Gasket Fabricators Association Technical Committee Presentation Estimator’s Guide to Basic Gasketing Module 1 of 5 Understanding the Application September 2009

Definition Gaskets save money by allowing less precise mating surfaces on machine parts which can use a gasket to fill irregularities. Gaskets are mechanical seals that fill the space between two surfaces that fail to perfectly meet, generally to prevent leakage between the two objects while under compression. A gasket stores energy, like a spring.

Gasket Requirements Conform to the mating surfaces to achieve a seal. Durability. Resistant to medium being sealed. Meet or exceed all environmental requirements. Temperature Cavity Pressure Compressive Stress

Gasket Requirements Other Considerations: Zero leakage through the gasket. Affordable. Environmentally safe. Accommodate surface finish conditions of flanges. Reduce and/or control flange or port distortion.

Gasket Requirements Other Considerations (continued): Accommodate thermal expansion and contraction. Possess adequate recovery. Minimize torque loss caused by creep relaxation. No re-torque. Transfer heat, as desired. Close tolerance on compressed thickness. Meter fluid. Provide acoustic or thermal isolation. Possess anti-stick properties.

Gasket Requirements Other Considerations (continued): Pass customer verification testing Manufacturing / Handling Robotics Cleanliness Block Visibility for sensors Fit Recyclability

Gasket Design Gaskets are everywhere! Every application is unique!

Gasket Design Variables Compression Force. Temperature. Chemical Environment. Type of Flange. Surface Finish. Sealing Stress. Sealing Force. Material Selection. Gasket Configuration.

Design Tips Tips to help lower manufacturing cost, improve quality of product and/or shorten delivery time. Dimensional variations of flexible parts Compression, stretching or shrinking occurs during the manufacturing process Tolerance specifications Often are metal tolerances, tighter than needed Tolerances: +/- .015 inch typical

Design Tips Flashing Cut-Outs Prevalent with harder materials (plastics & reinforced rubber). Fragments sometime break off before die is completely through the material. Placing another material underneath the harder material when die cutting helps reduce flashing. Cut-Outs Generally are a problem when diameter or width of an opening in the part is less than the thickness of the material. Materials bind in die.

Design Tips Deformation of the material Materials stretch during the stamping process, causing an edge not to be straight, but usually concave. Usually when the ratio of wall thickness to material thickness is low. Can be minimized in die design & material selection. Cutting with laser or water jet machines usually solves the problem, but adds substantially to the cost. Die cutting hard material (plastic) The die cut edge may be tapered due to taper in die itself.

Design Tips Material thickness tolerance range There is an industry standard tolerance for all materials. Example: 3/4 inch thick foam can vary as much as 1/8 inch. If your application calls for tighter control than the standard, the material must be special ordered.

Seal Costs The true cost of a seal must take into account several parameters: Initial cost of the seal. Effectiveness / Reliability. Time between replacement. Cost of seal replacement. Cost of equipment downtime.

Seal Costs A continuous drip from a pump gland can amount to 4-5 liters/hour of product loss – or over 40,000 liters/year. Leaks reduce efficiency and increase energy loss. Environmental Parameter: ZERO LEAKAGE

Customer/Supplier Partnerships Understanding one another’s needs can reduce cost & increase performance for both companies. Things to consider in building a partnership for optimum performance. Application An in-depth understanding of your needs (application) & what is most important to you. “Pay me now or pay me later” options. Recommendations by the experts.

GFA Technical Handbook Describes gaskets, processes, and gasketing materials. Acquaints fabricators with industry standards for production methods, procedures and dimensional tolerances. Useful guide for gasket designers and gasket purchasers. Download @ http://www.gasketfab.com/

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

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