Gasket Fabricators Association Technical Committee Presentation Estimator’s Guide to Basic Gasketing Module 2 of 5 Material Selection December 2009

2 Agenda  Material Selection Criteria  Pros and Cons  PSAs  ASTM F104 & D2000

3 Material Selection Criteria  4 Main Criteria to consider when selecting a gasket material: –Operating Pressure –Bolt Load –Operating Temperature –Media

4 Operating Pressure  Pressure X Temperature Factor (Service Factor) –Multiply PRESSURE in PSI by TEMPERATURE in °F. –If value > 625,000 – a metallic gasket is required. –Each application is unique! Also consider seating stress, type of flange, etc.

5 Bolt Load  M + Y Values –M = Ratio between residual stress on gasket and internal pressure (Gasket Maintenance Factor). –The higher the “M” value, better against leaks. –Y = minimum gasket seating stress (initial assembly)  M + Y Values not as relevant due to newer gasketing materials.  New gasket constants initiated by Pressure Vessel Research Committee.

6 Operating Temperatures  Elastomers max out at ~ 600° F.  Compressed non-asbestos: 400° F continuous.  Beater-add: ° F.  Flexible Graphite: 800° F.  Continuous v. Intermittent  Non-standard gasketing materials (high temp paper boards, etc.)

7 Media  Primarily affects the elastomer… –So different polymers for each application.  Not just for chemicals and oil/fuel products. –Abrasives, weather, ozone –Food, water, dairy, pharmaceutical  Teflon – excellent chemical resistance! –Envelope or encapsulated gaskets  Flexible Graphite – broad range of chemical resistance.

8 Pros & Cons: Elastomers Pros  Cost effective.  Wide range of durometers – and sponge.  Seals under lower compressive loads.  Wide range of compositions. Cons - Wide range of compositions. - Limits on: –Temperature –Pressure –Compression set

9 Pros & Cons: Compressed Non-Asbestos & Beater Add Pros  Cost effective  Higher Pressures.  Higher Temperatures.  High resistance to seating stress. Cons  Dust and slivers.  Tool Wear.

10 Pros & Cons: Teflon Pros  Excellent Chemical Resistance.  Electrical Insulator.  Anti-Stick Properties. Cons  Cold Flow.

11 Pros & Cons: Flexible Graphite Pros  Good with most chemicals.  Good high temperature gasket – up to 5400° F in vacuum.  Low creep – reduces retightening. Cons  Fragile.

12 Gaskets with PSAs  Application environments  Adhesive chemistries  Product constructions

13 Pressure Temperature TimeSurface Texture Surface Energy Surface Contamination Surface Contour Environment: Solvents/Chemicals Temperature Exposure Surface: Application: UV Light Exposure Factors that can influence PSA success...

14 Three Types of PSA Chemistries  Rubber PSA (Indoor)  Acrylic PSA (Outdoor)  Silicone PSA (Wide Temp)

15 Common Constructions  Adhesive Transfer Tape or “Free Film”  Double- Coated Tape  Single-Coated Tape or Label stock --Carrier --PSA --Liner (optional) --PSA (Exposed) --Carrier --PSA (Liner) --Liner --PSA --Liner

16 Double-Coated vs. Unsupported Adhesive Double-Coated Tapes –Less conformable –Lower temp resistance –“Removable” –Reinforces substrate Free Film Adhesive –More conformable –Higher temp resistance –“Permanent” –Doesn’t reinforce substrate

17 ASTM F104 & D2000  Classification systems specifying properties of non-metallic gasket materials. –Non-metallic gasket materials described by specific physical & mechanical characteristics. –Rubber compounds classified under ASTM D2000. –Users can specify required properties. –Suppliers can report product properties. –EXAMPLES: ASTM F104 F ASTM D M2HK 714 A1-10B38

18 Appendix  ASTM F104 – Nonmetallic Gasket Classification  ASTM D2000  Elastomer Properties

19 ASTM F104

20 ASTM F104

21 ASTM D2000 How to Read a Line Call-Out ASTM D M 2 HK 7 14 A1-10, B38, C12, EF31, EC88, F15 Z1 The most common material classification system used in O-ring specification is probably "Standard Classification System for Rubber Products in Automotive Applications" or ASTM D This system is designed to aid in the selection of practical rubber products for specific environments and provided a "line call-out" designation for the specification of elastomer seal materials.  Specification Revision –This indicates the revision year of D2000 to which the line call-out makes reference.  Measurement Units –If an M is present, metric units will be used for tensile strength, termperature, and tear strength (MPa, °C, and kN/m respectively). If no M is present, English units will be used (psi, °F, and ppi respectively).  Grade Number –Indicates the level of test requirements to which a material may be subjected. Example, Grade – basic properties; Grades 2-9 require additional testing.  Type and Class –See next page for most common polymers type and class.

22 ASTM D 2000 Type & Class

23 ASTM D2000 How to Read a Line Call-Out ASTM D M 2 HK 7 14 A1-10, B38, C12, EF31, EC88, F15 Z1  Hardness (Durometer) –This number indicates durometer range in Shore A units ( ± 5 pts.). Example indicates a harness of 70±5 durometer.  Tensile Strength –Next 2 digits show minimum tensile strength – 14 in example above (metric) or 14MPa. If non-metric would be 20 (2031 psi).  Additional Requirement Suffixes –Letter & number combinations that indicate a material’s test and performance criteria per the Grade number indicated. Example above of A1-10, B38, EF31, EC88, F15 Z1. (see next slide)

24 Additional Requirements Suffix

25 Elastomer Properties

26 More to Come! Module 1: Understanding the Application Module 2: Material Selection  Module 3: Cutting/Processing Techniques  Module 4: Value Adding  Module 5: Monday Morning Quarterback: Actual Results vs. Estimation

27 Thank You! We appreciate your time and attention. Questions?