About seal research and development system application. First, we analyze the R&D process of scanner product development. Second, we develop R&D ontology, define the knowledge flow and the interaction between R&D and KM process. Third, we build the conceptual model, define the issues, specified functional requirements of the model. Forth, we use the tool to build the system and make primary examinations and evaluations. Finally, we present the unique features, functions, potential benefits, limitations and possible extensions of the model.   Fluid Compatibility Type of Fluid to be Sealed Nitrile Polyacrylate Silicone Fluoroelastomer Engine Oil (SAE 30 Wt.) VG VG VG VG Engine Oil (SAE 10 Wt.) VG VG G VG Gear Oil (Super Gear) VG VG F VG Gear Oil (Hypoid Gear) G G NR VG Turbine Oil No. 2 G G G VG Machine Oil No. 2 G G F VG Automatic Transmission Fluid VG VG F VG Petroleum Base Lubricating O il VG VG F VG Gasoline F NR NR VG Light Oil/Kerosene F NR NR G Cutting Oil VG G F VG Grease VG VG VG VG E.P. Lubricants G VG NR VG Water-Glycol VG NR G F Alcohol VG NR G F 20% Hydrochloric Acid Solution F F F VG 30% Sulfuric Acid Solution F F NR VG   * Special compound available VG - Very good G - Good for most applications F - Fair, can be used if no other materials available but otherwise not recommended NR - Not recommended   Peripheral speed and number of revolutions Different designs of the sealing element affect the magnitude of the friction generated and thus the resulting temperature rises. As a result the various designs of the sealing element allow different maximum peripheral speeds. Figure shows the approximate maximum values for the permissible speed for sealing elements (without dust lip), made with materials NBR, ACM, FKM and MVQ, with no differential pressure, and where adequate lubrication or cooling of the sealing edge by the sealed medium exists. In addition the maximum permissible operating temperature shown in Table III must not be exceeded. The curve shows that higher peripheral speeds are permissible for larger shaft diameters than for smaller. This is due to the fact that the cross-sectional area increases in proportion to the square of the diameter, thus increasing the heat dissipation capacity.     *Permissiblespeedsinpressure-freestatetoDIN3761     Materials: Sealing Lip Materials Silicone (VMQ) Ethylene Propylene (EPDM) Nitrile (NBR) Epichlorohydrine Ethylene Oxide (ECO) Polyacrylate (ACM) Styrene-Butadiene Rubber (SBR) Fluoroelastomer (Viton) (FKM) Hydrogenated Nitrile (HSN) Fluorosilicone (FVMQ) Butyl Rubber (IIR) Ethylene Acrylic (AEM) Natural Rubber (NR)   At CHO, we work with virtually every single base polymer that is commercially available. This allows us to use the optimum material for each customer’s application.   Lip/Elastomer Information One of the most important components of the seal is the elastomer material. CHO has developed elastomer blends to meet a wide variety of sealing requirements. Available are many classes of materials with individual formulas to satisfy various sealing conditions. The data below provides general information and fluid compatibility ratings.   General Elastomer Information Base Polymer Nitrile Polyacrylate Silicone Fluoroelastomer Temperature Range* -50°F ~ 250° -20°F ~ 300° -80°F ~ 400° -30°F ~ 400°   -45°C ~ 125° -30°C ~ 150°C -60°C ~ 200°C -35°C ~ 200° Oil Resistance VG VG G VG Acid Resistance G F F F Alkali Resistance G NR NR F Water Resistance G F G G Heat Resistance G VG VG VG Cold Resistance G F G F Wear Resistance VG VG G VG Ozone Resistance G VG VG VG   * Maximum temperature limits dependent on other operating conditions. VG - Very good G - Good for most applications F - Fair, can be used if no other materials available but otherwise not recommended NR - Not recommended NOTES: 1. Phosphate Ester and Water Glycol hydraulic fluids are not included in the Table 2. Water resistance includes steam. No material is ideally compatible, as lubricity of water is very poor. 3. PTFE, Ethylene Acrylate, and other elastomers are available.     ADVANTAGES DISADVANTAGES Nitrile (NBR) ． Commonly referred to as Buna-N and a Copolymer of Butadiene and Acryonitrile ． Low cost ． Good resistance to petroleum oils, water, silicone oils, greases, glycol base fluids ． Good abrasion resistance, cold flow, tear resistance ． Poor resistance to ozone and weather aging Polyacrylate (ACM) Polyacrylate (ACM) ． Polymerised acrylic acidesters ． Good resistance to mineral oils, hypoid gear oils, E.P. additives, greases, aging and flex cracking ． Higher temperature limit than Nitrile ． Fair cold temperature limit ． Lower mechanical strength ． Costs slightly higher than Nitrile ． Poor dry running ability, water esistance Silicone (VMQ) ． Broad temperature resistance ． Good ozone resistance ． Resistant to compression set ． Low resistance to hydrocarbon fluids like gasoline or paraffin fluids or steam above 50 psi ． Cost is higher than Polyacrylate Fluoroelastomer (FKM) ． Good temperature resistance ． Compatible with wide range of fluids ． Commonly chosen as high temperature replacement of Nitrile or Polyacrylate ． Fair resistance to water, dry running ． Low temperature resistance is fair ． Cost is high       Copyright © 2007 Champ Oil Seals Industrial Co., Ltd. All rights reserved. No.10, Yumg-hsing Rd., Nantou County 540, Taiwan. Tel:886-49-2256276 Fax: 886-49-2256295 E-mail: cho.oilseal@msa.hinet.net　B2B Global-Trade, Global Machine, Global Bicycle.