastics. Rubber-lined steel is suitable for wet chlorine gas handling up to 100°C. At low pressures and low temperatures PVC, chlorinated PVC, and reinforced polyester resins are also used. Polytetrafluoroethylene (PTFE), poly(vinyhdene fluoride) (PVDE), and... 

Although performance curves are valuable in assessing classifier performance, frequently the cyclone overflow size analysis is used more than the d Q of the cyclone. In practice, clusters of cyclones (in parallel) are used to handle large capacities. Cyclones are manufactured in sizes ranging from 0.01 to 1.2 m in cyclone diameter, ie, the cylindrical section at the top (2,10). Capacities mn from 75 to 23,000 L/min. Materials of constmction vary widely. Rubber-lined or aH-polyurethane cyclones are used when abrasion is a problem. 

Plastic-Lined and Rubber-Lined Steel Pipe. 10-100... 

Abrasive pumps are made of hardened metal or even rubber-lined to handle abrasive particles in high quantities with minimal erosion. 

Sulfuric Acid, Below 55% Hard Rubber Lined C.l. Special Rubber Carbon Steel Hastelloy C Ring Packing Special Rubber Special Rubber... 

Hydrochloric Rubber-lined steel Low tolerance for organic solvent impurities temperature limited... 

Rubber-lined steel For dilute not concentrated (oxidizing) strengths temperature limited according to rubber hardness and acid concentration steel fabrication must be properly done... 

Milk-of-lime transfer pumps should be of the open impeller centrifugal type. Pumps having an iron body and impeller with bronze trim are suitable for this purpose. Rubber-lined pumps with rubber-covered impellers are also frequently used. Makeup tanks are usually provided ahead of centrifugal pumps to ensure a flooded suction at all times. Plating out of lime is minimized by the use of soft water in the makeup tank and slurry recirculation. Turbine pumps and eductors should be avoided in transferring milk of lime because of scaling problems. 

Friction loss in rubber-lined pipe is usually considered equivalent to that in new steel pipe of one-half to one nominal size smaller, with little or no change due to aging, unless knowm conditions can be interpolated. For a given inside diameter, the friction loss is the same (or slightly less) than clean steel pipe. 

For 2-inch (nominal) and larger vinyl, saran, or hard rubber pipe, the friction loss does not exceed clean steel. With saran and rubber-lined pipe the loss is about equal to clean steel at the 2.5-inch size, increasing to 2 to 4 times the loss at the 1-inch size. 

These impellers are available in nearly any material of construction as well as rubber, rubber-lined, glass-lined. 

Water with solids in suspension Fine abrasives Single suction with end clearance wearing fits. If all particles pass through mesh screen, rubber lined pumps are available which will give many times the life of metal pumps, providing no chemical action or excessive temperature will deteriorate the rubber. Special rubber compounds can be applied to improve resistance to certain chemicals. Open, which allows better application of the rubber, except in larger sizes. Also made in closed type. 

Hydrochloric Acid, 32% (Alternate) Rubber Lined C. Iron Hard Rubber Carbon Steel Rubber or Plastic Ring Packing... 

The standard polymers used for rubber linings consist of materials that are cross-linkable macromolecules which, on mixing with suitable reactants that form strong chemical bonds, change from a soft deformable substance into an elastic material. These polymers include natural rubber and its corresponding synthetic, c/s-polyisoprene, styrene-butadiene rubber, polychloroprene, butyl rubber, halogenated butyl rubbers, acrylonitrile-... 

Butyl rubber, halogenated butyl rubber linings and ethylene propylene rubber linings have excellent chemical resistance at temperatures up to 120°C. There are cases where butyl rubber linings have been subjected to temperatures down to —65°C without deterioration. Linings based on these polymers do not exhibit good abrasion resistance, which can only be rated as fair. 

For satisfactory operation, the rubber lining must be adequately bonded to the substrate it is protecting. BS 6374 part 5 gives definitive load to peel levels for various elastomers, but it is usually required that, on separation, the rubber should tear rather than part either at the primer/rubber interface or the primer/substrate interface. 

The production of a rubber lining includes the preparation of the rubber compound followed by processing to form the lining sheet, substrate preparation, lining application, vulcanisation and inspection. All these stages require thorough quality control, especially compound manufacture and sheet preparation, as chemical resistance depends on satisfactory dispersion of the individual ingredients and undetected flaws in the sheet will cause problems in service. 

Unless test coupons are produced alongside the lining, the only method of testing the vulcanisation state is with a hand hardness meter. A Shore A or IRHD meter is used for soft rubber linings and a Shore D meter for ebonites. The usual specification is that the hardness has to conform to 5° of the specified hardness. There is no quantitative non-destructive test for the strength of the bond between the lining and the substrate and so such tests are usually carried out in the laboratory on a sample prepared from the materials used. 

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