|Gaskets Committee Is Revising Standard Classification for Nonmetallic Gaskets |
An ASTM task group invites gasket manufacturers, engineers and end-users to review a revision of ASTM F 104, Standard Classification System for Nonmetallic Gasket Materials (2000). The revised classification system, being proposed within ASTM Committee F03 on Gaskets, will help users to specify or describe pertinent properties of commercial nonmetallic gasket materials.
The classification is intended to:
Encourage uniformity in reporting properties;
To provide a common language between suppliers and consumers;
To guide engineers and designers in the test methods commonly used for commercially available materials; and
To be versatile enough to cover new materials and test methods as they are introduced.
F 104 covers materials composed of asbestos, cork, cellulose, and other organic or inorganic materials in combination with various binders or impregnants. Some highlights of its revision are the:
Addition of a description for fiber-reinforced gasket materials, allowing users or manufacturers to list two fibers; a listing for rubber binders; and a fourth digit for any type of core material; and
Addition of Type-8 material, vermiculite, to Table 1.
The standard classification is based on the principle that nonmetallic gasket materials should be described, insofar as is possible, in terms of specific physical and mechanical characteristics, and that an infinite number of such descriptions can be formulated by use of one or more standard statements based on standard tests, the task group writes in F 104. Therefore, users of gasket materials can, by selecting different combinations of statements, specify different combinations of properties desired in various parts. Suppliers, likewise, can report properties available in their respective products.
Chairman Jim Lingenfelder says the task group arrived at a compromise to satisfy the needs of buyers and manufacturers involved in gasketing. [The revision] better describes fiber-reinforced sheet gasket, he says. This type of material typically is made with a rubber-binder and some type of reinforcing fiber and is used in automotive and industrial applications. Because technology has evolved, we now can describe it in terms of the different fibers that it contains and the rubber binder that holds it all together.
The task group is seeking a balanced representation of gasket stakeholders to review the revision. The present group represents the gasket and chemical manufacturing and general automotive areas. Were constantly trying to improve, says Lingenfelder, vice president for Technical Services, Gasket Resources Inc., Houston, Texas. Anytime we can get more people involved, the better.
Stakeholders involved in gasketing will benefit from the revised classification, including design and piping engineers, purchasers, equipment manufacturers, and end users. Hopefully the revised F 104 classification will help facilitate the correct material being specified for the application and supplied to the user, Lingenfelder says.
Two events in industry prompted the revision, he explains: First, there was an effort [by the U.S. military] to convert Federal Spec HH-C-576 for composition cork to an ASTM spec.
"Task group member Chris Armellini of the U.S. Defense Supply Center [Phila., Pa.] did a tremendous amount of work fitting the information from HH-C-576 into tables in F 104. He also found ASTM G 21 [Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi] which fit the mildew resistance requirements in HH-C-576. Secondly, committee members felt that non-asbestos fiber reinforced sheet gasket materials needed better descriptions, Lingenfelder says, and task group member, Pete Petrunich, Fluid Sealing Association, Wayne Pa., obtained this information for the revision, in part, from the European Sealing Association.
The revised Standard F 104 does not include materials normally classified as rubber compounds, since they are covered in ASTM D 2000, Classification System for Rubber Products in Automotive Applications. F 104 includes the facing materials for laminate composite gasket materials (LCGM) but materials normally classified as LCGM are not covered since they are included in ASTM F 868, Standard Classification for Laminated Composite Gasket Materials.
Lingenfelder encourages new membership on the committee. Besides what is happening with this standard, he says, the F03 Committee has lots of exciting things happening including our focus on international participation and functional testing that affect both automotive and industrial gasket applications.
To assist with the revision or obtain further technical information, contact Jim Lingenfelder, Technical Services, Gasket Resources Inc. (phone: 713/467-1316). Committee F03 meets Oct. 15-17, 2002 in Norfolk, Va., and Oct. 21-23, 2003 in Tampa, Fla. For membership or meeting details, contact Joe Hugo, manager of Technical Committee Operations, ASTM International (phone: 610/832-9740). //
Copyright 2002, ASTM